Clinical and genetic profile of congenital long QT syndrome in Hong Kong: a 20-year experience in paediatrics

Hong Kong Med J 2018 Dec;24(6):561–70  |  Epub 3 Dec 2018
DOI: 10.12809/hkmj187487
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Clinical and genetic profile of congenital long QT syndrome in Hong Kong: a 20-year experience in paediatrics
SY Kwok, MB, ChB, FHKAM (Paediatrics)1; Anthony PY Liu, MB, BS, FHKAM (Paediatrics)2; Cindy YY Chan, BSc1; KS Lun, MB, BS, FHKAM (Paediatrics)1; Jasmine LF Fung, BBiomedSc2; Christopher CY Mak, MB, ChB2; Brian HY Chung, MB, BS, FHKAM (Paediatrics)2; TC Yung, MB, BS, FHKAM (Paediatrics)1
1 Department of Paediatric Cardiology, Queen Mary Hospital, Pokfulam, Hong Kong
2 Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
 
Corresponding author: Dr Brian HY Chung (bhychung@hku.hk)
 
 Full paper in PDF
 
Abstract
Introduction: Congenital long QT syndrome (LQTS) is a genetically transmitted cardiac channelopathy that can lead to sudden cardiac death. This study aimed to report the clinical and genetic characteristics of all young patients diagnosed with LQTS in the only tertiary paediatric cardiology centre in Hong Kong.
 
Methods: This is a retrospective review of all paediatric and young adult patients diagnosed at our centre with LQTS from January 1997 to December 2016. The diagnosis of LQTS was established with a corrected QT interval (QTc) ≥480 ms, Schwartz score of >3 points, or the presence of a pathogenic mutation.
 
Results: Fifty-nine patients (33 males) from 52 families were included, with a mean age of 8.17 years (range, 0.00-16.95 years) at presentation. Five patients had concomitant congenital heart diseases. The mean follow-up duration was 5.33 ± 4.65 years. The mean QTc in the cohort was 504 ± 47 ms. They presented with syncope and convulsion (49%), cardiac arrest (10%), bradycardia and neonatal atrioventricular block (12%). Fifteen (25%) patients were asymptomatic at diagnosis. Thirty-eight (64.4%) patients were confirmed to have a pathogenic mutation for LQTS genes. Forty-five (76.3%) patients received beta blocker therapy. Thirteen (22.0%) patients required implantable cardioverter defibrillator. There was no mortality in the study period. The 1-, 5-, and 10-year breakthrough cardiac event–free rates were 93.0%, 80.7%, and 72.6%, respectively.
 
Conclusion: Identification of the disorder, administration of beta blockers, and lifestyle modification can prevent subsequent cardiac events in LQTS. Genotyping in patients with LQTS is essential in guiding medical therapy and improving prognosis.
 
 
New knowledge added by this study
  • Two-thirds of young long QT syndrome patients in Hong Kong carry pathogenic mutations. Concomitant congenital heart disease is present in 8.5% of these patients.
  • The current treatment strategy for young long QT syndrome patients in Hong Kong includes lifestyle modification, beta blocker therapy, implantation of a cardioverter defibrillator, and sympathectomy.
  • Young long QT syndrome patients in the present study have good prognosis. No mortality was reported in the medium-term follow-up.
Implications for clinical practice or policy
  • Genetic testing should be performed for all patients with clinical diagnosis of long QT syndrome, to facilitate timely genotype-guided therapy and early detection of affected family members.
  • The diagnosis of long QT syndrome should be considered in young patients presenting with syncope and convulsions, as well as those with bradycardia and atrioventricular block in early infancy.
  • Sudden cardiac death associated with long QT syndrome is preventable. Facilities for genetic testing and inherited arrhythmia assessment are recommended.
 
 
Introduction
Congenital long QT syndrome (LQTS) is a life-threatening cardiac arrhythmia syndrome, which leads to sudden death in young people.1 Congenital LQTS is characterised by prolonged QT interval (QTc) on electrocardiogram (ECG) and occurrence of syncope or cardiac arrest. During the past two decades, there have been major advancements in the understanding of the genetic factors underlying the clinical manifestations, prognosis, and subtype-specific therapy of LQTS.1 2 3Seventeen disease-causing LQTS genes have been identified, each of which can lead to dysfunction in the potassium, calcium, or sodium cardiac ion channels.4 In this study, we review the clinical characteristics, genetic profile, management strategy, and outcome of our local LQTS paediatric patients.
 
Methods
Study population
Our study included all children, adolescents, and young adults diagnosed with congenital LQTS from January 1997 to December 2016 in the Department of Paediatric Cardiology, Queen Mary Hospital, which is the only tertiary paediatric cardiology referral centre in Hong Kong. All except three patients were Chinese. Diagnosis of congenital LQTS was reviewed with reference to the 2015 European Society of Cardiology guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death.5 Long QT syndrome was diagnosed with either corrected QTc ≥480 ms in repeated 12-lead ECG measurements or LQTS risk score >3 points, as proposed by Schwartz et al.6 The presence of a confirmed pathogenic LQTS mutation, irrespective of the QTc, was also used for diagnosis of LQTS. Secondary causes of LQTS were excluded.
 
Demographic data, clinical presentation, family history, QTc at presentation, and genetic tests were retrospectively reviewed. Clinically important presentation was defined as clinical symptoms or rhythm disturbances that warranted concern. Incidental findings of isolated prolonged QTc were not regarded as clinically important presentation.
 
We reviewed the treatment modalities, including beta blocker therapy, implantable cardioverter defibrillator (ICD), permanent pacemaker, and left cardiac sympathetic denervation. Clinical outcomes up to December 2016 were summarised. Syncope, seizure, aborted cardiac arrest, appropriate ICD shock, or sudden cardiac death after diagnosis of LQTS were considered as breakthrough cardiac events.
 
Genetic test
Genetic tests were offered to all patients after informed consent was provided by their parents or guardians. Blood samples were sent to the Molecular Genetics Laboratory of Victorian Clinical Genetic Services, Melbourne, Australia, for genetic testing. Before 2014, six common LQTS genes were tested (KCNQ1, KCNH2, SCN5A, KCNE1, KCNE2, KCNJ2) by sequencing of the entire coding region of all known transcripts of the genes. Multiplex ligation-dependent probe amplification analysis was performed on five genes (KCNQ1, KCNH2, SCN5A, KCNE1, KCNE2) to detect deletions or duplications. After 2014, next-generation sequencing was used to identify mutations in an arrhythmia gene panel to replace sequencing of the six LQTS genes (details of the arrhythmia full panel can be found at http://www.vcgs.org.au/tests/cardiac-gene-panels). Before referral to our unit, 13 patients had genetic tests performed by local or overseas genetic testing centres.
 
Mutations in the LQTS loci classified as pathogenic or likely pathogenic were considered as genotype positive in our cohort. Cascade testing was offered to first-degree relatives of patients identified as genotype positive.
 
Statistical analysis
Statistical analysis was performed with the SPSS (Window version 17.0; SPSS Inc, Chicago [IL], United States). Continuous variables were expressed as mean ± standard deviation, median and range. We used the standard t test for comparisons of continuous data. The P<0.05 were deemed statistically significant. Kaplan-Meier survival curves were created with censoring at first breakthrough cardiac event or last follow-up, and analysis was made using the log rank test.
 
Results
Demographics and clinical characteristics
During the study period, 59 patients (33 males) in 52 families were identified who fulfilled the diagnostic criteria as described. Nine individuals were diagnosed by ECG screening of our index cases including a 25-year-old young adult. The mean follow-up duration of the cohort was 5.33 ± 4.65 years. Four patients were lost to follow-up, but no death was reported in the territory-wide Hospital Authority electronic patient record. Five patients were under the care of adult cardiologists at the follow-up.
 
Table 1 shows the characteristics of our patients. The mean age at diagnosis was 8.12 ± 5.19 years (range, 0-25 years). For those patients who had clinically important presentation, the mean age at presentation was 8.75 ± 5.12 years (range, 0.00-16.95 years). Boys were younger than girls at presentation (6.39 ± 5.00 years vs 10.51 ± 4.55 years, P=0.016).
 

Table 1. Cohort characteristics of patients with LQTS
 
The mean QTc of the cohort was 504 ± 47 ms. The median Schwartz score was 4 points (range, 1-6 points). Index patients had longer mean QTc (512 ± 46 ms) when compared with screened family members (462 ± 25 ms, P=0.002).
 
Five (8.47%) patients had congenital heart defects: secundum atrial septal defect (n=1; genotype negative), ventricular septal defect (n=1; LQTS type 2 [LQT2]), tetralogy of Fallot (n=2; LQT2 and LQTS type 8 [LQT8]), and transposition of great arteries (n=1; genotype negative). One patient had bilateral sensorineural hearing loss and was subsequently confirmed to have LQTS type 1 (LQT1).
 
Mode of presentation
Figure 1 illustrates the mode of initial presentation of our patients. Forty-four patients had clinically important presentation at diagnosis. Syncope without convulsion was the most common mode of presentation (37.3%), among which around 40% of cases were stress-related. Convulsion was also a common symptom (12%). Aborted cardiac arrest occurred in six (10.2%) individuals.
 

Figure 1. Genotypes and clinical presentations of our cohort of patients with long QT syndrome (n=59). (a) Genotypes and (b) clinical presentations of patients with long QT syndrome
 
Three patients presented with sinus bradycardia, one of whom was detected prenatally. Four patients, including three infants, had 2:1 atrioventricular (AV) block at diagnosis. A significant proportion of patients with LQTS (25.4%) did not have clinically important presentation at diagnosis; most of them had incidental ECG findings of prolonged QTc during medical check-ups or were identified by family cascade screening.
 
Treatment and outcome
The clinical outcomes of patients with LQTS in our cohort with clinically important presentation are summarised in Figure 2.
 

Figure 2. Outcomes of patients with long QT syndrome with clinically important presentation
 
Beta blocker
All patients were offered beta blocker therapy. However, 14 patients refused beta blocker (11 patients had clinically important presentation). Seven patients were on beta blocker but stopped subsequently.
 
Metoprolol was the initial choice of beta blocker for most of our patients (n=27), whereas 10 patients had atenolol as initial choice. Propranolol was used in eight infants. Eight patients receiving metoprolol, atenolol, or propranolol later changed to nadolol to enhance compliance or for better control of breakthrough symptoms. Mexiletine was added as an adjuvant therapy for five patients with LQTS type 3 (LQT3) who were symptomatic. Among the 31 patients with an initial history of convulsion, syncope, or dizziness (mean follow-up duration, 4.81 ± 3.84 years), 21 became asymptomatic after medication and/or lifestyle modification. Two patients who had recurrent symptoms after initial beta blocker therapy became event-free after a change from metoprolol/atenolol to nadolol. Patients without clinically important presentation at diagnosis remained asymptomatic with or without beta blocker therapy, irrespective of presence of documented pathogenic mutation.
 
Implantable cardioverter defibrillator
Implantable cardioverter defibrillator was implanted in 13 patients, whose mean QTc was 501 ± 42 ms. Six of these patients had initially presented with aborted ventricular tachycardia (VT)/ventricular fibrillation (VF) arrest. Five patients received ICD implantation because of recurrent symptom or subsequent VT/VF despite beta blocker therapy. Two of these five patients experienced appropriate shocks after ICD implantation. One patient with pathogenic KCNE1 mutation had syncope due to sinus arrest with long pauses; ICD was offered for primary prevention of sudden death in addition to pacing therapy. One patient who had AV block at birth developed subsequent unprovoked syncope at aged 6 years despite medical treatment and his pacing system was upgraded to ICD. In total, four patients experienced appropriate ICD shocks despite beta blocker treatment. There were no more ICD shocks after reinforcement of medication compliance, adjustment of dosage, and in one patient switching of metoprolol to nadolol.
 
Left cardiac sympathetic denervation
Left cardiac sympathetic denervation was performed via video-assisted thoracoscopic approach in two patients, together with ICD therapy. Both of them were free of cardiac events on follow-up.
 
Pacemaker
Pacemakers were implanted in five patients. Four of these five patients had functional AV block due to prolonged QTc. Normal AV node conduction recovered with time in these four children. The fifth patient had complete heart block after surgical repair of congenital heart condition (transposition of great arteries with ventricular septal defect).
 
The Kaplan-Meier survival curve is shown in Figure 3. Overall, the breakthrough cardiac event–free survival was 93.0% ± 0.034% at 1 year, 80.7% ± 0.065% at 5 years, and 72.6% ± 0.080% at 10 years for the entire cohort. Patients who had clinically important presentation at baseline had a higher risk of developing breakthrough cardiac events (P=0.048) compared with those who did not. There was no mortality during the study period.
 

Figure 3. Breakthrough cardiac event (BCE)–free survival in treated long QT syndrome patients
 
Genotype
All but four patients underwent genetic testing. Testing was not possible in two patients owing to loss to follow-up before genetic testing could be offered; these two patients were strong phenotypes of LQTS with Schwartz scores of 4 and 5 points, respectively. The other two patients were first-degree relatives of confirmed genotype-positive patients.
 
Seven patients were genotype negative. Four of them were tested before 2014. Nine patients had their mutated genes classified as variants of unknown significance. We also included three patients (LQT1, n=2; LQT2, n=1), reported by Mak et al,7 whose genetic tests were performed in a local laboratory.
 
Thirty-eight (69.1%) patients among those tested were confirmed to have pathogenic mutations for LQTS (Table 2). Eight mutations were novel (8/33, 24.2%). Most of the pathogenic mutations were missense mutation (30/33, 90.9%). Ten (16.9%) patients had LQT1 (KCNQ1). Twelve (20.3%) patients had LQT2 (KCNH2), whereas seven (11.9%) patients had LQT3 (SCN5A). Three patients had LQTS type 5 (KCNE1). There were five patients (three families) with LQT8 resulting from a rare pathogenic mutation in CACNA1C. LQT8 is linked to Timothy syndrome with multiple extracardiac manifestations. Only one of our patients with LQT8 had classical features of Timothy syndrome, with syndactyly, developmental delay, and congenital heart defect (tetralogy of Fallot). One patient had LQTS type 16 (CALM3). Figure 1 shows the details of the genotype information of LQTS genes identified.
 
Clinical characteristics of patients with LQT1, LQT2, or LQT3 are detailed in Figure 4. Syncope with stress was the predominant presentation in patients with LQT1 (60%). In contrast, syncope without stress was the main form of presentation in patients with LQT2 (41.7%). In patients with LQT3, around 30% had an initial presentation of aborted VF cardiac arrest. A high proportion (50%) of patients with LQT3 developed subsequent VT/VF despite medical therapy, compared with 14.3% in patients with LQT1 and 28.6% in patients with LQT2.
 

Table 2. Genetic information of our LQTS cohort (33 mutations in 38 patients)
 

Figure 4. Clinically important presentation of patients with LQT1, LQT2, and LQT3
 
Nine patients were identified to have LQTS during family screening of index patients. Two patients had strong phenotypes but did not have genetic tests. Five patients had LQTS phenotypes with confirmation by genetic testing. Two asymptomatic children in the same family were referred to us and were identified by cascade screening of their father’s pathogenic mutation.
 
Discussion
Long QT syndrome is a rare inherited disorder associated with an increased propensity to polymorphic VT/VF, syncope, and sudden cardiac death. In this report, we describe the clinical features and genetic profile of 59 LQTS paediatric patients managed in the only tertiary paediatric cardiology referral centre in Hong Kong over 20 years.
 
Long QT syndrome diagnosis
The prevalence of childhood LQTS was estimated to be 1:2000 in an Italian birth cohort.8 In a recent Japanese study, the estimated probability of diagnosing LQTS was 1:3300 in children aged 6 years and 1:1000 in those aged 12 years.9 Our results indicate that the prevalence of diagnosed LQTS in Hong Kong children was less than 1:10 000, suggesting an underdiagnosis of the condition. This is likely due to under-recognition of symptomatic LQTS in young patients who were treated for recurrent seizure and unexplained syncope. Without an ECG screening programme, many asymptomatic LQTS children also remain undiagnosed.
 
The lack of comprehensive screening for family members of adult LQTS probands is another reason for underdiagnosis, as only two children from a single family were referred to us from adult cardiologists over the 20-year study period. In addition, a 5-year-old child of a mother with known LQTS was not referred until he presented with convulsions.
 
Molecular autopsy for young victims of sudden cardiac death is not implemented in Hong Kong. In many developed countries, affected family members of LQTS sudden death victims are identified early through this pathway to prevent sudden cardiac death. We believe that the total number of symptomatic and asymptomatic young patients with LQTS in Hong Kong is much higher than what we have studied in our single tertiary referral centre.10 11
 
Long QT syndrome presentation
Congenital LQTS is usually diagnosed in patients presenting with syncope, unexplained seizure, and aborted cardiac arrest. The mean QTc of our patients was 504 ± 47 ms, and median Schwartz score of the entire cohort was 4 points (range, 1-6 points). This indicates that the patients that were referred to our centre were patients with more severe symptoms, resulting in a higher likelihood of a diagnosis of LQTS, based on clinical criteria.
 
Previous reports have shown that the risk of clinical events in boys (aged <15 years) with LQTS is significantly higher than that in girls with LQTS.12 In our cohort, we also confirmed that symptomatic boys were significantly younger than girl at diagnosis or presentation.
 
Sinus bradycardia and functional AV block are well reported in perinatal LQTS.13 14 15 The youngest patient in our group presented with fetal bradycardia. We also noted 2:1 AV block in three infants at presentation. Their AV conduction normalised with a significant decrease in QTc during follow-up. Paediatricians or family doctors should suspect LQTS in young infants with slow heart rates.
 
Long QT syndrome and structural congenital heart disease
Few links between LQTS and congenital heart disease have been reported, apart from Timothy syndrome. A recent single-centre review of 49 LQTS genotype-positive patients identified 11 (22%) cases with concomitant conotruncal anomalies and/or aortic arch anomalies.16 In our cohort, five (8.5%) patients with LQTS had concomitant congenital heart disease. Two cases were diagnosed in the perioperative period. Prolonged QTc in the context of congenital heart disease can be confounded by several factors, including postoperative electromechanical factors, intrinsic, or postoperative QRS abnormalities. Therefore, the diagnosis of LQTS could be masked in patients with congenital heart disease. We suggest that ECG of patients with congenital heart disease should be evaluated carefully for QTc.
 
Long QT syndrome genotype
Throughout the world, 75% to 80% of patients with LQTS have identifiable genetic mutations, with LQT1, LQT2, or LQT3 accounting for 90% of cases. Pathogenic LQTS genetic mutations were identified in 69.1% of the patients in our cohort who were tested, which is comparable with other LQTS cohorts.17 Similarly, we had predominant genotypes of LQT1 (10/59, 16.9%), LQT2 (12/59, 20.3%), and LQT3 (7/59, 11.9%). In a recent single-centre study of LQTS in China, LQT2 was also the most common genotype.18 We also identified five (8.5%) patients with rare CACNA1C (LQT8) mutations, all of whom were Hong Kong Chinese. Without a study of a large Chinese population in the past 5 years for cross reference, we cannot be certain whether LQT8 is more prevalent in Chinese than in other ethnic groups.
 
Long QT syndrome management and outcome
Beta blockers are the mainstay of treatment for all LQTS genotypes. In a registry of 1530 patients with LQTS, all beta blockers seemed equally effective in reducing risk of a first cardiac event after beta blocker initiation. For patients with LQT1, no single type of beta blocker has been found superior, although nadolol was found to be superior for patients with LQT2.19 However, another study suggested that symptomatic LQT1 and LQT2 patients on metoprolol had a higher rate of recurrence of cardiac events.20 In the present study, 21 patients were prescribed metoprolol, two of whom required switching to another beta blocker due to recurrent symptoms. Because of the relatively short follow-up duration and small number of patients in our cohort, it is impossible to conclude on the efficacy of each beta blocker for patients with each genotype. Genotype-guided therapy is advocated in contemporary management in LQTS. Based on the available evidence, we are inclined to use nadolol as our first choice in symptomatic LQT2 patients. In symptomatic LQT3 patients, dual therapy using beta blockers and mexiletine are used. Mexiletine is a sodium channel blocker shown to shorten QTc in LQT3 patients.21 22
 
In addition to medical therapy with beta blockers, treatment of LQTS can also include lifestyle modifications, sympathetic denervation, and device therapy. With a multi-modality management strategy and genotype-guided therapy, outcome of LQTS have improved markedly over the past decades. The event-free survival was 96% at 1 year, 93% at 5 years, and 90% at 10 years, as reported recently in a large single-centre study which included 83% asymptomatic probands.23 In the present study, the breakthrough cardiac event-free survival was 93.0% at 1 year, 80.7% at 5 years, and 72.6% at 10 years (1). The event rate in the present study is likely higher than that of the abovementioned study because we have a higher proportion of probands (85%), of whom 88% were symptomatic at presentation. Breakthrough cardiac events were mainly related to non-compliance to our treatment advice.
 
Study limitations
Our study was based on single-hospital data and referral bias is expected. We may have received referral of patients with LQTS with more severe symptoms. In addition, a short duration of follow-up in our patients (mean 5.3 years) may have led to underestimation of clinical cardiac events and mortality.
 
Future perspectives
Our study demonstrated the high yield of genetic testing and the importance of genetic information in predicting the prognosis of patients with LQTS and guiding their treatment. Early identification of affected family members through cascade screening of mutated gene was also demonstrated. We hope that public genetic services can continue to develop, to enable genetic testing to be offered to all patients with suspected channelopathies. We also advocate the establishment in Hong Kong of inherited arrhythmia clinics or cardiac genetic clinics in the public sector, as implemented in many other countries. Such clinics have proven effectiveness in reducing sudden cardiac death associated with inherited arrhythmia syndrome.24
 
Conclusion
Our study provides insight into the clinical and molecular profiles of young patients with LQTS in the only tertiary paediatric cardiology referral centre in Hong Kong. The LQT1, LQT2 and LQT3 genotypes are the most common in mutation-positive patients. Early identification of LQTS, administration of beta blocker therapy, device therapy, and lifestyle modifications can prevent sudden cardiac death. However, the breakthrough cardiac event survival was only 72.6% at 10 years. Further optimisation of the treatment strategy by genotype-guided therapy may reduce recurrent symptoms and improve prognosis.
 
Author contributions
Concept and design: APY Liu, BHY Chung, TC Yung.
Acquisition of data: SY Kwok, CYY Chan, TC Yung.
Analysis or interpretation of data: SY Kwok, CYY Chan, JLF Fung, CCY Mak.
Drafting of the article: SY Kwok, APY Liu.
Critical revision for important intellectual content: BHY Chung, KS Lun, TC Yung.
 
Acknowledgement
We would like to express our gratitude to all paediatricians and physicians who referred patients with LQTS to our department, and to the adult cardiologists who cared for our grown-up patients. We are also grateful for the contributions of the local university laboratories and the pathology departments of Hospital Authority hospitals in conducting genetic tests on some of our patients. We would like to express our gratitude to Ms Yo-yo WY Chu for her participation in providing genetic services to our patients.
 
Declaration
All authors have disclosed no conflicts of interest. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Results of this study were presented in the following meetings: (1) World Congress of Pediatric Cardiology & Cardiac Surgery 2017, Barcelona, Spain, 16-21 Jul 2017; (2) The 13th Congress of Asian Society for Pediatric Research 2017, Hong Kong, 6-8 Oct 2017; (3) The 26th Annual Scientific Congress, Hong Kong College of Cardiology 2018, Hong Kong, 15-17 Jun 2018. Abstract of this study was published in the Journal of the Hong Kong College of Cardiology (Kwok SY, Liu AP, Lun KS, et al. Clinical and genetic profile of congenital long QT syndrome in Hong Kong—18-year experience in pediatrics. J HK Coll Cardiol 2018;26:60).
 
Support/funding
The expenses of the genetic analysis used in our study were sponsored by the Children’s Heart Foundation of Hong Kong.
 
Ethical approval
This study received ethics approval from the Institutional Review Board of the University of Hong Kong/Hospital Authority Hong Kong Western Cluster.
 
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Branded versus generic drug use in chronic disease management in Hong Kong— perspectives of health care professionals and the general public

Hong Kong Med J 2018 Dec;24(6):554–60  |  Epub 3 Dec 2018
DOI: 10.12809/hkmj177087
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Branded versus generic drug use in chronic disease management in Hong Kong—perspectives of health care professionals and the general public
Vivian WY Lee, PharmD; Franco WT Cheng, BPharm, MCP; Felix YH Fong, BPharm; Enoch EN Ng, BA; Laadan LH Lo, BA; Livia YS Ngai, BPharm; Amy SM Lam, BPharm
School of Pharmacy, The Chinese University of Hong Kong, Shatin, Hong Kong
 
Corresponding author: Prof Vivian WY Lee (vivianlee@cuhk.edu.hk)
 
 Full paper in PDF
 
Abstract
Introduction: The aim of the present study was to evaluate the understanding of generic substitution among health care professionals and members of the general public (“general public”) in Hong Kong.
 
Methods: This cross-sectional descriptive study was performed by using a self-completed anonymous questionnaire from March 2015 to May 2017. The questionnaire included demographic data, knowledge of generic drugs, experiences of generic substitution, and views on policy.
 
Results: A total of 2106 general public, 73 doctors, 22 nurses, and 50 pharmacists responded the questionnaire. In all, 41.2% of the general public was aware that generic drugs have the same active ingredients. Although a majority of the health care professionals knew that generic drugs have the same active ingredients (doctors: 79.5%; nurses: 86.4%; pharmacists: 98.0%), many were unaware of bioequivalence (doctors: 37.0%; nurses: 18.2%; pharmacists: 50.0%). “Efficacy” was ranked as the primary concern among all groups; a substantial portion of respondents reported experiencing adverse drug reactions upon generic substitution (general public: 26.6%; doctors: 23.3%; nurses: 9.1%; pharmacists: 42.0%). At least half of the general public, nurses, and pharmacists considered that patients should be given a choice for generic substitution. However, fewer than one-fifth of doctors and nurses and approximately one-third of pharmacists considered that patient consent was needed prior to generic substitution, compared with approximately two-thirds of the general public.
 
Conclusion: The knowledge and perception of generic substitution remains low, both in the general public and among health care professionals. This knowledge deficit could potentially lead to different perspectives among stakeholders regarding generic substitution.
 
 
New knowledge added by this study
  • Knowledge and perception of generic substitution remains low, both in the general public and among health care professionals.
  • The general public, nurses, and pharmacists considered that patients should be given a choice for generic substitution.
  • Fewer than one-fifth of doctors and nurses and approximately one-third of pharmacists believed that patient consent was needed prior to generic substitution, compared with approximately two-thirds of the general public.
Implications for clinical practice or policy
  • Disagreements exist among stakeholders, although generic substitution is commonly employed in Hong Kong.
  • A number of patients reported adverse drug reactions upon generic substitution, which may be clinically significant. Further investigation is warranted.
 
 
Background
Health care expenditures have been escalating in recent years and have thus become a global challenge. Generic substitution is an important approach for lessening health care expenditures. The use of generic drugs allows patients to use the same active ingredients, dosage form, strength, and route of administration, with a similar efficacy and safety, as well as a lower price than that of the branded product.1 2 It is estimated that the use of generic drugs reduces the overall cost of health care in Europe by €100 billion annually.3
 
In Hong Kong, drug expenditures comprised 10% of the total expenditures of the Hospital Authority,4 a statutory body managing all public hospitals and institutions in Hong Kong, in 2015. In addition, drug expenditures increased markedly by 15.4% from 2013 to 2015.4 Because the public health care system is heavily subsidised by the government, cost containment of drug expenditures is vital in public hospitals. Therefore, it is not uncommon to adopt generic substitution in public hospitals, although it is not legally required in Hong Kong.
 
Generic substitution, either voluntary or mandatory, has been introduced in many countries around the world.5 6 However, patients and health care professionals remain sceptical regarding the use of generic drugs,6 7 8 9 10 11 12 despite the lack of evidence for significant clinical risks.13 14 15 In Hong Kong, medicines are typically supplied in clinics or hospitals, because prescribing and dispensing are not separated. As a result, the prescribing and dispensing of generic drugs relies on the attending physicians and internal policies established by public hospitals. There are few choices for members of the general public (“general public”). Furthermore, only stability data are required for the registration of pharmaceutical products in Hong Kong,16 while pharmacokinetic studies are generally required in many other countries, such as the United States and New Zealand.17 18 In 2009, a review committee recommended the inclusion of bioavailability and bioequivalence (BABE) studies as requirements for registration of generic drugs, as well as phased implementation of these new requirements. As of 2016, Phase 2 requirements for BABE studies were implemented; BABE studies are now mandatory for 29 antiepileptic drugs and 38 drugs with narrow therapeutic ranges.19 However, the suitability for most generic substitutions, especially in terms of the bioequivalence of the products, remains questionable. Owing to the lack of pharmacokinetic data, uncertainty may have greater impact in cases of generic-to-generic substitution. Generic-to-generic substitution due to manufacturer-related interruptions in drug distribution is common in Hong Kong.4
 
The present study aimed to evaluate the understanding of generic substitution among health care professionals and the general public, and to identify their experiences in terms of undesirable clinical outcomes after substitution. Methods
 
A cross-sectional descriptive study was conducted from March 2015 to May 2017 by using a selfcompleted anonymous questionnaire in Hong Kong. No consent was obtained because the questionnaire was conducted in an anonymous manner. The private information collected was considered non-sensitive and participants were informed that precautions would be taken to preserve the confidentiality of the research data. The background and aims of the questionnaire were disclosed to participants before they completed the questionnaire.
 
Two sets of questionnaires were developed for the general public and health care professionals, respectively. Both questionnaires cover four areas, including the demographic data of the interviewees (age, gender, monthly income, level of education, chronic diseases and insurance), knowledge and perception of generic drugs, experiences of generic substitution, and policy views for generic substitution. To ascertain the overall reliability of the results of the questionnaire, it was further modified in accordance with feedback from a pilot study that involved 50 physicians and 500 patients during January to February 2015.
 
Five statements, regarding active ingredient, dosage form, efficacy, similarity to branded drugs, price and quality, were used to assess knowledge regarding generic drugs in the general public; four separate statements, regarding active ingredient, strength, dosage form, and excipient, were used to assess knowledge among health care professionals. Health care professionals were further asked about the legal requirements for registration of generic drugs in Hong Kong, the definition of bioequivalence, and their perceptions of generic drugs. A 5-point Likert scale was used to assess perceptions of generic drugs with regard to price, side-effect profile, quality, efficacy, and preferences for using branded drugs.
 
In the third part of the questionnaires, experiences of using generic drugs were assessed. These included adverse drug reactions encountered after switching from branded to generic products, as well as factors that affected the use of generic drugs compared with branded drugs. The questionnaire for the general public further assessed previous usage of generic drugs, previous experience of switching from branded to generic, and the respondents’ willingness-to-pay for branded products. Respondents’ preferences regarding branded or generic products, with respect to changes in the price of branded products, were documented; the hypothetical price decreased from 200% of the generic price to equivalent to the price of generic products, in intervals of 20% reductions. Only respondents with chronic illnesses were included in this portion of the analysis, as this population is more sensitive to changes in drug price.
 
The last portion of the questionnaire assessed views regarding the need to obtain patients’ consent for substitution of branded products with generic products. The general public was further queried whether notification and explanation were required upon generic substitution.
 
The questionnaire for the general public was distributed during an outreach programme and public lecture series organised by the School of Pharmacy, The Chinese University of Hong Kong. Physicians from public sectors were recruited from the Prince of Wales Hospital; private physicians were randomly identified and recruited from the list of the Hong Kong Doctor Association, accessed via http://www.hkdoctors.org. Questionnaires were distributed via email to pharmacists and nurses who had participated in outreach programmes organised by the School of Pharmacy, The Chinese University of Hong Kong since 2010.
 
Discrete data were presented as frequency percentages; mean 5-point Likert scale ratings were used. Cumulative frequency was employed to determine the rank order of factors that affected the use of generic drugs. All data were analysed using Excel 2017 (Microsoft Corp., Redmond [WA], United States).
 
Results
A total of 5748 individuals were invited to complete the questionnaire, and 2251 complete responses were received. Tables 1 and 2 summarise the demographic data of the 2106 general public respondents, 73 doctor respondents, 22 nurse respondents, and 50 pharmacist respondents.
 

Table 1. Summary of respondents’ demographic data
 

Table 2. Summary of demographic data of general public respondents (n=2106)
 
Only 41.2% and 23.4% of the general public respondents were aware that generic drugs have the same active ingredients and dosage forms, respectively, as branded drugs. However, 65.5% of the respondents thought generic drugs were cheaper; only 14.9% believed that they were of lower quality. In contrast, the majority of the health care professionals were aware that generic drugs have the same active ingredients (doctors: 79.5%; nurses: 86.4%; pharmacists: 98.0%) and strength (doctors: 69.9%; nurses: 54.5%; pharmacists: 90.0%) as the branded product at a cheaper price (doctors: 74.0%; nurses: 54.5%; pharmacists: 98.0%). However, they were not aware of the definition of bioequivalence (doctors: 37.0%; nurses: 18.2%; pharmacists: 50.0%). Table 3 summarises the knowledge and perceptions of generic drugs among the different groups of respondents.
 

Table 3. Knowledge and perception of generic drugs
 
All four groups of respondents ranked “efficacy” as their primary concern when considering generic substitution. Other factors that were considered are detailed in Table 4. Moreover, a substantial number of respondents reported that they or their patients experienced adverse drug reactions upon generic substitution (general public: 26.6%; doctors: 23.3%; nurses: 9.1%; pharmacists: 42.0%), primarily comprising cardiovascular, gastrointestinal, psychiatric, and respiratory medications. The preferences of patients with chronic illnesses for branded products are illustrated in the Figure. Most respondents would opt for branded products as long as the price was not more than 1.4-times that of generic products.
 

Table 4. Experiences of using generic drugs
 
At least half of the general public (50.0%) and health care professionals (nurses: 63.6%; pharmacists: 92.0%), except doctors (42.5%), considered that patients should be given a choice for generic substitution. However, fewer than one-fifth of doctors and nurses, and approximately one-third of pharmacists, considered that patient consent was necessary prior to generic substitution, compared with approximately two-thirds of the general public. Views regarding policies of generic substitution among the different stakeholders are listed in Table 5.
 

Table 5. Views regarding policies for generic substitution
 
Discussion
A Japanese study showed that most patient respondents declined the use of generic drugs.6 In contrast to that report, the current study showed that 53.2% of the general public in Hong Kong was unaware whether they were using branded medications or generic substitutes. The proportion of awareness of “branded drugs” was also significantly lower in the current study than in the Japanese study (45.2% vs 68.4%).6 This difference could be attributed to the lower literacy in Hong Kong. More than 40% of respondents did not attend tertiary school or higher education, and more than 10% only completed primary school or lower. This low level of literacy may act as a barrier against effective communication when discussing the use of generic substitutes.
 
From our findings, generic substitution remains controversial in Hong Kong. Although most general public respondents believed that generic substitutes are not of lower quality, they demanded notification from health care professionals and wished to be given the option to consent to generic substitution; most health care professionals were reluctant to follow this approach. The reluctance may be attributed to the lack of understanding about generic drugs. Indeed, most doctors, nurses, and pharmacists tended to believe that generic drugs were less expensive because of their lower quality. Thus, it is unsurprising that the health care professionals exhibited a slight tendency to recommend branded products over generic substitutes (5-point Likert scale score = 3.1-3.3). Hence, education combined with more stringent registration requirements (eg, mandatory pharmacokinetic data) is essential for greater acceptance of generic drugs and maintenance of a sustainable health care system.
 
Despite being ranked as a primary concern regarding generic substitution, the efficacy of generic drugs cannot be guaranteed in Hong Kong due to a lack of pharmacokinetic data. Indeed, over 40% of the health care professional respondents stated that generic medications were of lower quality. Very recently, the Hong Kong government began to include BABE studies as legal requirements for the registration of certain generic drugs (eg, antiepileptic drugs and drugs with narrow therapeutic ranges), in addition to existing good manufacturing practice requirements.16 With the implementation of BABE requirements, this fundamental step may support increased quality of generic products, thus addressing the concerns of both the general public and health care professionals.20
 
Adverse drug reactions were also encountered upon generic substitution among various categories of commonly prescribed medications. Similar results have been reported in a Norway study, in which approximately one-third of patients reported negative experiences upon switching; there was no correlation between the adverse reaction and age, gender, or complexity of medical regimen.10 The lack of BABE studies could be a possible explanation, but further investigation is warranted.
 
Concerning preferences for branded products with respect to changes in price, it was surprising that not all respondents opted for branded products, even when the price was identical to that of generic products. Furthermore, the preference for branded products did not linearly increase with price. These results could be attributed to the design of the questionnaire and to the perceptions of the respondents, because the questionnaire did not specify the nature of the hypothetical medications that were substituted (eg, short-term or long-term administration), the equivalence of the products, or the actual price of the products. These factors may be significant to respondents when making a decision.
 
As indicated by the low response rate, selection bias is a major limitation of the current study due to its self-administered questionnaire nature and the convenient sampling method used to distribute the questionnaire. The unexpected high proportion of respondents with tertiary education or higher may be explained by an increased level of health consciousness among individuals who attend outreach services and public lectures organised by the university, as well as the complexity of the questionnaire. The survey results in this study potentially overestimated the knowledge of the general public with respect to generic drugs; thus, the generalisability of the results to the whole population may be limited. Further, as indicated from the demographic data, the sample size of health care professionals was relatively small and may not be representative of the overall population of health care professionals.
 
Conclusion
Although generic medications have been commonly used in Hong Kong, knowledge and perception of these medications has remained low, both in the general public and among health care professionals. This knowledge deficit could potentially lead to conflicting perspectives among stakeholders in terms of “generic substitution.”
 
Author contributions
Concept and design of study: VWY Lee.
Acquisition, analysis, and interpretation of data: FYH Fong,
EEN Ng, LLH Lo, LYS Ngai, ASM Lam.
Drafting of the article: FWT Cheng.
Critical revision of important intellectual content: VWY Lee, FWT Cheng.
 
Funding/support
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
Declaration
The authors have no conflicts of interest to disclose. The authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Ethical approval
This study was approved by the Survey and Behavioural Research Ethics of The Chinese University of Hong Kong and followed the Standards for Reporting Qualitative Research guidelines.
 
References
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2. King DR, Kanavos P. Encouraging the use of generic medicines: implications for transition economies. Croat Med J 2002;43:462-9.
3. Medicines for Europe. Our 5 pillars. Available from: http://www.medicinesforeurope.com/generic-medicines/our-5- pillars/. Accessed 25 Aug 2017.
4. Audit Commission, Hong Kong SAR Government. Report No. 67, Chapter 5, Hospital Authority’s Drug Management. 2016. Available from: http://www.aud.gov.hk/pdf_e/e67ch05.pdf. Accessed 3 Oct 2017.
5. Chong CP, March G, Clark A, Gilbert A, Hassali MA, Bahari MB. A nationwide study on generic medicines substitution practices of Australian community pharmacists and patient acceptance. Health Policy 2011;99:139-48. Crossref
6. Kobayashi E, Karigome H, Sakurada T, Satoh N, Ueda S. Patients’ attitudes towards generic drug substitution in Japan. Health Policy 2011;99:60-5. Crossref
7. Andersson K, Sonesson C, Petzold M, Carlsten A, Lönnroth K. What are the obstacles to generic substitution? An assessment of the behaviour of prescribers, patients and pharmacies during the first year of generic substitution in Sweden. Pharmacoepidemiol Drug Saf 2005;14:341-8. Crossref
8. Himmel W, Simmenroth-Nayda A, Niebling W, et al. What do primary care patients think about generic drugs? Int J Clin Pharmacol Ther 2005;43:472-9. Crossref
9. Iosifescu A, Halm EA, McGinn T, Siu AL, Federman AD. Beliefs about generic drugs among elderly adults in hospital-based primary care practices. Patient Educ Couns 2008;73:377-83. Crossref
10. Kjoenniksen I, Lindbaek M, Granas AG. Patients’ attitudes towards and experiences of generic drug substitution in Norway. Pharm World Sci 2006;28:284-9. Crossref
11. Babar ZU, Grover P, Stewart J, et al. Evaluating pharmacists’ views, knowledge, and perception regarding generic medicines in New Zealand. Res Social Adm Pharm 2011;7:294-305. Crossref
12. Rodríguez-Calvillo JA, Lana A, Cueto A, Markham WA, López ML. Psychosocial factors associated with the prescription of generic drugs. Health Policy 2011;101:178-84. Crossref
13. Privitera MD, Welty TE, Gidal BE, et al. Generic-to-generic lamotrigine switches in people with epilepsy: the randomised controlled EQUIGEN trial. Lancet Neurol 2016;15:365-72. Crossref
14. Ting TY, Jiang W, Lionberger R, et al. Generic lamotrigine versus brand-name Lamictal bioequivalence in patients with epilepsy: A field test of the FDA bioequivalence standard. Epilepsia 2015;56:1415-24. Crossref
15. Williamson IJ, Reid A, Monie RD, Fennerty AG, Rimmer EM. Generic inhaled salbutamol versus branded salbutamol. A randomised double-blind study. Postgrad Med J 1997;73:156-8. Crossref
16. Food and Health Bureau, Hong Kong SAR Government. Report of the Review Committee on Regulation of Pharmaceutical Products in Hong Kong. 2009. http://www.fhb.gov.hk/download/press_and_publications/otherinfo/100105_pharm_review/en_full_report.pdf. Accessed 25 Aug 2017.
17. Guidance for Industry. Bioavailability and Bioequivalence Studies for Orally Administered Drug Products—General Considerations. US Department of Health and Human Services, Food and Drug Administration, Center for Drug Evaluation and Research; 2003.
18. New Zealand Medicines and Medical Devices Safety Authority. New Zealand regulatory guidelines for medicines. Part A: when is an application for approval of a new or changed medicine required? 2014. Available from: http://www.medsafe.govt.nz/regulatory/Guideline/Full%20-%20NZ%20Regulatory%20Guidelines%20for%20 Medicines.pdf. Accessed 3 Oct 2017.
19. Pharmacy and Poisons Board Hong Kong. Implementation plan of Phase 2 requirement of bioavailability and bioequivalence studies for the registration of generic drugs. 2016. Available from: http://drugoffice.gov.hk/eps/upload/eps_news/26420/EN/1/Letter%20to%20Trade%20-%20Implementation%20Plan%20of%20Phase%202%20Requirement_v.5.pdf Accessed 25 Aug 2017.
20. Chua GN, Hassali MA, Shafie AA, Awaisu A. A survey exploring knowledge and perceptions of general practitioners towards the use of generic medicines in the northern state of Malaysia. Health Policy 2010;95:229-35. Crossref

Prehospital 12-lead electrocardiogram for patients with chest pain: a pilot study

Hong Kong Med J 2018 Oct;24(5):484–91  |  Epub 28 Sep 2018
DOI: 10.12809/hkmj177135
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Prehospital 12-lead electrocardiogram for patients with chest pain: a pilot study
KS Cheung, FHKCEM, MSc Cardiology1; LP Leung, FHKCEM2; YC Siu, FHKCEM3; TC Tsang, FHKCEM1; Matthew SH Tsui, FRCP (Edin), FHKAM (Emergency Medicine)1; CC Tam, FHKCP, FHKAM (Medicine)4; Raymond HW Chan, FHKAM (Medicine)5
1 Department of Accident and Emergency, Queen Mary Hospital, Pokfulam, Hong Kong
2 Emergency Medicine Unit, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
3 Medical Director, Fire and Ambulance Services Academy, Hong Kong Fire Services Department, Hong Kong
4 Department of Medicine, Queen Mary Hospital, Pokfulam, Hong Kong
5 Honorary Consultant Cardiologist, Hong Kong Sanatorium Hospital, Happy Valley, Hong Kong
 
Corresponding author: Dr KS Cheung (cks373@ha.org.hk)
 
 Full paper in PDF
 
Abstract
Introduction: After ST-segment elevation myocardial infarction (STEMI), it is vital to shorten reperfusion time. This study examined data from a pilot project to shorten the door-to-balloon (D2B) time by using prehospital 12-lead electrocardiogram (ECG).
 
Methods: Methods: Fifteen ambulances equipped with X Series® Monitor/Defibrillator (Zoll Medical Corporation) were deployed to the catchment area of Queen Mary Hospital, Hong Kong, from November 2015 to December 2016. For patients with chest pain, prehospital 12-lead ECG was performed and tele-transmitted to attending physicians at the accident and emergency department for immediate interpretation. The on-call cardiologist was called before patient arrival if STEMI was suspected. Data from this group of patients with STEMI were compared with data from patients with STEMI who were transported by ambulances without prehospital ECG or by self-arranged transport.
 
Results: From 841 patients with chest pain, 731 gave verbal consent and prehospital ECG was performed and transmitted. Of these, 25 patients with clinically diagnosed STEMI required emergency coronary angiogram with or without primary percutaneous coronary intervention. The mean D2B time for these 25 patients (93 minutes) was significantly shorter (P=0.003) than that for 58 patients with STEMI transported by ambulances without prehospital ECG (112 minutes) and that for 41 patients with STEMI with self-arranged transport (138 minutes). However, shorter reperfusion time was only recorded during daytime hours (08:00-17:59). No statistically significant difference in 30-day mortality was found.
 
Conclusion: Prehospital ECG is technologically feasible in Hong Kong and shortens the D2B time. However, shorter reperfusion time was only recorded during daytime hours.
 
 
New knowledge added by this study
  • This pilot study investigated the feasibility and performance of prehospital 12-lead electrocardiogram (ECG) deployed in ambulances in Hong Kong.
  • There was a statistically significant difference in door-to-balloon time when prehospital ECG was performed during daytime hours.
  • There was no statistically significant difference in 30-day mortality related to the use of prehospital ECG.
Implications for clinical practice or policy
  • Based on the evidence of feasibility and shortening of door-to-balloon time in Hong Kong, prehospital ECG services might be supported by the Hong Kong Fire Services Department.
  • Primary diversion of ST-elevation myocardial infarction may be implemented in Hong Kong in the future.
 
 
Introduction
In 1970, Nagel et al1 first reported the transmission of single-lead electrocardiogram (ECG) data via radio system to hospital physicians in Florida, US, for diagnostic purposes. To date, prehospital 12-lead ECG programmes have been implemented in various countries. In 2015, the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care recommended that prehospital 12-lead ECG should be acquired early for patients with possible acute coronary syndrome.2 The acquisition and tele-transmission of ECG data to the accident and emergency department (AED) allows rapid diagnosis of ST-segment elevation myocardial infarction (STEMI) by attending physicians. The on-call cardiologist and cardiac catheterisation laboratory (CCL) can then be notified early. This significantly shortens the door-to-balloon (D2B) time and improves patient outcome.3
 
The Hong Kong Fire Services Department (HKFSD) is the major emergency ambulance service provider in Hong Kong. Ambulances are deployed by the Fire Service Control Centre after calls to 999 and are manned by ambulance crew in accordance with pre-set protocols approved by the Medical Director of the HKFSD. Patients are transported to the nearest public hospital based on their geographical location. There is no choice with respect to the destination hospital, and there was no primary diversion for chest pain or STEMI in the project period.
 
Queen Mary Hospital (QMH) is a tertiary care hospital providing 24-hour emergency medical services in Hong Kong. Since November 2010, QMH has been the only public hospital in Hong Kong providing a 24-hour primary percutaneous coronary intervention (PPCI) service for all patients with STEMI.
 
In November 2015, the HKFSD and the QMH AED jointly launched a pilot project named ‘Prehospital Ambulance 12-Lead Electrocardiogram for Chest Pain Patients in Hong Kong West Cluster’. The present paper reports on the results of the first phase of that project. We hypothesised that prehospital ECG would shorten the D2B time and reduce mortality in patients with STEMI treated in AEDs in Hong Kong.
 
Methods
The present retrospective observational study analysed data from the ‘Prehospital Ambulance 12-Lead Electrocardiogram for Chest Pain Patients in Hong Kong West Cluster’ pilot project. That project began on 12 November 2015 and its first phase ended on 31 December 2016. All 122 ambulance crew members involved with the study received a half-day theory and hands-on training by clinical specialists of Zoll Medical Corporation (Chelmsford [MA], US) regarding the performance of prehospital 12-lead ECG. During the project period, there were 20 HKFSD ambulances operating in the catchment area of QMH; 10 were not operated during the night shift. Of these 20 ambulances, 15 were equipped with X Series® Monitor/Defibrillator (Zoll Medical Corporation) with ECG and tele-transmission functions. These 15 ambulances were deployed by the HKFSD to Aberdeen Ambulance Depot, Pok Fu Lam Ambulance Depot, Mount Davis Ambulance Depot, and Sheung Wan Fire Station.
 
In addition to the conventional management of chest pain or discomfort of cardiac origin, ambulance crews performed prehospital ECG (Fig). The ambulance crews were trained to use a standardised script in Chinese or English to explain the indication, procedure, benefit, and risk of performing prehospital ECG. Patients and accompanying relatives were provided with sufficient time for questions before informed consent was obtained. Patients were excluded if they were under 12 years of age; were in cardiac arrest; exhibited airway or breathing that could not be managed; had Glasgow Coma score ≤13; had first systolic blood pressure <90 mm Hg; had respiratory rate <10 or >29 breaths per minute; or were otherwise unable to consent.
 

Figure. Flowchart of prehospital ECG performance
 
The prehospital ECG was obtained in the ambulance compartment before its departure from the scene and was immediately tele-transmitted to the AED for interpretation by a physician. When a new prehospital ECG was transmitted, staff at the AED were notified via a dedicated laptop with alarm, fax, and email, as well as an alert phone call from the ambulance crew en route. The patient’s Hong Kong Identity Card number was also conveyed through the alert phone call from the ambulance. This allowed early identification of any new changes in the prehospital ECG, compared with previous ECG data stored in the hospital clinical management system record.
 
The most senior attending AED physician available was responsible for reading and interpreting the prehospital ECG. If the AED physician identified ST-segment elevation in two or more contiguous leads, the on-call cardiologist was paged and AED manpower and equipment were arranged immediately. Patients without such ST-segment elevation were triaged by experienced AED nurses upon arrival, in accordance with their overall clinical condition.
 
To compare the characteristics and outcomes of patients in this pilot project with those of other patients with chest pain (ie, those attending the AED by ambulance without prehospital ECG, or by self-arranged transport), data from the cardiac care unit of QMH were collected for comparison. Data of all patients attending the AED with emergency coronary angiography, with or without PPCI, were analysed. The D2B or door-to-catheter (D2C) time of different subgroups was determined and analysed as the primary outcome of this study. Secondary outcomes, including performance in daytime or night-time AED registration, triage accuracy, and 30-day mortality, were assessed in further subgroup analysis.
 
Results
From 12 November 2015 to 31 December 2016, ambulance crews equipped with X Series® attended to 841 patients presenting with cardiac chest pain. Verbal consent to perform prehospital ECG was obtained from 731 (86.9%) patients and these were included for analysis. A mean 1.76 prehospital ECGs were successfully performed and transmitted per day during the pilot project period. Reasons for not performing prehospital ECG are shown in Table 1.
 

Table 1. Reasons for lack of consent for prehospital ECG in the ambulance (n=110)
 
In total, 60% of patients were male. The patients’ mean age was 71 years, with a difference of 10 years between male (mean, 67 years) and female (mean, 77 years) patients. More patients registered at the AED during daytime hours (08:00-17:59; n=380 [52.0%]) than during night-time hours (18:00-07:59; n=351 [48.0%]). Most patients were triaged as category 3 in the AED (n=577) [78.9%]; those triaged as category 1 (critical), 2 (emergency), 4 (semi-urgent), and 5 (non-urgent) were 39 (5.3%), 57 (7.8%), 58 (7.9%), and 0, respectively.
 
In all, 93% of cases with cardiac chest pain were managed by AED physicians without further on-site consultation. Consultations with physicians from the cardiac care unit were initiated by the AED physician for 53 patients: 22 (41.5%) were performed on or before patient arrival at the AED, whereas the remaining 31 (58.5%) were conducted after patient arrival.
 
Of the 731 patients who received pre-hospital ECG, 534 (73.1%) patients were admitted to the medical ward, 96 (13.1%) to the emergency medical ward, 33 (4.5%) to the cardiac care unit, 13 (1.8%) to the surgical ward, three (0.4%) to the intensive care unit, and one (0.1%) to the neurosurgical ward for further management of their symptoms. Of the remaining patients, 39 (5.3%) were discharged from the AED, eight (1.1%) were discharged against medical advice, three (0.4%) disappeared, and one (0.1%) was certified in the AED.
 
Of the 731 patients who received pre-hospital ECG, 26 (3.6%) patients were clinically diagnosed with STEMI by AED physicians. Coronary angiogram, with or without PPCI, was arranged immediately for 25 of these patients. The remaining patient had a terminal malignancy and was offered non-invasive treatment after discussion with the patient’s family.
 
The mean D2B and D2C times were compared among 124 patients with clinically diagnosed STEMI: 25 patients with STEMI treated with prehospital ECGs; 58 patients with STEMI who were treated by ambulance crews without prehospital ECGs; and 41 self-transported patients with STEMI treated in the QMH AED during the pilot project period (Table 2). A statistically significant difference was found in the mean D2B time (P=0.003). Patients with prehospital ECGs had the shortest mean D2B (93 minutes) and D2C (71 minutes) times. Additionally, a greater percentage of patients with prehospital 12-lead ECG had D2B or D2C time ≤90 minutes.
 

Table 2. D2B and D2C times for patients in the ambulance (with and without prehospital ECG) and self-arranged transport groups (n=124)
 
Table 3 shows that there were significant differences in D2B or D2C times among the three groups of patients with STEMI attending the AED during daytime hours (08:00-17:59); there were no significant differences between the groups during night-time hours. The overall 30-day mortality of all patients with clinically diagnosed STEMI was 8% (10 of 124 patients) [Table 4]. Fisher’s exact test did not demonstrate any statistically significant difference between the intervention and control groups.
 

Table 3. Daytime and night-time D2B or D2C times for patients in the ambulance (with and without prehospital ECG) and self-arranged transport groups (n=124)
 

Table 4. Thirty-day mortality of patients admitted to the cardiac care unit from the accident and emergency department with emergency coronary angiogram with or without PPCI
 
When clinical diagnoses of STEMI were used as a standard to verify diagnoses made by the X Series® Monitor/Defibrillator diagnostic algorithm, there were 14 true positive, three false positive, 702 true negative, and 12 false negative cases. This corresponded to sensitivity (53.8%), specificity (99.6%), positive predictive value (82.4%), negative predictive value (98.3%), and accuracy (97.9%).
 
Discussion
Clinical diagnosis of ST-segment elevation myocardial infarction
In an AED without point-of-care cardiac biomarker testing capability, it is impossible to immediately detect a rise and/or fall in cardiac biomarkers, as described in the ‘Fourth universal definition of myocardial infarction’.4 Some patients in the AED with chest discomfort or other ischaemic symptoms, who developed ST elevation in two contiguous leads, were clinically diagnosed with STEMI before confirmation of typical biomarker changes, resulting in corresponding modification to medical management. This caused inaccuracy in calculation of the diagnostic performance of the diagnostic algorithm used in the X Series®, when the clinical diagnosis of STEMI in the AED was used as a standard for comparison.
 
Shortened door-to-balloon or door-to-catheter time during daytime hours
The theoretical benefits of prehospital 12-lead ECG included early diagnosis by AED physicians, early activation of the Acute Myocardial Infarction Clinical Pathway with cardiologist input, and activation of the CCL. It worked well during office hours, when the full team of interventional cardiologists, cardiac care nurses, and radiographers were on-site. The shortest D2B time was 41 minutes. However, during non-office hours or night-time hours, this team had to return from their homes for PPCI. This was the time-limiting factor during night-time hours and there was no statistically significant difference in night-time D2B or D2C time in our series for ambulance patients with or without prehospital 12-lead ECG. Possible solutions might be the provision of sufficient manpower for a 24-hour on-site interventional cardiology team. Other measures, such as cardiologists receiving prehospital 12-lead ECG data through their mobile phones, or activation of the CCL by emergency physicians (with an increased risk of inappropriate activation) could be considered.
 
Comparison with international standards for reperfusion
A greater percentage of patients with STEMI with prehospital 12-lead ECGs received reperfusion therapy with PPCI ≤90 minutes (Table 2). There was also a reduction in 30-day mortality to 0% in this subgroup (Table 4). However, whether a causeand- effect relationship existed is uncertain, due to our small sample size. Additionally, a statistically significant difference in 30-day mortality could not be demonstrated in our pilot project. Other cardiovascular outcome measurements, including re-infarction rate, major adverse cardiac events, and heart failure rate could be studied to provide insights regarding the benefit of prehospital 12-lead ECGs.
 
The D2B or D2C time could be improved through measures such as the performance of prehospital 12-lead ECGs on scene (rather than in-ambulance), or skipping AED consultation with direct cardiac care unit admission for patients suspected of STEMI on prehospital ECGs.5
 
Inappropriate activation and false positivity
Inappropriate activation of the CCL occurred when the interventional cardiologist provided an alternative diagnosis or considered the patient not to be a candidate for PPCI, with subsequent cancellation of the catheterisation procedure. In QMH, the CCL was activated by the on-call cardiologist, not the emergency physician, for appropriate patients with STEMI after on-site assessment. Therefore, inappropriate activation of the CCL by the emergency physician was 0% in our series. Instead, false positivity existed. False positivity was defined as patients with absence of thrombus causing obstruction in the culprit vessels and absence of a typical rise and fall of cardiac enzymes. In our pilot project, 17 of 124 patients with STEMI admitted through the AED had an emergency coronary angiogram performed without PPCI. Excluding one patient with triple vessel occlusion who failed PPCI and required emergent coronary artery bypass grafting, this yielded a false positive rate of 12.9% (16 of 124 patients). Prehospital 12-lead ECG extended the emergency assessment of patient condition to the prehospital phase. This allowed comparison of prehospital and AED ECGs. Dynamic ECG changes that occurred during the ambulance journey were more likely to be detected. Whether this might help to reduce the false positive activation of CCL or false negative discharge of patients from AED can be studied in the future.
 
Immediate electrocardiogram interpretation
In our pilot project, all ambulances equipped with X Series® Monitor/Defibrillator served the QMH catchment area without primary diversion. If primary diversion of patients with STEMI to a hospital with 24-hour PPCI service were to be implemented, on-scene ECG interpretation should be highly sensitive to avoid under-diversion. The ECG data could be interpreted by ambulance crews, machine diagnostic algorithm, or emergency physicians or cardiologists through tele-transmission. However, not all ambulance crews in Hong Kong are trained to interpret ECG data. Additionally, when compared with clinical diagnosis of STEMI in the AED, the sensitivity of the diagnostic algorithm used was 53.8% in our pilot project. Given this moderate sensitivity, immediate ECG interpretation by experienced emergency physicians or cardiologists is preferable. This diagnostic process is inevitably time-consuming. If ECG were performed on-scene instead of in the ambulance compartment, transport of the patient from scene to ambulance and the diagnostic process could happen simultaneously. Before ambulance departure from the scene, input from the emergency physician or cardiologist would be readily available to guide appropriate destination AED selection.
 
Reduction of under-triage in accident and emergency department
Triage by AED nurses must be both efficient and accurate, especially during busy periods. However, chest pain is a subjective perception, as are all types of pain. Before the availability of ECG, the vital signs and brief clinical contact between triage nurses and patients determined the assigned triage category for each patient. Because patients with STEMI belonged to category 1 (critical), it is inevitable that there would be increased under-triage of STEMI cases in the control group (Table 5). Prehospital ECG allowed more accurate triage of patients with STEMI.
 

Table 5. Distribution of triage categories in all STEMI cases
 
Overestimation of daytime door-to-balloon or door-to-catheter time
In total, 61.3% (76/124) [Table 3] of emergency coronary angiograms with or without PPCI were performed during daytime hours (08:00-17:59). However, this total includes patients who registered during non-office hours on Saturday, Sunday, and public holidays; during some of these, activation of the CCL involved the interventional cardiology team returning from home, as would be necessary during night-time hours. Because night-time D2B or D2C times were consistently longer than those recorded during daytime hours (Table 3), daytime D2B or D2C times were most likely overestimated. Studies have shown that in units with no significant difference in reperfusion time during daytime and night-time hours, the mortality of patients with STEMI was not influenced by whether patients presented during standard working hours or outside of these hours.6 Measures could be implemented to shorten the night-time D2B or D2C time for improved patient outcomes.
 
Thirty-day mortality
The Acute Myocardial Infarction Clinical Pathway was first established in QMH in 2007; by 2011, it successfully reduced the 30-day mortality rate of acute myocardial infarction from 18.4% to 14.9%.7 The mortality in our pilot project was 8.2% in the control group with conventional management (Table 4). This reduction of mortality in the control group was likely a combined result of advances in cardiovascular medications and diagnostic or therapeutic technologies, as well as improvement of patient health awareness in recent years. With implementation of prehospital 12-lead ECG, further reduction of mortality was expected. In our subgroup with prehospital 12-lead ECG and PPCI, 30-day mortality of 0% was recorded. However, a larger study over longer period of time is needed to establish whether there is a statistically significant clinical impact of prehospital 12-lead ECG on long-term mortality.
 
Mode of transport
Approximately one-third (41 of 124) of patients with AED diagnosis of STEMI arranged self-transport, rather than calling an ambulance. This underuse of the ambulance service is not unique to Hong Kong8 9 10and has been a well-documented cause of delayed hospital presentation8 10 and reperfusion time.10 In addition to the inability to perform prehospital ECG, patients with STEMI who self-transported to the AED were deprived of early assessment by the ambulance crew, administration of aspirin and/or sublingual nitrate, early notification of the AED for patients with unstable vitals, and immediate cardiopulmonary resuscitation (with defibrillation if necessary). Thus, wise use of the ambulance service should be advocated.
 
Incomplete coverage of the catchment area
According to the HKFSD, 88% of the QMH catchment area was covered by the 15 ambulances with X Series® Monitor/Defibrillator installed. Owing to this incomplete catchment area coverage, 48 ambulance patients did not receive prehospital ECG before PPCI. A greater benefit might be observed in the future, if all ambulances in the territory were capable of transmitting prehospital ECG, together with primary diversion of patients with STEMI.
 
Patient refusal
Consent to perform prehospital 12-lead ECG was not obtained from 110 of 841 (13.1%) patients with cardiac chest pain (71 female and 39 male patients). Refusal to consent may result in worse outcomes for patients with STEMI with delayed PPCI. Public education regarding the benefit of performing prehospital ECG may reduce refusal rates.
 
Referral from private physicians
Of 124 patients with STEMI attending the AED, 20 (16.1%) consulted private physicians before attendance to the AED; a number of ECGs performed in these private clinics or hospitals documented STEMI. However, apart from handwritten referral letters, there is currently no formal direct communication channel between private physicians and AED physicians. More convenient means of prehospital communication with or without teletransmission of prehospital 12-lead ECG performed in private clinics or hospitals could be explored. The benefits of seamless communication between private physicians and the AED are not limited to STEMI alone and may affect many other medical conditions.
 
Conclusion
Prehospital 12-lead ECG is technologically feasible in Hong Kong and shortens the D2B time. However, shorter reperfusion time was recorded only during daytime hours. Promotion of prehospital 12-lead ECG and proper utilisation of ambulance services for patients with cardiac chest pain may allow additional patients with STEMI to benefit from prehospital ECG.
 
Author contributions
Concept or design: All authors.
Acquisition of data: KS Cheung, YC Siu, RHW Chan.
Analysis or interpretation of data: KS Cheung, LP Leung.
Drafting of the article: KS Cheung.
Critical revision for important intellectual content: All authors.
 
Acknowledgement
We would like to thank the staff of the following institutions: Hong Kong Fire Services Department, for performing prehospital electrocardiograms and providing prehospital data; Division of Cardiology, Department of Medicine, Queen Mary Hospital, for providing data on door-to-balloon and door-to-catheter time; Department of Accident and Emergency, Queen Mary Hospital, for collecting patient clinical data; Emergency Medical Unit, LKS Faculty of Medicine, the University of Hong Kong, for statistical analyses; and Zoll Medical Corporation (269 Mill Rd, Chelmsford, MA 01824-4105, US), for providing the machines, training, and technical support free of charge.
 
Declaration
All authors have disclosed no conflicts of interest. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Funding/support
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
Ethical approval
Analysis of data from this pilot project was approved by the Institutional Review Board of the University of Hong Kong/ Hospital Authority Hong Kong West Cluster (UW17-318). Patient consent was waived.
 
References
1. Nagel EL, Hirshman JC, Nussenfeld SR, Rankin D, Lundblad E. Telemetry-medical command in coronary and other mobile emergency care systems. JAMA 1970;214:332-8. Crossref
2. O’Connor RE, Al Ali AS, Brady WJ, et al. Part 9: acute coronary syndromes: 2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 2015;132:S483-500. Crossref
3. Le May MR, Davies RF, Dionne R, et al. Comparison of early mortality of paramedic-diagnosed ST-segment elevation myocardial infarction with immediate transport to a designated primary percutaneous coronary intervention center to that of similar patients transported to the nearest hospital. Am J Cardiol 2006;98:1329-33. Crossref
4. Thygesen K, Alpert JS, Jaffe AS, et al. Fourth universal definition of myocardial infarction (2018). Eur Heart J 2018 Aug 25. Epub ahead of print. Crossref
5. Anderson LL, French WJ, Peng SA, et al. Direct transfer from the referring hospitals to the catheterization laboratory to minimize reperfusion delays for primary percutaneous coronary intervention: insights from the National Cardiovascular Data Registry. Circ Cardiovasc Interv 2015;8:e002477. Crossref
6. Cockburn J, Karimi K, Hoo S, et al. Outcomes by day and night for patients bypassing the emergency department presenting with ST-segment elevation myocardial infarction identified with a pre-hospital electrocardiogram. J Interv Cardiol 2015;28:24-31. Crossref
7. Wong KL, Wong YT, Yung SY, et al. A single centre retrospective cohort study to evaluate the association between implementation of an acute myocardial infarction clinical pathway and clinical outcomes. Int J Cardiol 2015;182:82-4. Crossref
8. Hong CC, Sultana P, Wong AS, Chan KP, Pek PP, Ong ME. Prehospital delay in patients presenting with acute ST-elevation myocardial infarction. Eur J Emerg Med 2011;18:268-71. Crossref
9. Song L, Yan HB, Yang JG, et al. Factors associated with use of emergency medical service for acute myocardial infarction in Beijing [in Chinese]. Zhonghua Yi Xue Za Zhi 2010;90:834-8.
10. Mathews R, Peterson ED, Li S, et al. Use of emergency medical service transport among patients with ST-segment-elevation myocardial infarction: findings from the National Cardiovascular Data Registry Acute Coronary Treatment Intervention Outcomes Network Registry—Get With The Guidelines. Circulation 2011;124:154-63. Crossref

Risk factors associated with 1-year mortality among patients with HIV-associated tuberculosis in areas with intermediate tuberculosis burden and low HIV prevalence

Hong Kong Med J 2018 Oct;24(5):473–83  |  Epub 28 Sep 2018
DOI: 10.12809/hkmj187303
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Risk factors associated with 1-year mortality among patients with HIV-associated tuberculosis in areas with intermediate tuberculosis burden and low HIV prevalence
CK Chan, FHKCP, FHKAM (Medicine)1; KH Wong, FHKCP, FHKAM (Medicine)2; MP Lee, FHKCP, FHKAM (Medicine)3; Kenny CW Chan, FHKCP, FHKAM (Medicine)4; CC Leung, FHKCP, FHKAM (Medicine)1; Eric CC Leung, FHKCP, FHKAM (Medicine)1; WK Chan, BNurs (Hons), MNurs4; Ida KY Mak, BSc, MPhil1
1 Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong
2 Head Office, Centre for Health Protection, Department of Health, Hong Kong
3 Department of Medicine, Queen Elizabeth Hospital, Hospital Authority, Hong Kong
4 Integrated Treatment Centre, Special Preventive Programme, Centre for Health Protection, Department of Health, Hong Kong
 
Corresponding author: Dr CK Chan (chikuen_chan@dh.gov.hk)
 
 Full paper in PDF
 
Abstract
Introduction: Data are limited regarding risk factors for mortality among patients with human immunodeficiency virus (HIV)-associated tuberculosis (TB) in areas with low HIV prevalence and intermediate TB burden, such as the Western Pacific region. This study aimed to assess such risk factors in Hong Kong, which has an intermediate TB burden and low HIV prevalence.
 
Methods: We conducted a retrospective cohort analysis of adult patients reported to the Hong Kong TB-HIV Registry between 2006 and 2015. Baseline characteristics were compared with Kaplan-Meier estimates. Cox proportional hazards regression modelling was used to identify factors associated with mortality.
 
Results: Of 299 patients studied, 21 (7.0%) died within 12 months of anti-TB treatment (median [interquartile range], 7.5 [3.8-10] months). The median age of death was 54 (interquartile range, 40.5-75.0) years. The cause of death was TB in five and unrelated to TB in the remaining 16. Cox proportional hazards regression showed that older age (adjusted hazard ratio=4.5; 95% confidence interval [CI]=1.4-14.9), history of drug addiction (4.6; 95% CI=1.6-13.0), and low baseline CD4 cell count of <50/μL (2.9; 95% CI=1.1-7.7) were independent risk factors for death within 12 months.
 
Conclusion: This study complements previous studies by providing information regarding risk factors associated with mortality among patients with HIV-associated TB in areas with intermediate TB burden and low HIV prevalence. The results from our study may guide targeted measures to improve survival in other areas with intermediate TB burden and low HIV prevalence, such as the Western Pacific region.
 
 
New knowledge added by this study
  • Previous studies on risk factors associated with mortality among patients with human immunodeficiency virus (HIV)–associated tuberculosis (TB) have mainly examined patients from developing countries with high TB burden and high HIV prevalence, especially from Africa.
  • The present study showed that older age, a history of drug addiction, and a low baseline CD4 cell count of <50/μL were independent risk factors for death within 12 months in an area with intermediate TB burden, low HIV prevalence, and good infrastructure.
Implications for clinical practice or policy
  • This study might facilitate formulation of innovative strategies to improve health outcomes among patients with HIV-associated TB in areas with intermediate TB burden and low HIV prevalence.
 
 
Introduction
In 2016, there were an estimated 10.4 million new tuberculosis (TB) cases worldwide, of which 1.03 million (10%) were among people living with human immunodeficiency virus (HIV).1 Of the estimated 1.7 million deaths resulting from TB disease, 0.4 million were among people living with HIV.1 The success rate of TB treatment is generally worse for patients with HIV than for those without. Globally, the proportion of patients with TB who died during treatment has been reported as approximately three-fold higher among patients with HIV than those without (11% vs 4%); this difference is greatest in the Western Pacific region (13% vs 2%).1
 
Identification of risk factors associated with mortality and innovative strategies to manage disease in high-risk groups may contribute to reduction in mortality among patients coinfected with TB and HIV. Lack of drug susceptibility testing, suboptimal initial anti-TB treatment, disseminated TB, and a low CD4 cell count have been reported as prognostic factors for increased TB-related mortality in Eastern Europe.2 3 In some areas of Africa with high HIV prevalence, increased odds of mortality are associated with the following factors: advanced age, pretreatment sputum smear status, history of TB, and lack of antiretroviral therapy (ART).4 5 6 However, data regarding risk factors for mortality in the Western Pacific region are scarce.7 8 In particular, there have been few assessments in areas with intermediate burden of TB in the Western Pacific region.
 
Hong Kong has been classified by the World Health Organization as a place with intermediate TB burden and good infrastructure. The TB notification rate in Hong Kong was 60.5 per 100 000 population in 2015, of which 40.2% were patients aged >65 years.9 The overall TB mortality rate was 2.3 per 100 000 population in the same year. The prevalence of HIV infection in the general population in Hong Kong is low (<0.1%).10 Notably, patients with HIV-associated TB constituted approximately 1% of all TB notifications in Hong Kong.9 Treatment outcomes of a cohort of patients reported to the territory-wide TB-HIV Registry of the Hong Kong Department of Health, as of 31 December 2009, have been reported previously.11 The aim of the present study was to assess the 1-year mortality rate among patients with HIV-associated TB and to identify risk factors associated with mortality. Therefore, we retrospectively reviewed the data of patients reported to the TB-HIV Registry between 1 January 2006 and 31 December 2015. The results of this study are expected to guide targeted measures to improve survival and to inform TB control policies in areas with intermediate TB burden, such in Hong Kong and throughout the Western Pacific region.
 
Methods
Data regarding sex, age, ethnicity, case category, history of drug addiction, site of TB infection, sputum smear and culture results, CD4 cell count at TB diagnosis, and ART usage of consecutive patients reported to the TB-HIV Registry between 1 January 2006 and 31 December 2015 were retrieved and retrospectively reviewed. Tuberculosis treatment outcomes at 12 months after initiation of treatment, and mortality data such as the date and cause(s) of death, were obtained from the database. Further mortality data were obtained by cross-matching with the statutory death registry by using patients’ identity card numbers/passport numbers as unique identifiers. For patients who died within 12 months during anti-TB treatment, relevant clinical records from chest clinics and hospitals were traced and reviewed.
 
All the data collected were imported into Epi-Info software, and exported into SPSS (Windows version 16.0; SPSS Inc, Chicago [IL], US) for analysis. For the identification of variables potentially associated with mortality, comparisons of survival status were made by using Kaplan-Meier estimates. A two-tailed P value <0.05 was considered statistically significant. An evaluation of the effects of covariates on mortality was performed by using Cox proportional hazards regression modelling. Variables that were significant in the univariate analysis or were of clinical significance were included in the model. Patients who had been transferred out of Hong Kong before completion of treatment were censored at the date they were last known to be alive, based on the date of their most recent contact. For patients who were lost to follow-up, but were not deceased according to the statutory death registry, the censor date was 12 months. Kaplan-Meier survival curves were generated to demonstrate differences in mortality, stratified for a variety of covariates.
 
Results
Of 337 patients reported to the TB-HIV Registry between 2006 and 2015, 17 were excluded either because of duplicate reporting or revision of diagnosis. Twenty-one patients were tourists or illegal immigrants with a very short stay in Hong Kong; these were also excluded, resulting in 299 patients in the analysis. Baseline demographic and clinical characteristics of these 299 patients, stratified by survival status at 12 months from the date of start of anti-TB treatment, are shown in Table 1. Overall, extrapulmonary TB was common, present in approximately 65% of patients. Sputum smear positivity was present in more than one-third of patients. Of note, the multidrug resistance rate among the bacteriologically proven cases was low (2.2% overall). The overall median CD4 cell count at the time of TB diagnosis was 100/μL (interquartile range [IQR], 36-204/μL). Of 284 patients who were alive and had not defaulted or transferred out at 8 weeks from the initiation of TB treatment, 73 (25.7%) were undergoing ART. The proportion undergoing ART at 8 weeks was higher among patients reported to the TB-HIV Registry between 2011 and 2015 than among those reported between 2006 and 2010 (37.3% vs 18.4%; P=0.0005).
 

Table 1. Demographic and clinical characteristics of patients reported to the Hong Kong TB-HIV Registry between 2006 and 2015, stratified by survival status at 12 months from the start of anti-TB treatment
 
Overall, 135 (45.2%) were cured or had completed treatment at 12 months, whereas 96 (32.1%) remained on an anti-TB treatment regimen at 12 months due to extensive disease, use of a non-standard treatment regimen, and/or drug resistance. Twenty-three (7.7%) patients defaulted treatment for more than 2 months, while 24 (8.0%) patients were transferred out; 21 (7.0%) patients died within 12 months of the initiation of anti-TB treatment. The proportions of patients who died within 12 months among patients reported to the TB-HIV Registry between 2011 and 2015 and those reported between 2006 and 2010 were similar (7.1% vs 6.9%). The median time interval between the initiation of anti-TB treatment and death was 7.5 months (IQR, 3.8-10 months); the median age of death was 54 (IQR, 40.5-75.0) years. The cause of death was due to TB in five patients and unrelated to TB in the remaining 16 (Table 2). A similar proportion of patients with early death within 2 months died from TB (25.0%), compared with those who died after 2 months (23.5%; P=0.72).
 

Table 2. Characteristics, causes, and timing of death of patients with HIV-associated TB who died within 12 months from initiation of anti-TB treatment (n=21)
 
Table 3 summarises the results of univariate (using Kaplan-Meier estimates) and Cox proportional hazards regression analysis with respect to 1-year mortality of the 299 cases. In the univariate analysis, older age, case categories other than new cases, a positive sputum smear, a history of drug addiction, and a low CD4 cell count (<50/μL) at the time of TB diagnosis were associated with mortality. Further analysis with Cox proportional hazards regression showed that older age (adjusted hazard ratio=4.5; 95% confidence interval [CI]=1.4-14.9; P=0.012), a history of drug addiction (adjusted hazard ratio=4.6; 95% CI=1.6-13.0; P=0.005) and a low CD4 cell count (<50/μL) at the time of TB diagnosis (adjusted hazard ratio=2.9; 95% CI=1.1-7.7; P=0.03) remained the sole independent risk factors for death within 12 months. Similar findings were observed when ART at 8 weeks was included in the Cox proportional hazards regression model (results not shown). Unadjusted Kaplan-Meier survival curves stratified by covariates are shown in the Figure.
 

Table 3. Survival status at 12 months of 299 patients with HIV-associated TB and comparison by univariate and Cox proportional hazards regression modelling
 

Figure. Kaplan-Meier survival curves of patients with HIVassociated TB at 12 months, stratified for (a) age-group, (b) history of drug addiction, and (c) baseline CD4 cell count
 
Discussion
This retrospective cohort study was designed to examine the mortality pattern and factors associated with 1-year mortality among patients with HIV-associated TB reported to the Hong Kong TB-HIV Registry. In our cohort, 7.0% died within 12 months of anti-TB treatment (median [IQR], 7.5 months [3.8-10 months]). The median age of death was 54 (IQR, 40.5-75.0) years. The cause of death was unrelated to TB in >75% of the cohort. Older age, history of drug addiction, and a low CD4 cell count (<50/μL) at the time of TB diagnosis were independent risk factors for death within 12 months.
 
The 1-year mortality rate of 7.0% among patients with HIV-associated TB in our cohort was lower than the rates in Eastern Europe (29%) and Latin America (11%) reported in a study by Podlekareva et al.2 The mortality rate in our study was also lower than the rates reported in other countries in the Western Pacific region, such as Thailand (17%)7 and Cambodia (22.5%)8 among enrolled patients with HIV-associated TB. Nonetheless, the rate was higher than the 4% reported for Western Europe.2 Although these rates might not be directly comparable because of differences in the study periods and methodologies used, the results from our study add important data to the current body of literature regarding mortality risk among patients with HIV-associated TB in the Western Pacific region.
 
In our cohort, 76.2% of deaths were unrelated to TB. This differed from the proportion reported among patients with HIV-associated TB in Eastern Europe; TB was reported as the cause of death in >60% of those who died.2 Differences in patient profile, degree of immunosuppression, proportion of patients receiving ART, and proportion of patients with other opportunistic infections might have contributed to the differences observed with respect to the cause(s) of death.
 
The proportion of patients who died within the first 2 months of anti-TB treatment due to TB was similar to that among patients who died after 2 months (25.0% vs 23.5%). This finding differed from the outcome of a prospective observational study that examined the causes of death among patients with HIV-associated TB in Thailand: 18 of 33 deaths (55%) within 60 days after initiation of TB treatment were caused by TB, compared with 11 of 41 deaths (27%) beyond 60 days after initiation of TB treatment (P=0.02).7 However, the patients in that study exhibited a greater degree of immunosuppression: the median CD4 count for patients in that study was 55/μL (IQR, 18-142/μL), compared with a median CD4 count of 100/μL (IQR, 36-204/μL) in our cohort.
 
The finding that older age constitutes a risk factor for mortality in our cohort is consistent with findings in some other studies.4 5 12 In a recently reported retrospective 10-year electronic record review of patients with TB in a South African province, although the large majority of patients with TB that died were aged 18 to 49 years, the odds of dying were incrementally higher in older age-groups: 8 to 17 years (adjusted odds ratio [AOR]=2.0; 95% CI=1.5-2.7), 18 to 49 years (AOR=5.8; 95% CI=4.0-8.4), 50 to 64 years (AOR=7.7; 95% CI=4.6-12.7), and ≥65 years (AOR=14.4; 95% CI=10.3-20.2).4 A similar finding was observed in another South African study.5 In our cohort, the median age of death was 54 years. Patients aged ≥65 years had an adjusted hazard ratio of 4.5 for dying, compared with younger patients. Atypical presentation, increased comorbidity, and a higher proportion of drug-related adverse events might have contributed to the increased odds of death in the older age-group.
 
In our cohort, a history of drug addiction was significantly associated with death at 12 months (adjusted hazard ratio=4.6; 95% CI=1.6-13.0). In the study by The TB:HIV Study Writing Group, injection drug use was reported as a significant predictor of death (hazard ratio=2.11; 95% CI=1.04-4.26); notably, this became non-significant after adjustment due to high correlation with the region of residence.3 The association between a history of drug abuse and mortality in our cohort—also reported in some other studies—is not surprising. Poor access to and uptake of health services, poor adherence, and treatment default are well-known to pose unique challenges for treatment of drug users.13 In a study of 291 patients with smear- and culture-positive pulmonary TB presenting for retreatment in Morocco, substance users were 2.7 times more likely to default treatment, compared with non-substance users (AOR=2.73; 95% CI=1.04-7.15).14 Because injection drug users exhibit a high prevalence of chronic viral hepatitis and alcohol abuse, hepatotoxic reactions to anti-TB drugs may be more common.15 In a study that examined the role of hepatitis C virus and HIV in anti-TB drug-induced hepatotoxicity, Ungo et al16 found that patients with TB exhibited a four-to-five-fold increased risk of drug-induced hepatitis if coinfected with viral hepatitis or HIV; moreover, they exhibited a 14-fold increased risk if coinfected with both. In addition, efavirenz, nevirapine, and rifampicin may increase methadone clearance, thus causing methadone withdrawal; this may dissuade drug users from continuing treatment.15
 
In a study that examined TB-related mortality in people living with HIV in Eastern Europe and Latin America, a CD4 cell count of <50/μL was associated with increased TB-related mortality (hazard ratio=3.46; 95% CI=2.02-5.95; P<0.0001) after adjustment for multidrug-resistant TB status.2 In another study conducted in Ethiopia, a CD4 cell count of <75/μL was also associated with increased mortality (adjusted hazard ratio=4.83; 95% CI=1.98-11.77).6 In our cohort, consistent with the findings from prior studies, patients with HIV-associated TB with a low CD4 cell count (<50/μL) at the time of TB diagnosis had an adjusted hazard ratio of 2.9 (95% CI=1.1-7.7; P=0.03) for mortality at 1 year. The findings from our study and other studies support the recommendation that ART be initiated early during TB treatment in patients with HIV.
 
Case category other than new cases was associated with increased mortality at 12 months in univariate analysis in our study. However, the association disappeared in the adjusted model. Of note, prior history of TB or retreatment has been associated with increased mortality in some other studies.5 17 Because our study was a retrospective case review, it is uncertain whether misclassification or inadequate control for other unknown confounding factors might have obscured an association between case category and mortality.
 
Studies regarding the association between sputum smear status and death have reported conflicting results. In a retrospective cohort study of predictors of TB mortality in Khayelitsha, South Africa, an area with high HIV prevalence, no association was found between smear status and death.5 Similarly, in a study of patients coinfected with TB and HIV at a teaching hospital in Ghana, no differences were reported in clinical outcome between patients with smear-negative TB status and those with smear-positive TB status.18 In a prospective study of 827 adult TB in-patients registered at Zomba Hospital, Malawi, of whom 77% were HIV-seropositive, patients with smear-negative pulmonary TB exhibited the highest death rates during 32 months of follow-up (hazard ratio=2.7; 95% CI=2.1-3.5; P<0.001, compared to smear-positive patients).19 Similar findings were reported in studies of patients with HIV-associated TB in South Africa and in Cameroon.17 20 Conversely, in a study that examined patients with HIV with culture-confirmed pulmonary TB in the US from 1993 to 2006, patients with smear-negative TB exhibited better survival than patients with smear-positive disease, both before (hazard ratio=0.82; 95% CI=0.75-0.90) and after (hazard ratio=0.81; 95% CI=0.71-0.92) the introduction of combination ART.21 In our study, a positive sputum smear was associated with mortality in univariate analysis, but not in multivariate analysis. The results from our study regarding the effect of AFB smear status on survival were similar to those from the study in the US. The reasons for observed differences in survival among patients with HIV with sputum smear-negative TB between resource-rich and resource-limited settings are likely complex; these might have been a result of differences in study populations, the availability of diagnostics, misdiagnosis, or differences in treatment regimens.21
 
Of note, ART was not a prognostic factor for mortality in our study, either for the entire cohort or when the analysis was restricted to the subgroup with a CD4 cell count of <50/μL (results for the latter not shown). In addition, the mortality rate among patients in the later cohort (2011 to 2015) remained similar compared to the earlier cohort (2006 to 2010), although the proportion of patients receiving ART at 8 weeks had doubled. This conflicts with the finding that ART reduces mortality, reported in some other studies.3 5 The failure of ART to affect mortality in our study might have been because ART was selectively initiated for patients with more advanced HIV-associated TB (ie, by attending physicians) during the study period. High age-related mortality in the cohort, as discussed above, and inadequate control for other confounding factors might have masked the protective effect of ART.
 
The strength of this study is that it included a relatively complete set of data regarding clinical features of all patients, as well as the cause(s) and timing of death among patients who died. Such data have been less frequently reported in previous studies. The primary limitation is that it was a retrospective study conducted under programme conditions. Our risk factor evaluation was limited by the availability of data present in the database of the TB-HIV Registry and in clinical records. Information regarding case categories, drug addiction, and CD4 cell count was unavailable for a small subset of patients. Classifying patients with missing case category information as new cases and those with missing substance use data as non-users might have biased our analyses of these risk factors such that no significant differences were found. The time lag between HIV diagnosis and initiation of ART could not be determined because information regarding the date of HIV diagnosis was missing for some patients in the earlier portion of the study period, as well as for patients who were diagnosed outside Hong Kong. Furthermore, information regarding the time lag between presentation of patients to the health care system and the initiation of anti-TB treatment was not captured in the TB-HIV Registry. Therefore, the potential effect of such delay in the initiation of anti-TB treatment on mortality could not be examined. Another limitation is that the accuracy of the data in the programme record forms (on which the database was constructed) and death certificates for coding TB as the underlying cause of death was unknown. Nonetheless, for those patients who died, relevant clinical records from chest clinics and hospitals were traced for review. Misclassification regarding the cause(s) of death should be minimal. Finally, the small number of patients who died, limited statistical power, and inadequate controls for other unknown confounding factors may have concealed the effects of significant variables, as discussed above.
 
Notwithstanding the aforementioned limitations, we demonstrated that older age, history of drug addiction, and low CD4 cell count (<50/μL) at TB diagnosis were independent risk factors for death within 12 months. This study complements previous studies by providing information regarding risk factors associated with mortality among patients with HIV-associated TB in an area in the Western Pacific region with intermediate TB burden and low HIV prevalence. The results from our study may have important implications for health care programmes; they may aid in formulating innovative strategies and new guidelines to guide targeted measures for the management of disease among subgroups of patients at risk of death from TB or HIV during the course of anti-TB treatment. As such, they may help optimise TB and HIV management in the Western Pacific region.
 
Author contributions
Concept or design of study: CK Chan, ECC Leung, CC Leung, KH Wong.
Acquisition of data: CK Chan, IKY Mak, WK Chan, KCW Chan, MP Lee.
Analysis or interpretation of data: ECC Leung, CC Leung, CK Chan, MP Lee, KCW Chan, IKY Mak.
Drafting of the article: CK Chan, ECC Leung.
Critical revision for important intellectual content: All authors.
 
Acknowledgement
The authors would like to thank Dr CM Tam, previous Consultant Chest Physician in-charge of Tuberculosis and Chest Service, Centre for Health Protection, Department of Health of Hong Kong, for his contributions to the conception and design of this work, as well as his valuable comments on the early draft of this article.
 
Declaration
All authors have disclosed no conflicts of interest. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity. The findings of this study were presented in part at the 13th Hong Kong, Macau, Taiwan, Shanghai and Guangdong Tuberculosis Conference, Hong Kong, 2 November 2017.
 
Funding/support
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
Ethical approval
This study was approved by the Ethics Committee of the Department of Health of Hong Kong.
 
References
1. World Health Organization. Global Tuberculosis Report 2017. Geneva: World Health Organization; 2017.
2. Podlekareva DN, Efsen AM, Schultze A, et al. Tuberculosis-related mortality in people living with HIV in Europe and Latin America: an international cohort study. Lancet HIV 2016;3:e120-31. Crossref
3. TB:HIV Study Writing Group. One-year mortality of HIV-positive patients treated for rifampicin- and isoniazid-susceptible tuberculosis in Eastern Europe, Western Europe, and Latin America. AIDS 2017;31:375-84. Crossref
4. Heunis JC, Kigozi NG, Chikobvu P, Botha S, van Rensburg HD. Risk factors for mortality in TB patients: a 10-year electronic record review in a South African province. BMC Public Health 2017;17:38. Crossref
5. Pepper DJ, Schomaker M, Wilkinson RJ, de Azevedo V, Maartens G. Independent predictors of tuberculosis mortality in a high HIV prevalence setting: a retrospective cohort study. AIDS Res Ther 2015;12:35. Crossref
6. Sileshi B, Deyessa N, Girma B, Melese M, Suarez P. Predictors of mortality among TB-HIV co-infected patients being treated for tuberculosis in Northwest Ethiopia: a retrospective cohort study. BMC Infect Dis 2013;13:297. Crossref
7. Cain KP, Anekthananon T, Burapat C, et al. Causes of death in HIV-infected persons who have tuberculosis, Thailand. Emerg Infect Dis 2009;15:258-64. Crossref
8. Marcy O, Laureillard D, Madec Y, et al. Causes and determinants of mortality in HIV-infected adults with tuberculosis: an analysis from the CAMELIA ANRS 1295-CIPRA KH001 randomized trial. Clin Infect Dis 2014;59:435-45. Crossref
9. Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong SAR Government. Annual Report 2015. Available from: http://www.info.gov.hk/tb_chest/doc/Annual_Report_2015.pdf. Accessed 18 Sep 2018.
10. Special Preventive Programme, Centre for Health Protection, Department of Health, Hong Kong SAR Government. HIV surveillance report-2015 update. Available from: http://www.info.gov.hk/aids/english/surveillance/sur_report/hiv15.pdf. Accessed 18 Sep 2018.
11. Chan CK, Wong KH, Leung CC, et al. Treatment outcomes after early initiation of antiretroviral therapy for human immunodeficiency virus-associated tuberculosis. Hong Kong Med J 2013;19:474-83. Crossref
12. Waitt CJ, Squire SB. A systematic review of risk factors for death in adults during and after tuberculosis treatment. Int J Tuberc Lung Dis 2011;15:871-85. Crossref
13. Deiss RG, Rodwell TC, Garfein RS. Tuberculosis and illicit drug use: review and update. Clin Infect Dis 2009;48:72-82. Crossref
14. Dooley KE, Lahlou O, Ghali I, et al. Risk factors for tuberculosis treatment failure, default, or relapse and outcomes of retreatment in Morocco. BMC Public Health 2011;11:140. Crossref
15. World Health Organization. Integrating collaborative TB and HIV services within a comprehensive package of care for people who inject drugs. Geneva: World Health Organization; 2016.
16. Ungo JR, Jones D, Ashkin D, et al. Antituberculosis drug-induced hepatotoxicity. The role of hepatitis C virus and the human immunodeficiency virus. Am J Respir Crit Care Med 1998;157:1871-6. Crossref
17. Mabunda TE, Ramalivhana NJ, Dambisya YM. Mortality associated with tuberculosis/HIV co-infection among patients on TB treatment in the Limpopo province, South Africa. Afr Health Sci 2014;14:849-54. Crossref
18. Mudd J, Jaramillo L, Kwara E, et al. Impact of smear-negative results on tuberculosis outcome in HIV co-infected patients at a teaching hospital in Ghana. Ann Glob Health 2016;82:516.
19. Kang’ombe C, Harries AD, Banda H, et al. High mortality rates in tuberculosis patients in Zomba Hospital, Malawi, during 32 months of follow-up. Trans R Soc Trop Med Hyg 2000;94:305-9. Crossref
20. Djouma FN, Noubom M, Ngomba AV, Donfack H, Kouomboua PS, Saah MA. Determinants of death among tuberculosis patients in a semi urban diagnostic and treatment centre of Bafoussam, West Cameroon: a retrospective case-control study. Pan Afr Med J 2015;22:253. Crossref
21. Cavanaugh JS, Shah NS, Cain KP, Winston CA. Survival among patients with HIV infection and smear-negative pulmonary tuberculosis–United States, 1993-2006. PLoS One 2012;7:e47855. Crossref

Depression and anxiety among university students in Hong Kong

Hong Kong Med J 2018 Oct;24(5):466–72  |  Epub 24 Sep 2018
DOI: 10.12809/hkmj176915
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Depression and anxiety among university students in Hong Kong
Kevin WC Lun, CK Chan, Patricia KY Ip, Samantha YK Ma, WW Tsai, CS Wong, Christie HT Wong, TW Wong, D Yan
Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
 
Corresponding author: Mr Kevin WC Lun (lunkwc@gmail.com)
 
 Full paper in PDF
 
Abstract
Introduction: Entry into tertiary education is a critical juncture where adolescents proceed to adulthood. This study aimed to determine the prevalence of depression and anxiety, and factors associated with such symptoms, among university undergraduate students in Hong Kong.
 
Methods: A cross-sectional questionnaire study was employed. A total of 1200 undergraduate students from eight University Grants Committee–funded universities were invited to complete three sets of questionnaires, including the 9-item patient health questionnaire for screening of depressive symptoms, the 7-item generalised anxiety disorder scale for screening of anxiety symptoms, and a socio-demographic questionnaire.
 
Results: Among the valid responses (n=1119) analysed, 767 (68.5%) respondents indicated mild to severe depressive symptoms, which were associated with mild to severe anxiety symptoms. Several lifestyle and psychosocial variables, including regular exercise, self-confidence, satisfaction with academic performance, and optimism towards the future were inversely related with mild to severe depressive symptoms. A total of 599 (54.4%) respondents indicated mild to severe anxiety symptoms, which were associated with level of academic difficulty. Satisfaction with friendship, sleep quality, and self-confidence were inversely associated with mild to severe anxiety symptoms.
 
Conclusion: More than 50% of respondents expressed some degree of depressive and anxiety symptoms (68.5% and 54.4%, respectively). Approximately 9% of respondents exhibited moderately severe to severe depressive symptoms; 5.8% exhibited severe anxiety symptoms. Respondents reporting regular exercise, higher self-confidence, and better satisfaction with both friendship and academic performance had fewer depressive and anxiety symptoms.
 
 
New knowledge added by this study
  • Up to 9% of university students in Hong Kong exhibit moderately severe to severe depressive symptoms.
  • Up to 5.8% of university students in Hong Kong exhibit severe anxiety symptoms.
  • Respondents reporting regular exercise, higher self-confidence, and better satisfaction with both friendship and academic performance had fewer depressive and anxiety symptoms.
Implications for clinical practice or policy
  • Health care workers and organisations such as universities should be aware of potential depression and anxiety among university undergraduate students.
  • Adolescents and young adults in Hong Kong should be educated, to raise social awareness of depression and anxiety among university undergraduate students.
 
 
Introduction
Recently, an increased incidence of suicide among students has triggered immense public concern regarding the mental health of adolescents and young adults. In 2014, there were 52 suicides in the age-group 15 to 24 years. The number of suicides in this age-group increased in subsequent years to 68 in 2015 and 75 in 2016.1 A report from the Centre for Health Protection in Hong Kong showed that, in 2012, the prevalences of mild, moderate, and severe depressive symptoms in adolescents and children were 36.4%, 14.7%, and 4.2%, respectively.2 The Population Health Survey 2003/2004 conducted collaboratively by the Department of Health and the Department of Community Medicine of the University of Hong Kong revealed that the median score for the State-Trait Anxiety Inventory was highest in those aged 25 to 34 years, whereas the median score for the Centre for Epidemiologic Studies Depression Scale was highest in those aged 15 to 34 years.3 A web-based survey targeting first-year students receiving tertiary education in Hong Kong concluded that, in 2006, the prevalence of depression was 20.9%, while that of anxiety was 41.2%.4 Another recent study, the Hong Kong Mental Morbidity Survey,5 revealed that the most common mental problem in Hong Kong was mixed anxiety and depressive disorder; moreover, there was a strong association between anxiety symptoms and depressive symptoms.
 
According to the Diagnostic and Statistical Manual of Mental Disorders, published by the American Psychiatric Association, major depressive disorder is defined as the presence of five or more of the listed symptoms for most of the days during the same 2-week period; at least one of the symptoms must be either depressed mood or loss of interest or pleasure. Notably, these symptoms should reflect a change from previous functioning. Generalised anxiety disorder (GAD) is characterised by excessive worries that cause distress and interfere with psychosocial functioning. These worries frequently happen without precipitants, exhibit longer durations, and are accompanied by three or more of the six listed additional symptoms.
 
Various factors associated with major depressive disorder and GAD have been identified, including alcohol use, illicit drug use, tobacco use, and level of physical activity.6 However, evidence for an association between academic pressure and these two psychiatric disorders remains unknown among university undergraduate students in Hong Kong. We aimed to provide an update regarding the prevalence of depressive and anxiety symptoms experienced by undergraduate students in Hong Kong, and to identify factors associated with these symptoms.
 
Methods
Full-time undergraduate students of the eight universities in Hong Kong that are funded by the University Grants Committee (UGC) were the target participants in this study. A cross-sectional study design was employed and the target number of students to be enrolled from each university was 150; the total target number of students to be recruited was 1200.
 
The inclusion criteria for this study were as follows: full-time undergraduate students in the eight UGC-funded universities who were ≥18 years, were able to understand the consent, provide a valid oral consent, comprehend the questionnaire, and had not previously participated in this research. Students who failed to fulfil all inclusion criteria were excluded from the study.
 
Convenience sampling was employed. Questionnaires were distributed at popular locations within all eight university campuses on school days in September and October 2016. Participants were asked to complete three sets of questionnaires, including the 9-item Patient Health Questionnaire (PHQ-9) for screening of depressive symptoms, the 7-item GAD scale (GAD-7) for screening of anxiety symptoms, and a socio-demographic questionnaire to identify factors associated with depressive and anxiety symptoms.7 8 When completed questionnaires were being returned, respondents were reminded that they would not be able to withdraw from the study after returning the questionnaires, as the questionnaires did not contain any personal identifying information to allow individual retrieval.
 
The PHQ-9 was adopted to screen for depressive symptoms in this study. Both Chinese and English versions were provided. The PHQ-9 has been shown to be a valid and reliable tool for assessing depressive symptoms in the Hong Kong general population.7 8 Another study showed that the PHQ-9 was a useful tool to detect both major depression and subthreshold depression.9 According to the PHQ-9, a score of <5 was defined as none-minimal depressive symptoms, score of 5 to 9 as mild, score of 10 to 14 as moderate, score of 15 to 19 as moderately severe, and score of ≥20 as severe.
 
The GAD-7 is a practical self-report anxiety questionnaire that is generally used in out-patient and primary care settings for referral to a psychiatrist to confirm the diagnosis of GAD. Both Chinese and English versions were available. The adoption of GAD-7 in this study was due to its good reliability, as well as its criteria, construct, and factorial and procedural validity.10 11 According to the GAD-7, a score of <5 was defined as none-minimal anxiety symptoms, score of 5 to 9 as mild, score of 10 to 14 as moderate, and score of ≥15 as severe.
 
Descriptive analysis was performed to summarise the demographics and statuses of depressive and anxiety symptoms of the respondents. A binary logistic regression was conducted to ascertain the effects of various covariates on the odds of exhibiting mild to severe depressive symptoms, on the basis of PHQ-9 results. A PHQ-9 score of <5 was defined as no depressive symptoms, while a score of ≥5 was defined as mild to severe depressive symptoms. Another binary logistic regression was used to ascertain the effects of multiple covariates on the odds that participants would exhibit mild to severe anxiety symptoms, on the basis of GAD-7 results. A GAD-7 score of <5 was defined as no anxiety symptoms, while a score of ≥5 was defined as mild to severe anxiety symptoms. A P value of <0.05 was regarded as a significant difference.
 
Results
In total, 1480 undergraduate students from the eight UGC-funded universities were approached from 6 September 2016 to 3 October 2016. From these, 1200 completed questionnaires were collected, for a response rate of 81.1%. A total of 81 students did not meet at least one of the inclusion criteria and their responses were subsequently excluded from analysis (Fig). The remaining 1119 students fulfilled all inclusion criteria and their responses were analysed by SPSS (Mac version 24; IBM Corp, Armonk [NY], United States).
 

Figure. Flow chart showing the number of validated questionnaires from the eight UGC-funded universities included in the study
 
The mean (standard deviation) age of the respondents was 19.81 (1.48) years (range, 18-29 years). Among the respondents, 426 (38.1%) were male and 693 (61.9%) were female. Most respondents were Chinese (92.7%). The respondents’ demographics are shown in Table 1.
 

Table 1. Demographics of respondents
 
Among the 1119 valid questionnaires analysed, 767 (68.5%) were found to have mild to severe depressive symptoms (Table 2).
 

Table 2. Results of the PHQ-9 (n=1119)
 
For screening of anxiety symptoms, 18 of the 1119 respondents were excluded because they did not complete the GAD-7 questionnaires; therefore, results are based on the 1101 valid responses. A total of 599 (54.4%) respondents were found to have mild to severe anxiety symptoms. A higher prevalence of anxiety was observed in females than males in all three categories of severity (Table 3).
 

Table 3. Results of the GAD-7 (n=1101)
 
The binary logistic regression model for the effects of multiple covariates on the odds of having mild to severe depressive symptoms, on the basis of the PHQ-9 results, was statistically significant with χ2=375.006, P<0.001, with 18 degrees of freedom (Table 4). The model explained 43.1% of the variance in depression severity, as shown by Nagelkerke R2, and correctly classified 79.6% of the cases. Mild to severe anxiety symptoms, as screened by GAD-7, were significantly associated with mild to severe depressive symptoms (P<0.001). In contrast, several lifestyle and psychosocial variables, including regular exercise (P<0.001), self-confidence (P=0.01), satisfaction with academic performance (P=0.019), and optimism towards the future (P<0.001) were inversely related to mild to severe depressive symptoms.
 

Table 4. Binary logistic regression model for the effects of multiple covariates on the odds of having mild to severe depressive symptoms, based on the 9-item Patient Health Questionnaire
 
Another binary logistic regression model for the effects of multiple covariates on the odds of having mild to severe anxiety symptoms, on the basis of the GAD-7 results, was statistically significant with χ2=374.842, P<0.001, with 20 degrees of freedom (Table 5). The model explained 41.3% of the variance in depression severity, as shown by Nagelkerke R2, and correctly classified 76.9% of the cases. Mild to severe anxiety symptoms were associated with level of academic difficulty (P=0.028) and mild to severe depressive symptoms, as screened by PHQ-9 (P<0.001). Certain lifestyle and psychosocial variables, including satisfaction with friendship (P=0.001), sleep quality (P=0.003), and self-confidence (P=0.003) were inversely associated with mild to severe anxiety symptoms.
 

Table 5. Binary logistic regression model for the effects of multiple covariates on the odds of having mild to severe anxiety symptoms, based on the 7-item Generalised Anxiety Disorder scale
 
Discussion
The results revealed that 68.5% of respondents had mild to severe depressive symptoms and 54.4% had mild to severe anxiety symptoms. These rates are higher than and comparable to the results of a similar survey conducted by the University of Hong Kong 10 years ago, respectively.4 This could be attributed to the increasing academic pressure after major reforms of the education system in Hong Kong,12 uncertainties in career prospects due to fluctuations in the socio-political environment, and the more prevalent use of social media.13
 
This study revealed that mild to severe depressive symptoms, as screened by PHQ-9, were associated with mild to severe anxiety symptoms, as screened by GAD-7. This is consistent with previous studies, including a study in patients with depression showing that 85% of those with major depression were also diagnosed with generalised anxiety.14 Sharing common risk factors and symptoms may explain their co-existence.15 16 Another study has shown that anxiety is more frequently an antecedent of depression, but the reverse relationship was not observed.17 This could be explained by the withdrawal and submissive techniques adopted by individuals with anxiety, in response to social exclusion.18 However, a definite causal relationship remains unclear.
 
Regular exercise could decrease the occurrence of depression via both physiological and psychological mechanisms. Exercise exerts an excitatory effect on the monoamine and endorphin neurotransmitter systems; notably, monoamines are depleted in patients with depression.19 Psychologically, exercise is reported to improve self-esteem and self-perception through self-actualisation and gaining pleasure from an expanded social circle.20
 
Psychosocial factors, including higher self-confidence, satisfaction with academic performance, and optimism towards the future are inversely related to depressive symptoms. These could be the presentation or consequences of depression; these factors may have protective effects against developing depression.21 Optimism towards the future, apart from personal factors, is also related to community factors. Risk factors include community disadvantage, safety, and discrimination; an important protective factor is community connectedness. These factors were associated with depressive symptoms.22 This implies that, in addition to promoting personal mental health, community-level risk and protective factors that affect individuals’ optimism towards future are sufficiently important to receive broader attention.
 
For the analysis of anxiety, the level of academic difficulty was associated with mild to severe anxiety symptoms. A higher level of academic difficulty may create greater stress and anxiety for students; subsequent unsatisfactory academic results may complete the vicious cycle. Several tips were suggested by the Anxiety and Depression Association of America (ADAA) regarding test anxiety reduction.23 Female gender was not associated with mild to severe anxiety symptoms, which conflicts with previous studies.15 No clear causality was identified, but some potential aetiologies include higher stress levels from academic and interpersonal issues.
 
Satisfaction with friendship, sleep quality, and self-confidence were three factors inversely associated with mild to severe anxiety symptoms. Having good interpersonal relationships with peers could be a protective factor against anxiety; however, symptoms of anxiety may also hinder friendship, thus explaining the inverse relationship. Insomnia is a symptom of anxiety. According to a survey conducted by ADAA, worrying about falling asleep at night was identified as a cause for an increased level of anxiety.24 Recommendations that could help in falling asleep and achieving better sleep quality include maintaining 7 to 9 hours of uninterrupted sleep, establishing a regular bedtime routine, and avoiding electronic gadgets, coffee, and tea, as well as designing a relaxing environment for sleeping.24 Lack of self-confidence could be a cause of anxiety, but anxiety symptoms could also diminish one’s self-confidence. A bilateral association is possible.
 
There were several limitations in our study. Firstly, as with all cross-sectional studies, it was not possible to establish causality between the identified factors and symptoms of depression and anxiety. Hence, the identified factors are regarded as associated factors, which could be either the causes or the results of depression or anxiety. To further explore the relationships between these factors and symptoms of depression and anxiety, we reviewed the available literature to provide supporting evidence. Secondly, convenience sampling was adopted, but there could be self-selection bias when inviting students to complete the questionnaires, limited by the locations and times at which questionnaire distribution was conducted. The questionnaires were distributed in the open areas of the eight UGC-funded universities in Hong Kong. Withdrawn university students affected by depression or anxiety might not have been reached or might have refused to participate in the study; hence, the results may be underestimates. Thirdly, we could not attain our target number of 150 students from each university, except from the Hong Kong Polytechnic University. Importantly, this study used screening questionnaires to assess the depressive and anxiety symptoms experienced by the students, but no clinical diagnoses were made by health care professionals. However, with limited resources, the use of validated screening questionnaires was considered a cost-effective approach to explore the situation in general and thus was used in this study. Possible directions for further studies include the implementation of stratified random sampling, expansion of the sample size of the study, and performance of a reliability test to reduce information bias. Including detailed backgrounds of students’ disciplines and faculties, as well as ensuring a diverse population to include both local and non-local students, as well as Chinese-speaking and non-Chinese-speaking students, could allow further subgroup analysis; students from different faculties may experience depressive symptoms or anxiety symptoms at different severities due to differences in curricula. In this research, participants who were screened to have depressive and/or anxiety symptoms were not notified because of the lack of identifiable personal information. Provision of the results to participants and recommendations regarding help-seeking information are suggested for future studies. This study result may not fully reflect the severity of depressive and anxiety symptoms among students, as the study method could not reach severely depressed individuals who had socially isolated themselves.
 
Conclusion
This study showed that over 50% of university students in the eight UGC-funded universities expressed some degree of depressive symptoms (68.5%) or anxiety symptoms (54.4%). Notably, 9% of these university students exhibited moderate to severe depressive symptoms and 5.8% of the studied students showed severe anxiety symptoms. Students with regular exercise, higher self-confidence, better satisfaction with academic performance, and more optimism towards the future experienced fewer depressive symptoms. Students with better satisfaction with friendship, better sleep quality, higher self-confidence, and lower levels of academic difficulty experienced fewer anxiety symptoms.
 
Author contributions
Concept or design of study: KWC Lun, CK Chan.
Acquisition of data: All authors.
Analysis or interpretation of data: All authors.
Drafting of the article: All authors.
Critical revision for important intellectual content: KWC Lun, CK Chan.
 
Acknowledgement
We thank Dr LM Ho, assistant IT director of the Division of Epidemiology and Biostatistics of School of Public Health of the University of Hong Kong, for his statistical support and advice in conducting this study. We also thank the School of Public Health of the University of Hong Kong, for its support in conducting this study.
 
Declaration
All authors have disclosed no conflicts of interest. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Funding/support
The LKS Faculty of Medicine, University of Hong Kong reimbursed project expenses under the title of Health Research Project for HKD500.
 
Ethical approval
This study was reviewed and approved by the Institutional Review Board of the University of Hong Kong/Hospital Authority Hong Kong West Cluster.
 
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2. Centre for Health Protection, Department of Health, Hong Kong SAR Government. Depression: beyond feeling blue. Non-Communicable Diseases Watch 2012. Available from: https://www.chp.gov.hk/files/pdf/ncd_watch_sep2012.pdf. Accessed 20 Apr 2016.
3. Centre for Health Protection, Department of Health, Hong Kong SAR Government. Population Health Survey 2003/2004. Collaborative project of Department of Health and Department of Community Medicine, University of Hong Kong, Available from: https://www.chp.gov.hk/files/pdf/report_on_population_health_survey_2003_2004_en.pdf. Accessed 20 Apr 2016.
4. Wong JG, Cheung EP, Chan KK, Ma KK, Tang SW. Web-based survey of depression, anxiety and stress in first-year tertiary education students in Hong Kong. Aust N Z J Psychiatry 2006;40:777-82. Crossref
5. Lam LC, Wong CS, Wang MJ, et al. Prevalence, psychosocial correlates and service utilization of depressive and anxiety disorders in Hong Kong: the Hong Kong Mental Morbidity Survey (HKMMS). Soc Psychiatry Psychiatr Epidemiol 2015;50:1379-88. Crossref
6. Cairns KE, Yap MB, Pilkington PD, Jorm AF. Risk and protective factors for depression that adolescents can modify: a systematic review and meta-analysis of longitudinal studies. J Affect Disord 2014;169:61-75. Crossref
7. Yu X, Tam WW, Wong PT, Lam TH, Stewart SM. The Patient Health Questionnaire-9 for measuring depressive symptoms among the general population in Hong Kong. Compr Psychiatry 2012;53:95-102. Crossref
8. Wang W, Bian Q, Zhao Y, et al. Reliability and validity of the Chinese version of the Patient Health Questionnaire (PHQ-9) in the general population. Gen Hosp Psychiatry 2014;36:539-44. Crossref
9. Martin A, Rief W, Klaiberg A, Braehler E. Validity of the Brief Patient Health Questionnaire Mood Scale (PHQ-9) in the general population. Gen Hosp Psychiatry 2006;28:71-7. Crossref
10. Spitzer RL, Kroenke K, Williams JB, Löwe B. A brief measure for assessing generalized anxiety disorder: the GAD-7. Arch Intern Med 2006;166:1092-7. Crossref
11. Tong X, An D, McGonigal A, Park SP, Zhou D. Validation of the Generalized Anxiety Disorder-7 (GAD-7) among Chinese people with epilepsy. Epilepsy Res 2016;120:31-6. Crossref
12. Yeh YC, Yen CF, Lai CS, Huang CH, Liu KM, Huang IT. Correlations between academic achievement and anxiety and depression in medical students experiencing integrated curriculum reform. Kaohsiung J Med Sci 2007;23:379-86. Crossref
13. O’Keeffe GS, Clarke-Pearson K, Council on Communications and Media. The impact of social media on children, adolescents, and families. Pediatrics 2011;127:800-4. Crossref
14. Hall RC, Platt DE, Hall RC. Suicide risk assessment: a review of risk factors for suicide in 100 patients who made severe suicide attempts. Evaluation of suicide risk in a time of managed care. Psychosomatics 1999;40:18-27. Crossref
15. Blanco C, Rubio J, Wall M, Wang S, Jiu CJ, Kendler KS. Risk factors for anxiety disorders: common and specific effects in a national sample. Depress Anxiety 2014;31:756-64. Crossref
16. van Ameringen M. Comorbid anxiety and depression in adults: Epidemiology, clinical manifestations, and diagnosis. 15 Jun 2017. Available from: https://www.uptodate.com/contents/comorbid-anxiety-and-depression-in-adults-epidemiology-clinical-manifestations-and-diagnosis. Accessed 24 Jul 2017.
17. Muris P. Normal and Abnormal Fear and Anxiety in Children and Adolescents. London: Elsevier; 2007.
18. Richards CS, O’Hara MW, editors. The Oxford Handbook of Depression and Comorbidity. New York: Oxford University Press; 2014.Crossref
19. Buckworth J, Dishman RK. Exercise Psychology. Champaign: Human Kinetics; 2002.
20. Faulkner GE, Taylor AH, editors. Exercise, Health and Mental Health: Emerging Relationships. New York: Routledge; 2005. Crossref
21. Wang KT. Perfectionism, depression, and self-esteem: a comparison of Asian and Caucasian Americans from a collectivistic perspective [dissertation]. Pennsylvania: The Pennsylvania State University; 2007.
22. Stirling K, Toumbourou JW, Rowland B. Community factors influencing child and adolescent depression: A systematic review and meta-analysis. Aust N Z J Psychiatry 2015;49:869-86. Crossref
23. Anxiety and Depression Association of America. Test Anxiety. Available from: https://www.adaa.org/living-with-anxiety/children/test-anxiety. Accessed 23 Mar 2017.
24. Anxiety and Depression Association of America. Stress and Anxiety Interferes with sleep. Available from: https://www.adaa.org/understanding-anxiety/related-illnesses/other-related-conditions/stress/stress-and-anxietyinterfere. Accessed 23 Mar 2017.

Mortality and morbidity of extremely low birth weight infants in Hong Kong, 2010-2017: a single-centre review

Hong Kong Med J 2018 Oct;24(5):460–5  |  Epub 28 Sep 2018
DOI: 10.12809/hkmj177181
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Mortality and morbidity of extremely low birth weight infants in Hong Kong, 2010-2017: a single-centre review
KL Hon, MB, BS, MD1; Sharon Liu, MB, ChB2; Joey CY Chow, MB, ChB2; Kathy YC Tsang, MPhil1; Hugh S Lam, MBBChir, MD1; KW So, MB, BS, MRCP3; Yvonne KY Cheng, MB, ChB, MRCOG4; Alexander KC Leung, MB, BS, FRCPC5; William Wong, MB, BS1
1 Department of Paediatrics, The Chinese University of Hong Kong, Shatin, Hong Kong
2 Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
3 Department of Paediatrics, Prince of Wales Hospital, Shatin, Hong Kong
4 Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Shatin, Hong Kong
5 Department of Pediatrics, University of Calgary, Canada
 
Corresponding author: Prof KL Hon (ehon@hotmail.com)
 
 Full paper in PDF
 
Abstract
Background: Extremely low birth weight (ELBW) infants exhibit high rates of mortality and morbidity. We retrospectively assessed factors associated with mortality and morbidity among ELBW infants.
 
Methods: Perinatal demographic data were reviewed for all ELBW infants born between 2010 and 2017 at a tertiary neonatal unit.
 
Results: For non-survivors (21% of ELBW infants) and survivors, the median gestational ages were 24.1 and 26.2 weeks, respectively, and median birth weights were 650 g and 780 g, respectively (all P<0.001). Regression analyses showed that non-survival was positively associated with lower gestational age (adjusted odds ratio [aOR]=6.71 for every 1-week decrease; 95% confidence interval [CI]=1.73-26.00; P=0.006) and grade 3 or 4 intraventricular haemorrhage (aOR=29.23; 95% CI=1.39-613.84; P=0.030); non-survival was negatively associated with the presence of bronchopulmonary dysplasia (aOR=0.01; 95% CI= <0.001-0.23; P=0.005); length of neonatal intensive care unit stay for survivors was positively associated with the presence of necrotising enterocolitis (B-coefficient=89.60; 95% CI=43.86-135.34; P<0.001); and length of hospital stay for survivors was positively associated with the presence of necrotising enterocolitis (B-coefficient=2.08; 95% CI=0.43-3.73; P=0.015) and a low Apgar score at 1 minute (B-coefficient= –0.63; 95% CI= –1.04 to –0.22; P=0.003).
 
Conclusion: Extremely low birth weight infants exhibited significant mortality and morbidity; there was no survival prior to 23.6 weeks’ gestation or below 550 g birth weight. The presence of grade 3 or 4 intraventricular haemorrhage was independently associated with non-survival. Survivors were significantly more likely to exhibit bronchopulmonary dysplasia; survivors with necrotising enterocolitis were more likely to require longer stays in the neonatal intensive care unit and in hospital.
 
 
New knowledge added by this study
  • Extremely low birth weight infants in Hong Kong showed significant mortality and morbidity: there was no survival prior to 23.6 weeks’ gestation or below 550 g birth weight in this series.
  • The presence of grade 3 or 4 intraventricular haemorrhage was independently associated with non-survival.
  • Survivors were significantly more likely to exhibit bronchopulmonary dysplasia.
  • Survivors with necrotising enterocolitis were significantly more likely to require longer stays in both the neonatal intensive care unit and hospital.
Implications for clinical practice or policy
  • Parents in Hong Kong with extremely low birth weight infants should be counselled regarding expectations for infant survival and associated complications.
  • Hong Kong hospitals can modify their practices to support an increased rate of survival and decreased rate of complications among extremely low birth weight infants.
  • These findings may guide future neonatal health policy and funding in Hong Kong.
 
 
Introduction
Extremely low birth weight (ELBW) infants (birth weight <1000 g) have high rates of mortality and morbidity.1 2 The survival of ELBW infants has improved significantly with the widespread use of exogenous surfactant agents, maternal steroids, mechanical ventilation, and advancements in neonatal technologies.1 3 4 5 6 7 The minimum age of viability is currently regarded as 21 to 22 weeks’ gestation; accordingly, there have been scattered reports of survivors born at 21 to 22 weeks’ estimated gestation.2 8 9 10 11 Periviable birth is defined as delivery occurring from 20 weeks to 25 weeks 6 days of gestation.12 Notably, the rate of survival at 3 years for infants born at 22 weeks’ gestation has been reported as approximately 36% in some centres.13 This study aimed to review mortality and morbidity of ELBW infants at a tertiary neonatal unit in Hong Kong.
 
Methods
Demographic and clinical data were analysed for consecutive neonates admitted to the neonatal unit of a university-affiliated teaching hospital (Prince of Wales Hospital) in Hong Kong between 1 January 2010 and 30 June 2017. During the study period, the Prince of Wales Hospital provided regional neonatal intensive care service for the Eastern New Territories of Hong Kong, with a catchment population of over 1.1 million (approximately 25% were children aged <12 years). A standard data form was used for data abstraction by the investigators. All Clinical Management System records, in-patient records, and computerised laboratory data were examined. Numerical data were expressed as median (interquartile range) and compared by using the Mann-Whitney U test; categorical data were compared by using the Chi squared test, or Fisher’s exact test for data fields that contained >20% cells with an expected count <5. Backward binary logistic regression was conducted on mortality; backward linear regressions were conducted on lengths of neonatal intensive care unit (NICU) stay and hospital stay for survivors. Corresponding Kaplan-Meier survival curves were constructed with survival distribution comparisons by log-rank test using SPSS (Windows version 20.0; IBM Corp, Armonk [NY], US). Two-tailed P values <0.05 were considered statistically significant.
 
Results
A total of 78 ELBW neonates were admitted to the NICU between 1 January 2010 and 30 June 2017; 16 of these neonates died (mortality 21%) [Table 1]. For non-survivors and survivors, the median gestational ages were 24.1 and 26.2 weeks, respectively, and birth weights were 650 and 780 g, respectively (P<0.001). The median (interquartile range) of NICU stay before death was 2.5 (2.0-11.5) days. The median durations of NICU stay and total hospital stay among survivors before discharge were 93.5 days and 4.1 months, respectively. Backward binary logistic regression analysis showed that non-survival was associated with lower gestational age (adjusted odds ratio [aOR]=6.71 for every 1-week decrease; 95% confidence interval [95% CI]=1.73-26.00; P=0.006) and grade 3 or 4 intraventricular haemorrhage [IVH] (aOR=29.23; 95% CI=1.39-613.84; P=0.030); non-survival was negatively associated with the presence of bronchopulmonary dysplasia (BPD) [aOR=0.01; 95% CI=<0.001-0.23; P=0.005), after adjustment for multiple births, caesarean section, birth weight, Apgar score at 1 minute, antenatal steroid administration, infant apnoea, necrotising enterocolitis (NEC), retinopathy of prematurity (ROP), and anaemia of prematurity in the first step of the regression analysis (Table 2). Backward linear regression revealed that the length of NICU stay for survivors was positively associated with the presence of NEC (B-coefficient=89.60; 95% CI=43.86-135.34; P<0.001), after including gestational age, caesarean section, birth weight, Apgar score at 1 minute, and blood stream infection in the first step of the regression analysis (Table 3). The length of hospital stay was positively associated with presence of NEC (B-coefficient=2.08; 95% CI=0.43-3.73; P=0.015), but negatively associated with Apgar score at 1 minute (B-coefficient= –0.63; 95% CI= –1.04 to –0.22; P=0.003), after including gestational age, birth weight, Apgar score at 1 minute, and Apgar score at 5 minute in the first step of the regression analysis (Table 3).
 

Table 1. Demographics and clinical factors of ELBW infants (n=78)
 

Table 2. Logistic regression analysis of mortality (n=78)
 

Table 3. Linear regression analysis of length of NICU or hospital stay for survivors (n=62)
 
Survival curves were constructed for gestational age (Fig 1) and birth weight (Fig 2). Median Kaplan-Meier survival estimates for gestational ages <24, 24, and 26 weeks were 43%, 52%, and 92%, respectively (no death records were available for other groups), during the period of postnatal NICU stay before discharge; importantly, their survival distributions were significantly different (χ2=31.1; P<0.001). Median Kaplan-Meier survival estimates for birth weights <600 g, 600 to 699 g, and 700 to 799 g were 55%, 63%, and 81%, respectively (no death records were available for other groups); their survival distributions were significantly different (χ2=13.9; P=0.008) [Fig 2].
 

Figure 1. Kaplan-Meier survival curve according to gestational age (n=78)
 

Figure 2. Kaplan-Meier survival curve according to birth weight (n=78)
 
Discussion
Extremely low birth weight infants, especially those born at periviable gestations of 22 to 23 weeks, exhibit significantly higher mortality. In this cohort of ELBW infants, we confirmed two independent factors associated with ELBW non-survival: gestation age below 24 weeks and the presence of grade 3 or 4 IVH. Although not specifically analysed in this series, congenital anomalies did not appear to be a pertinent risk factor influencing survival among ELBW infants. Among infants in the non-survival group, the median time until death was 2.5 days after birth; in our series, no survival was observed for ELBW infants whose birth occurred prior to 23.6 weeks or who exhibited birth weight of <550 g. These local data are expected to be useful in counselling pregnant women who are at risk for the delivery of ELBW infants. Non-survival was associated with an increased aOR of 6.7 for every 1-week decrease in gestation.
 
In addition to perinatal mortality, long-term survival was also low. A previous report stated that first-year survival was 15.5% for infants whose birth weight was <500 g.14 Infants with ELBW are more susceptible to all complications of prematurity, both during the immediate neonatal period and after discharge from the nursery. A study by the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network,15 undertaken to relate other known risk factors with the likelihood of survival and impairment, reported that 83% of infants born at 22 to 25 weeks’ gestation received intensive care involving mechanical ventilation. Of the infants whose outcomes were known at 18 to 22 months, 49% died, 61% died or had profound impairment, and 73% died or had impairment.
 
Additional reports have suggested that other factors should be considered, in combination with gestational age, when determining the likelihood of favourable outcomes with intensive care.15 16 17 18 19 According to the data from a 2011 cohort study, infants born at 23 to 25 weeks’ gestation who received antenatal exposure to corticosteroids exhibited a lower rate of mortality and complications, compared with infants who did not have such exposure.16 Recently, chorioamnionitis was linked to preterm birth and neonatal infection. In a longitudinal observational study that included 2390 extremely preterm infants (gestational age <27 weeks), Pappas et al20 reported that antenatal exposure to chorioamnionitis appeared to increase the odds of cognitive impairment, as well as death/neurodevelopmental impairment.
 
Survival occurred in 79% of ELBW infants at our centre. Extremely low birth weight survivors exhibited significant morbidity. Our series showed that BPD, severe IVH, NEC, and ROP were present in 81%, 20%, 26%, and 34% of survivors, respectively. Notably, the survivors experienced long stays in the NICU and hospital prior to discharge. Necrotising enterocolitis is particularly associated with long stays in the NICU and hospital. The sequelae of low birth weight have been well-studied, but less information is available regarding sequelae of ELBW.21 Low birth weight is generally closely associated with fetal and perinatal mortality and morbidity, inhibited growth and cognitive development, and a risk of chronic diseases later in life. At the population level, the proportion of infants with low birth weight is an indicator of a multifaceted public health problem that includes long-term maternal malnutrition, poor health, hard work, and poor health care during pregnancy. On an individual basis, low birth weight is an important predictor of newborn health and survival, and is associated with a higher risk of infant and childhood mortality.21 In this regard, ELBW represents the most severe subset of low birth weight outcomes.
 
Bronchopulmonary dysplasia, grade 3 or 4 IVH, and ROP occurred in a significant proportion of the survivors. Our morbidity data are comparable to those reported in multiple large studies.8 22 23 In recent years, ELBW infants have constituted more than 97% of cases of BPD.24 Importantly, NEC is the most common intestinal emergency in preterm infants.25 26 The routine use of antenatal steroids and surfactant therapy has resulted in increased survival of infants with ELBW, thereby increasing the survival rate in the group at the greatest risk.27
 
The incidence and severity of IVH are inversely related to gestational age. Infants with ELBW are at particular risk for IVH; however, the use of antenatal steroids decreases the incidence of IVH. Prognosis is correlated with the grade of IVH28; up to 40% of infants with grade 3 IVH exhibit significant cognitive impairment, and up to 90% of infants with grade 4 IVH exhibit major neurologic sequelae, requiring lifetime care. Notably, a study of 1064 infants born at ≤28 weeks’ gestation found that, unless it was accompanied or followed by a white matter lesion, low-grade IVH was associated with a modest to nonexistent risk of adverse developmental outcomes during infancy.29
 
The outcomes of ELBW infants are evolving as therapy and supportive care continue to change.1 Clinical focus should be placed on the prevention of premature births, as well as equipping NICU staff and facilities with the necessary skills and resources, respectively, to implement evidence-based interventions that improve the survival of ELBW infants. Efforts to minimise injury, preserve growth, and identify interventions focused on antioxidant and anti-inflammatory pathways are currently being evaluated. Thus, treatment and prevention of long-term deficits must be developed in the context of an evolving target. Ensuring health in cases of extreme prematurity (≤23 weeks’ gestation) is extremely difficult.2 Most centres do not have minimum birth weight criteria for resuscitation; often, a “trial of life” may be discussed with the parents before the birth of the infant so that the infant can be resuscitated and evaluated for viability after birth. Viability is the term frequently used to indicate the potential for a fetus to be liveborn and capable of surviving to a specified endpoint (eg, a designated time, attainment of a certain age or landmark event, admission to the NICU, or discharge from the hospital). Many institutions have generated centre-specific data regarding the probability of survival to aid in discussions with families prior to delivery. Discussions regarding the withdrawal of treatment or support are often necessary when the family and medical team agree that the continuation of medical treatment is not in the infant’s best interests. Naturally, these circumstances involve numerous ethical, moral, and legal issues; they may generate more questions than answers. Therefore, each centre caring for ELBW infants must carefully follow and analyse their particular survival statistics, in order to better inform and guide parents concerning the outcomes and prognoses of these periviable infants.
 
Author contributions
Concept or design: KL Hon, S Liu, JCY Chow.
Acquisition of data: KL Hon, S Liu, JCY Chow.
Analysis and interpretation of data: KL Hon, KYC Tsang.
Drafting of the article: KL Hon, Y Cheng, AKC Leung.
Critical revision for important intellectual content: All authors.
 
Declaration
As an editor of the journal, KL Hon was not involved in the peer review of the article. All authors have disclosed no conflicts of interest. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Funding/support
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
Ethical approval
Ethics approval for this study was obtained from the Clinical Research Ethics Committee of The Chinese University of Hong Kong.
 
References
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9. Berger TM, Bernet V, El Aama S, et al. Perinatal care at the limit of viability between 22 and 26 completed weeks of gestation in Switzerland. 2011 revision of the Swiss recommendations. Swiss Med Wkly 2011;141:w13280. Crossref
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17. Lee HC, Green C, Hintz SR, et al. Prediction of death for extremely premature infants in a population-based cohort. Pediatrics 2010;126:e644-50. Crossref
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Genetic profile and clinical application of chromosomal microarray in children with intellectual disability in Hong Kong

Hong Kong Med J 2018 Oct;24(5):451–9  |  Epub 28 Sep 2018
DOI: 10.12809/hkmj187260
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Genetic profile and clinical application of chromosomal microarray in children with intellectual disability in Hong Kong
Purdy YT Chan, FHKCPaed, FHKAM (Paediatrics)1; HM Luk, MD (HK), FHKAM (Paediatrics)2; Florence MY Lee, FHKCPaed, FHKAM (Paediatrics)1; Ivan FM Lo, FHKCPaed, FHKAM (Paediatrics)2
1 Child Assessment Service, Department of Health, Hong Kong
2 Clinical Genetic Service, Department of Health, Hong Kong
 
Corresponding author: Dr Ivan FM Lo (con_cg@dh.gov.hk)
 
 Full paper in PDF
 
Abstract
Introduction: Chromosomal microarray (CMA) is recommended as a first-tier genetic investigation for intellectual disability (ID), developmental delay, or autism spectrum disorder due to its higher diagnostic yield with respect to conventional karyotyping. The aim of the present study was to investigate the genetic profile and diagnostic yield of CMA in children with moderate, severe and profound ID.
 
Methods: A pilot cross-sectional study was performed by the Child Assessment Service and the Clinical Genetic Service in Hong Kong from July 2016 to June 2017. Children with unexplained ID were recruited for CMA testing by an expedited referral pathway. Children who were existing clients of the Clinical Genetic Service were also recruited.
 
Results: Of 225 children included in this study, 68 (30.2%) had genetic diagnoses. Among the 138 children who underwent CMA testing, 53 (38%) children were referred to the Clinical Genetic Service by the expedited referral pathway. The respective diagnostic yields of CMA in moderate, severe, and profound ID were 8.7%, 17.6%, and 23.5% (P<0.05). Children with dysmorphic features demonstrated a much higher yield from CMA (45.8% vs 4.4%, P<0.05).
 
Conclusion: The overall diagnostic yield (11.6%) of CMA in this cohort is comparable with that of other international cohorts. This further supports the use of CMA as a first-tier genetic investigation for children with ID, developmental delay, or autism spectrum disorder, particularly for those with severe disease.
 
 
New knowledge added by this study
  • Approximately one-third of children with more severe forms of intellectual disability exhibited a genetic condition, as determined by chromosomal microarray.
  • The diagnostic yield of chromosomal microarray testing increases with the severity of intellectual disability, and with the severity of dysmorphic features.
Implications for clinical practice or policy
  • The expedited mechanism, if extended to younger children with developmental delay (with or without autism spectrum disorder), may avoid unnecessary investigations in children, improve the efficiency of service delivery, and reduce societal cost.
 
 
Introduction
Intellectual disability (ID) is estimated to affect 1% to 3% of the population in Western societies.1 It is almost two-fold greater in prevalence in low-and middle-income countries, compared with high-income countries. Importantly, the General Household Survey in 2014 showed the prevalence rate of ID to be approximately 1.0% to 1.4% in Hong Kong.2
 
Intellectual disability is defined as ‘significant limitations both in intellectual functioning and in adaptive behaviour, as expressed in conceptual, social, and practical adaptive skills’.3 These difficulties are evident above the age of 18; ID is indicated by an intelligence quotient (IQ) of approximately two standard deviations (SD) or more below the population mean (IQ ≤70) on the IQ test.
 
Developmental delay (DD) describes the developmental level of a child, typically <5 years old, who is substantially below the average standard of his peers. Global DD is defined as a significant delay in two or more domains: gross motor, fine motor, language, cognitive, social, or activities of daily living. Significant delay refers to scores >2 SD below the mean on norm-referenced age-appropriate developmental tests.4
 
In 2015 and 2016, more than 3000 children per year were diagnosed with DD by the Child Assessment Service (CAS). A study conducted in 2003 to 2004 showed that 80% of children with significant delay and 30% of children with borderline delay were later confirmed to exhibit ID at an older age.5 Overall, 30% of children with ID had a co-morbid diagnosis of autism spectrum disorder (ASD).
 
The aetiology of ID is complex. While milder forms of ID are suspected to typically result from the interplay of genetic and environmental factors,6 biological causes, particularly genetic causes, are often identified in children with significant cognitive delays (IQ <50).4 Rauch et al7 studied 670 subjects, generally <6 years of age, with ID: in 39.5%, ID was related to a genetic cause; in 1.3%, it was due to an acquired or environmental cause; and in 50% to 60%, it did not exhibit a known aetiology.
 
Chromosomal microarray (CMA) or array comparative genomic hybridisation, is recommended by many international professional organisations as a first-tier genetic investigation for children with unexplained DD, ID, or ASD.4 8 9 Compared with conventional karyotyping, CMA is able to detect copy number variants (CNVs) with much finer resolution and is not reliant on staining and visual resolution limits. In 2010, a review of 33 published studies—involving 21 698 patients with DD, congenital anomalies, or autism—found the diagnostic yield of CMA to be 15% to 20% across all studies, compared with 3% for the standard G-banded karyotype.9 In a group of 94 patients with no symptoms other than ID, and no clear dysmorphic features, the diagnostic yield was 6.4%.8 According to the American Academy of Neurology guideline in 2011, CMA testing was abnormal in approximately 7.8% of patients with global DD or ID. The yield was higher (10.6%) in those with syndromic features.8
 
Children with ASD who had co-morbid ID were more likely to yield molecular diagnoses.10 Approximately 10% of patients with ASD exhibit a de-novo CNV, as detected by CMA.11 Among ASD children without syndromic features, only 6% received a molecular diagnosis.
 
In Hong Kong, two studies have investigated the use of CMA in patients with DD, ID, ASD, or multiple congenital anomalies (MCA). Chong et al12 found clinically significant CMA results in 20 of 105 patients (19%). Tao et al13 found a diagnostic yield of 11% for pathogenic or likely pathogenic results in 327 children, ages 1 month to >20 years. Excluding patients with MCA, the diagnostic yield of CMA for DD, ID, or ASD was approximately 4.2%.13
 
Chromosomal microarray has high clinical utility. Firstly, it shortens the diagnostic odyssey and may avoid unnecessary investigations, which reduces both individual and societal costs associated with testing and medical care.8 14 Secondly, it may lead to a clinically actionable recommendation. The prognostic information related to diagnosis from CMA may alert other potential co-morbid conditions that cannot be predicted on the basis of physical examination alone. In a retrospective review of 1792 patients with DD, ID, ASD, or MCA who underwent CMA testing, individuals with a positive diagnosis had a higher rate of clinical actionable recommendations than those with an uncertain result (54% vs 34%, P=0.01).15 In Hong Kong, a detection rate of 8.6% was reported for clinically actionable CNVs,13 which was comparable to the reported rates of 3.6% to 7% in Western studies.15 16 17 Thirdly, it allows estimation of recurrence risk and informed decisions regarding reproductive options for the parents’ future pregnancies.
 
Children’s cognitive development at ≥5 years of age is more stable if the level of ID is known. Children with DD undergo assessment at CAS to facilitate their transition into primary school. Since 2012, the Clinical Genetic Service (CGS) of the Department of Health has provided CMA testing for DD, ID, or ASD. The presence of dysmorphic features, early onset of DD, increased severity of DD, and family history are common features that prompt a genetic referral. Collaboration between CAS and CGS can potentially narrow the service gap for children with DD, ID, or ASD by enabling early access to diagnostic genomic testing, thus facilitating shorter waiting time for genetic and genomic investigation(s) and a more client-friendly turnover time for results.
 
The aim of this study was to investigate the genetic profile and diagnostic yield of CMA in children with moderate, severe, and profound ID. The data obtained from this study are expected to be useful in future service planning for children with DD or ID. The diagnostic yield of CMA for children with more severe forms of ID is suspected to be higher than the generally quoted figures of CMA (10%) for investigation of ID. This study targeted children with more significant ID, which is more likely to be related to an underlying genetic aetiology.
 
Methods
This cross-sectional territory-wide study recruited children who attended CAS for developmental assessments, before Primary 1 entry, over a 12-month period from July 2016 to June 2017. All children were at least 5 years of age. Inclusion criteria were children with moderate, severe, or profound ID, with or without ASD. According to the International Statistical Classification of Diseases and Related Health Problems, tenth revision,18 moderate ID was defined as IQ 35 to 49; severe ID was defined as IQ 20 to 34; and profound IQ was defined as IQ <20. Exclusion criteria included known causes of ID: (i) antenatal causes such as congenital brain malformation or intrauterine infections; (ii) perinatal causes such as prematurity (<34 weeks), birth asphyxia, or hypoxic ischaemic encephalopathy; (iii) postnatal causes such as intracranial bleeding, intracranial infection, or brain trauma; and (iv) other biological causes such as inborn errors of metabolism, brain tumour, neuromuscular disorders, neurodegenerative disorders, or cerebral palsy.
 
Unexplained ID in this study was defined as children with no identifiable causes for ID who did not meet any of the exclusion criteria. These children were non-syndromic and non-dysmorphic. In addition, they had neither MCA nor family history of ID or ASD among first- and second-degree relatives. The presence of MCA was defined as the involvement of two or more organ systems.
 
Children were assessed by paediatricians with the Griffiths Mental Developmental Scales,19 or by clinical psychologists with the Wechsler Preschool and Primary Scale of Intelligence–Revised.20 The Diagnostic and Statistical Manual of Mental Disorders, 4th edition,21 ASD diagnostic criteria were used for assessment of ASD.
 
Genetic profile
For children with genetic diagnoses or who were known clients of CGS, their medical files were retrieved from CAS and CGS for review. Children with syndromic or dysmorphic features, MCA, or significant family history, who had not been previously referred to CGS, were referred for a formal genetic consultation before genetic or genomic investigations were recommended by a clinical geneticist.
 
An expedited pathway was offered for children with unexplained ID. Pre-genetic counselling was provided by a paediatrician at CAS, followed by direct blood examination for CMA and Fragile X syndrome (FGX) testing at CGS. Consultation with a geneticist was arranged if either CMA or Fragile X testing yielded abnormal outcomes. Otherwise, clients did not consult a geneticist for further counselling.
 
Chromosomal microarray testing and interpretation
For each patient, 3 mL of blood in ethylenediaminetetraacetic acid was sent to the laboratory at CGS. All samples were tested by PerkinElmer CGXTM v2 60K arrays designed by Agilent SurePrint technology, in accordance with the manufacturer’s instructions. The coverage of the array demonstrated an average resolution of 140 kb across the genome, and ≤40 kb in regions of clinical relevance. It evaluated >245 known genetic syndromes and >980 gene regions of functional significance in human development. Data were analysed by Genoglyphix software (Signature Genomics, Spokane [WA], United States). Genomic coordinates were based on genome assembly hg19.
 
Detected CNVs were systematically evaluated for clinical significance by comparison with information in the proprietary Genoglyphix Chromosome Aberration Database (Signature Genomics), internal laboratory database at CGS and the Department of Health, and public databases (Database of Genomic Variants, International Standards for Cytogenomic Arrays Consortium, and Database of Chromosomal Imbalance and Phenotype in Humans using Ensembl Resources). Categorisation of CNVs was based on available phenotypes and comparison of phenotypes with genes in the region of copy gain or loss. This was performed by searching the following databases: Online Mendelian Inheritance in Man, PubMed, RefSeq, and the University of California Santa Cruz genome browser.22 Confirmatory fluorescence in situ hybridisation (FISH), multiplex ligation-dependent probe amplification (MLPA), or conventional karyotyping was performed as indicated. Parental testing was offered to aid further interpretation and classification. Copy number variants were classified as pathogenic, likely pathogenic, uncertain clinical significance, or benign, in accordance with the 2011 American College of Medical Genetics practice guidelines.23 Only pathogenic and likely pathogenic CNVs were regarded as clinically significant.
 
Sample size calculation
The number of subjects to be recruited was estimated based on the average number of children with moderate, severe, and profound ID in the CAS database. In 2013 to 2015, the average number of children with moderate ID or worse was approximately 270 children per year. With the assumption that 60% of cases were unexplained,7 potential cases eligible for CMA were estimated as 160 children per year. Literature showed that the diagnostic yield of CMA was 10% in identifying abnormal cases in similar settings.13 A 95% confidence interval was desired, with a reliability (d) of 0.05, in obtaining a diagnostic yield (ˆp) of 10% in this study. The sample size needed was determined following a previously published method1:
 
 
Hence, a target sample size of 138 was needed.24
 
Statistical analysis
The genetic profile of children in the study was described. The diagnostic yield from CMA was calculated according to the severity of ID. The Freeman-Halton test was used to test associations between the severity of (a) ID and CMA and (b) dysmorphism and CMA findings. The null hypothesis was that there was no association between the severity of ID or dysmorphism and CMA findings. P<0.05 indicated an association between the severity of ID or dysmorphism and CMA findings. The Freeman-Halton test was conducted by using SAS/STAT 9.22.
 
Results
From July 2016 to June 2017, there were a total of 339 children diagnosed with more severe forms of ID: 241 (71%) children had moderate ID, 49 (14.5%) had severe ID, and 49 (14.5%) had profound ID. Eighty-three children were excluded for the following reasons: (1) they met predefined exclusion criteria; (2) their family could not participate due to geographical reasons (eg, family lived in China); (3) a language barrier affected their understanding of study details (eg, the children or their families spoke primarily Nepalese or Sri Lankan); or (4) their parents could not be contacted for consent. A total of 31 children opted not to participate in the study. In all, 225 (66.4%) of 339 children participated in the study.
 
Among the 225 children, 116 (51.6%) had a co-morbid diagnosis of ASD. Male (n=151) to female (n=74) ratio was 2:1. The age ranged from 5 to 10 years old with a mean age of 6.6 years old. In all, 71.5% of children had moderate ID, 14.7% had severe ID, and 13.8% had profound ID. Two hundred twenty-one (98%) children had Chinese parents. There were two pairs of consanguineous parents: one Indian couple and one Pakistani couple.
 
Genetic profile of children with intellectual disability
As shown in Table 1, 68 (30.2%) children were diagnosed with a genetic condition. The percentage of a positive genetic diagnosis increased with the severity of ID. Chromosomal abnormalities comprised 76% (n=52) of the total genetic diagnoses. The most common syndromic diagnosis was Down syndrome (n=22). There were two cases of FGX. Three children had chromosome 22 microdeletion syndromes—one exhibited the more common chromosome 22q11.2 microdeletion syndrome (DiGeorge syndrome), whereas the other two exhibited chromosome 22q13.3 deletion syndrome.
 

Table 1. Genetic profile of children with ID
 
Diagnostic yield of chromosomal microarray in children with intellectual disability
Of the 225 participating children, 138 underwent CMA testing; 53 (38%) children were referred to the Clinical Genetic Service by the expedited referral pathway. Table 2 shows that 16 (11.6%) children demonstrated clinically significant CNVs that explained their ID phenotype and 10 (7.2%) had variants of uncertain significance (VUS). The diagnostic yield of CMA increased with severity of ID: it was 8.7% in moderate ID, 17.6% in severe ID, and 23.5% in profound ID (P<0.05; Table 3). Among the 16 children with clinically significant CNVs, 11 demonstrated copy number loss (deletion), four demonstrated copy number gain (duplication), and one demonstrated an unbalanced translocation between chromosome 7q and 20p (Table 4). One case of Angelman syndrome was detected by CMA and later confirmed with MLPA. One case of Cri du chat syndrome was detected by CMA and later confirmed with FISH. In total, 69% of pathogenic or likely pathogenic CNVs were de novo. Ten children (7.2%) were incidentally identified as carriers of disease: six were alpha thalassemia heterozygous carriers, one was a heterozygous carrier of Joubert syndrome type 4, one was a heterozygous carrier of autosomal recessive disease Joubert syndrome and nephronophthisis, one was a heterozygous carrier of autosomal recessive deafness affecting the OTOA gene, and one was a carrier of Klinefelter syndrome.
 

Table 2. Chromosomal microarray diagnostic yields in unexplained ID
 

Table 3. Chromosomal microarray diagnostic yields based on severity of ID
 

Table 4. Cases with positive chromosomal microarray results
 
Discussion
The overall diagnostic yield of CMA among children with ID (11.6%) was consistent with studies performed in other regions of the world. The diagnostic yield of CMA increased with severity of ID and was much higher in children with dysmorphism (45.8% vs 4.4%, P<0.05).
 
Variants of uncertain significance are not uncommon. In all, 7.2% of children in this cohort had VUS (Table 5). Regular follow-up and reassessment by a clinical geneticist is necessary for these children, because VUS may eventually be re-classified as pathogenic or benign as clinical and genomic data accumulate in the literature.
 

Table 5. Cases with variants of uncertain significance
 
The paradigm shift in the medical genetic and genomic field from the phenotype-first approach to the genotype-first approach is revolutionary. Traditionally, a phenotype-first approach was used to guide the investigation of possible genetic diagnoses, eg, karyotyping for Down syndrome, or specific assays, such as FISH, for DiGeorge syndrome. In the past decade, CMA has allowed more comprehensive unbiased discovery of microdeletion and microduplication syndromes throughout the human genome. Since the 1980s, it has been well-known that certain chromosomal microdeletion and microduplication syndromes are associated with recognisable forms of ID and DD. Classical examples include 15q11-q13 deletion, associated with Prader-Willi and Angelman syndromes, and 22q11.2 deletion, associated with DiGeorge syndrome (velocardiofacial syndrome). Thus far, approximately 50 to 60 recurrent microdeletion or duplication syndromes have been identified in children with DD or ID.
 
Although CMA is robust, it cannot replace a formal genetic consultation for children with clinically suspected genetic conditions. As an example, in Prader-Willi syndrome, 70% to 75% of cases can be detected by CMA, as they are due to a paternal 15q microdeletion subtype; 20% to 25% of cases require a more specific methodology for genetic confirmation. Therefore, clinical correlation and expert assessment remain necessary.
 
Males are more susceptible to ID than females; more than 100 X-linked genes are associated with ID.25 X-linked ID constitutes 5% to 10% of ID in males. One of the best-known causative genes for ID is FMR1; mutations of FMR1 result in FGX. The estimated incidence of FGX is approximately 1 in 4000 males and 1 in 5000 to 1 in 8000 females (approximately 0.5% of cases of ID) in Western countries. Peprah26 reported that the incidence of FGX in countries/regions with significant Asian populations, such as Canada, Estonia, Japan, and Taiwan, was significantly lower than in Western countries. In a study of 553 male children between the ages of 6 months and 18 years, Chen et al27 estimated the prevalence of FGX in mainland China to be approximately 0.93% among children with moderate to severe ID. Among the 225 children in our cohort, only two were diagnosed with FGX. Both exhibited ASD and severe ID. The typical physical characteristics of FGX, such as narrow face, protruding ears, and macro-orchidism, are often less obvious in early childhood; notably, they may become more prominent as the child approaches adolescence. This lack of early physical characteristics increases the diagnostic challenge for clinicians. Fragile X syndrome testing, regarded as first-tier genetic testing for DD and ASD in many international guidelines, has been a standard genetic investigation for ID or ASD in Hong Kong for many years.
 
Incomplete penetrance of a genomic condition within the same family is not uncommon. Notably, there were two such cases of 16p13.11 microduplication syndrome in this cohort. Patient 12 (Table 4) exhibited subtle dysmorphism comprising downslanting palpebral fissures, prominent ears, and mild right ptosis. Left undescended testes and umbilical hernia were operated in infancy. He exhibited global DD and was later diagnosed with moderate ID. His mother and two sisters had an identical chromosomal defect, but exhibited normal intelligence. Patient 13 demonstrated a more severe phenotype with hirsutism, bushy eyebrows, frontal bossing, hearing loss, visual problems, and profound ID. His mother and elder brother, both carrying the microduplication, exhibited normal intelligence. There likely exist unknown environmental or genetic modifiers to modulate susceptibility to ID caused by this microduplication. Thus, relying on family history to determine whether ID is hereditary can be misleading.
 
An important aspect with respect to obtaining a genetic diagnosis is patient prognosis. The 16p13.11 duplication syndrome is associated with an aortic root defect. In this study, the two affected children and their affected family members were referred for monitoring by echocardiogram. Similarly, Patient 2 exhibited 3q13.31 microdeletion syndrome, which is associated with diabetes mellitus and deafness; this patient was referred for audiological assessment and counselled on lifestyle management to minimise the risk of diabetes. In this study, three of 16 CMA-positive cases (18.8%) were clinically actionable.
 
Pre-test genetic counselling is as important as post-test counselling. Coincidental findings of genetic changes that either predict adult-onset conditions or reveal carrier status for recessive or X-linked conditions are common. In the present cohort, 10 children were identified as carriers of genetic conditions, including one child diagnosed with Klinefelter syndrome. He presented with moderate ID and ASD. Chromosomal microarray identified a copy number gain of the entire X chromosome. Klinefelter syndrome can be associated with learning disabilities, as well as delayed speech and language development. While a small, but significant, downward shift in mean overall IQ has been reported, general cognitive abilities of patients with Klinefelter syndrome are not typically in the ID range.28 An extra X chromosome may have contributed partially, but could not entirely explain the severity of ID. The major implications are that individuals with Klinefelter syndrome have a higher risk of endocrine dysfunction, fertility problems, male breast cancer, and autoimmune disease.
 
This study provided important information with respect to service planning for children with ID in Hong Kong. It allowed testing of an expedited referral mechanism between CAS and CGS, in which cases with unexplained ID benefitted through a significant reduction of waiting time for both pre-testing genetic counselling and investigation turnover time. This study included 38% of the 138 children who were not referred to CGS. The ideal future approach may be to extend the expedited mechanism for children with early-onset significant DD. It can avoid unnecessary investigations, thus lowering stress for both child and parent; importantly, it may reduce societal costs.
 
There were several limitations in this study. Firstly, a complete genetic profile of ID was not generated, as this cohort excluded mild ID. Secondly, clients from minority cultural groups in Hong Kong were underrepresented, because the language barrier affected recruitment. More effort must be expended to ensure equal opportunities for children from diverse cultural backgrounds. Thirdly, the duration of the study was of insufficient length for commentary on trends regarding the genetic profile of ID in Hong Kong.
 
Conclusion
The overall diagnostic yield (11.6%) of CMA is compatible with other international cohorts. Chromosomal microarray yield increases with the severity of ID. These data further support the use of CMA as a first-tier investigation for children with significant unexplained ID in Hong Kong.
 
Author contributions
All authors have made substantial contributions to the concept or design of the study, acquisition of data, analysis or interpretation of data, drafting of the article, and critical revision for important intellectual content.
 
Acknowledgement
The authors would like to thank Mr Morris Wu of Child Assessment Service, Department of Health for his advice on the statistical analysis of the data.
 
Declaration
The authors have no conflicts of interest to disclose. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Funding/support
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
Ethical approval
Approval was obtained from the Ethics Committee of the Department of Health, Hong Kong Special Administrative Region. Informed consent was obtained from parents or legal guardians. Parents and legal guardians were counselled about the indication for CMA, benefits and limitations of test, methodology, reporting time, and possible outcomes upon recruitment.
 
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4. Moeschler JB, Shevell M, Committee on Genetics. Comprehensive evaluation of the child with intellectual disability or global developmental delays. Pediatrics 2014;134:e903-18. Crossref
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Effect of paternal age on semen parameters and live birth rate of in-vitro fertilisation treatment: a retrospective analysis

Hong Kong Med J 2018 Oct;24(5):444–50  |  Epub 28 Sep 2018
DOI: 10.12809/hkmj177111
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Effect of paternal age on semen parameters and live birth rate of in-vitro fertilisation treatment: a retrospective analysis
SF Lai, MB, BS, FHKAM (Obstetrics and Gynaecology)1,2; Raymond HW Li, MB, BS, FHKAM (Obstetrics and Gynaecology)1,2; William SB Yeung, PhD1,2; Ernest HY Ng, MD, FHKAM (Obstetrics and Gynaecology)1,2
1 Department of Obstetrics and Gynaecology, The University of Hong Kong, Pokfulam, Hong Kong
2 Department of Obstetrics and Gynaecology, Kwong Wah Hospital, Yau Ma Tei, Hong Kong
 
Corresponding author: Dr SF Lai (lsf087@ha.org.hk)
 
 Full paper in PDF
 
Abstract
Objective: To determine the effect of paternal age on semen parameters and the live birth rate from in-vitro fertilisation (IVF) treatment.
 
Methods: We performed a retrospective cohort study of couples undergoing a first IVF cycle between 2004 and 2014 in a tertiary assisted reproduction centre in Hong Kong.
 
Results: We analysed 3549 cases. Paternal age ≥40 years was negatively correlated with semen volume, progressive motility, total motility and total normal motile count (P<0.005) and positively correlated with sperm concentration (P<0.001). There was no correlation with sperm count, normal morphology, or total motile count. Subgroup analyses in Chinese men only and in men with normal versus abnormal semen parameters showed the same correlations. Paternal age was positively associated with maternal age (P<0.001) and miscarriage (P=0.006), and negatively associated with ongoing pregnancy and live birth (P<0.001). Logistic regression showed that maternal age, total number of oocytes retrieved, and number of embryos transferred were significant factors which independently predicted the likelihood of live birth from IVF (all P<0.001).
 
Conclusion: Paternal age was negatively correlated with some semen parameters, which showed a significant decline after age 40 years. However, paternal age is not predictive of the live birth from IVF treatment.
 
 
New knowledge added by this study
  • Paternal age negatively correlates with some semen parameters.
  • Paternal age is not an independent predictor of the likelihood of a live birth from in-vitro fertilisation treatment, after controlling for the maternal age, the number of oocytes retrieved, and the number of embryos transferred.
Implications for clinical practice or policy
  • Infertile couples can be counselled that although there is a decline in some semen parameters with paternal age ≥40, the live birth rate of in-vitro fertilisation treatment depends primarily on maternal age, number of oocytes retrieved and number of embryos transferred, but not on paternal age.
 
 
Introduction
In recent years, marriages and pregnancies are occurring later and later in life, which was confirmed in a recent large-scale analysis conducted in the US.1 Local statistics in Hong Kong support this trend, as the median age at first marriage for both sexes has risen over the past 20 years.2 3 Extensive data are available on the adverse effects of increasing maternal age on in-vitro fertilisation (IVF) outcomes4 5 6 but little information was on the adverse effects of increasing paternal age.
 
Two systematic reviews have looked at the effect of paternal age on semen parameters and assisted reproduction outcomes.7 8 Dain et al7 demonstrated that paternal age did not affect pregnancy, miscarriage, and live birth rates. The authors also revealed that semen volume decreased with paternal age, but sperm motility, concentration and morphology did not. Later, in another systematic review8 of 12 studies on oocyte donor cycles, the same group showed that advancing paternal age is not associated with adverse outcomes, including pregnancy and live birth rates. They also showed that, except for volume and possibly motility, sperm characteristics such as concentration and morphology did not alter with age. However, most papers studied did not report the live birth rate, which is the most important clinical outcome for the patients involved.
 
The existing information regarding the adverse effects of increasing paternal age on semen parameters and IVF outcomes is mostly from Western populations.7 8 9 Therefore, we conducted this study to determine the effect of paternal age on semen parameters and on the live birth rate of IVF treatment in the Hong Kong population, which is mainly of Chinese ethnicity.
 
Methods
Subject inclusion and exclusion
We retrieved all first IVF cycles carried out between 2004 and 2014 at the Centre of Assisted Reproduction and Embryology, The University of Hong Kong–Queen Mary Hospital from the Assisted Reproduction Clinical Database of the Centre. Only the first IVF cycles using ejaculated semen were included for analysis, to avoid any potential bias. Cases requiring preimplantation genetic diagnosis or using donor sperm or surgically retrieved sperm were excluded from the study.
 
Ovarian stimulation
Details of the treatment protocol has been previously described.10 In brief, women received ovarian stimulation following either the long gonadotropin-releasing hormone (GnRH) agonist or antagonist protocol. A baseline ultrasound was performed on day 2 to 3 of the cycle to exclude pre-existing ovarian cysts. Serum oestradiol (E2) concentration was measured to confirm the basal level. In the long GnRH agonist protocol, intranasal buserelin acetate (Suprecur; Sanofi, France) was started on day 21 of the preceding cycle at 150 μg 4 times a day and continued until the day of ovulation trigger. In the GnRH antagonist protocol, subcutaneous injection of ganirelix 0.25 mg (Orgalutran; Organon, The Netherlands) or cetrorelix 0.25 mg (Cetrotide; Merck Serono, Germany) was started on day 6 after gonadotropin injection until the day of ovulation trigger. Human menopausal gonadotropin (hMG, Menogon; Ferring, Switzerland) or recombinant follicle-stimulating hormone (Gonal-f [Merck Serono, Germany] or Puregon [Organon, The Netherlands]) injection was started at a dosage as determined by the antral follicle count. Ovarian response was monitored by transvaginal ultrasound. Human chorionic gonadotropin (hCG; Profasi [10 000 units; MSD, US] or Ovidrel [250 μg; Merck Serono, Switzerland]) was given to trigger the final oocyte maturation when there were at least three follicles ≥16 mm in diameter, of which one follicle was ≥18 mm. Triptorelin 0.2 mg (Decapeptyl; Ferring, Switzerland) was used to replace hCG if serum E2 concentration was >25 000 pmol/L, if more than 15 follicles were ≥14 mm in diameter on the day of hCG administration, or when the patient had evidence of ovarian hyperstimulation syndrome. Transvaginal ultrasound-guided oocyte retrieval was performed 34 to 36 hours after the ovulatory dose of hCG or triptorelin injection. Instruction on abstinence of sex for 2 to 7 days was given prior to submission of any semen sample. Fresh ejaculated semen samples were evaluated according to World Health Organization guidelines11 12 and the same protocol (including the strict criteria for assessing sperm morphology) was adopted throughout the period covered in this study.
 
Intracytoplasmic sperm injection (ICSI) was performed when the normal morphology of a recent semen sample was <3% or the total motile sperm count after sperm preparation was <0.2 million. The same criteria for ICSI versus conventional insemination was adopted throughout the study period. Fertilisation was assessed 16 to 20 hours after insemination. Embryo transfer was performed under ultrasound guidance 2 days after retrieval. Up to three embryos were transferred before 2006 and a maximum of two embryos were transferred after 2006. Luteal phase was supported with vaginal progesterone pessaries (Cyclogest 400 mg twice a day [Cox Pharmaceuticals, Barnstaple, United Kingdom] or Endometrin 100 mg twice a day [Ferring, Switzerland]) or intramuscular injection of hCG 1500 units every 6 days for two doses. Urine pregnancy test was performed 16 days after embryo transfer. Where the pregnancy test was positive, ultrasound scans were performed at 6 and 8 weeks of gestation to confirm fetal viability and number.
 
Total motile count (TMC) was defined as total sperm count with progressive motility (total count × % with progressive motility). Total normal motile count (TNMC) was defined as sperm count with progressive motility and normal morphology (total count × % with progressive motility × % with normal morphology).
 
Pregnancy was defined by a positive urine or serum hCG test. Miscarriage was defined as a pregnancy which became non-viable before 24 weeks of gestation; this included biochemical pregnancies and miscarriages before 24 weeks. An ongoing pregnancy was defined as presence of intrauterine sac(s) with positive fetal heart pulsation at 8 weeks of gestation. A live birth was defined as the complete expulsion or extraction from a woman of a conceptus after 24 completed weeks of gestational age which, after such separation, showed evidence of life.
 
Statistical analyses
The key outcomes of this study were live birth and semen parameters including volume, concentration, count, progressive motility, total motility, normal morphology, TMC, and TNMC.
 
Statistical analysis was performed using SPSS Windows version 24.0 (IBM Corp, Armonk [NY], US) and MedCalc (Version 12, Belgium). Paternal age of our cohort was not normally distributed as shown by Kolmogorov-Smirnov test (P<0.001). Therefore, non-parametric tests were used for analysis. The Mann-Whitney U or Kruskal-Wallis H tests were used to compare continuous variables among groups. Spearman’s correlation was used to determine correlations between continuous variables. Chi squared test was used for analysis of categorical variables. Logistic regression analysis was used to examine factors predicting live birth, first by univariate analysis of individual variables, and those factors showing significance were subsequently entered into multivariate analysis. A two-tailed value of P<0.05 was considered statistically significant.
 
Results
A total of 3973 first IVF cycles were performed during the study period (Fig). Of these, 424 cases were not selected (230 with a preimplantation genetic diagnosis, 12 using donor sperm, and 182 using surgically retrieved sperm). In ICSI cases, if the sperm concentration was <3 million/mL, morphology would not be evaluated (n=207). Sperm concentration, count and/or normal morphology could not be evaluated in the fresh semen samples of 84 men with severe male factors. Hence, TNMC was only available in 3258 cases.
 

Figure. Flowchart of the cycles for data analysis
 
Cohort demographics are shown in Table 1. The causes of infertility were as follows: tuboperitoneal factor (n=620; 17.5%), endometriosis (n=294; 8.3%), male factor (n=1483; 41.8%), unexplained (n=603; 17.0%), and mixed factors (n=549; 15.5%). Among those analysed, conventional insemination was performed in 2528 (71.2%) cycles and ICSI was required in 1021 (28.8%) cycles. There were 381 (10.7%) cases which did not have fresh embryo transfer for various reasons, leaving 3168 cases with fresh embryo transfer. There were 1613 pregnancies, giving a pregnancy rate of 50.9% per transfer. Of these pregnancies, 241 (14.9%) miscarried before 8 weeks of gestation. An additional 43 (2.7%) cases miscarried after 8 weeks of gestation. Four (0.2%) women terminated their pregnancy due to congenital abnormalities (n=3) or for social reasons (n=1). Five (0.3%) pregnancies ended in intrauterine death.
 

Table 1. Demographics of the cohort
 
Paternal age was negatively correlated with the semen volume, progressive motility, total motility, and TNMC (P<0.005), as shown in Table 2. Paternal age was positively correlated with sperm concentration (P<0.001). Paternal age was not correlated with sperm count, normal morphology, or TMC.
 

Table 2. Correlation of paternal age with semen parameters and IVF parameters
 
We divided paternal age into two groups (<40 years and ≥40 years) and analysed the difference in semen parameters using the Mann-Whitney U test. Results showed a significant decline in semen volume, progressive motility, total motility and TNMC (P<0.005), but a significant increase in sperm concentration for age ≥40 years (P<0.001). There was no significant difference in sperm count, normal morphology, TMC or fertilisation rate between the age-groups (P>0.05). These findings support the correlations shown in Table 2.
 
The analyses were repeated in the subset including Chinese men only (n=3394, 95.6%), and showed similar correlations between age and semen parameters and IVF outcomes.
 
When men were grouped into those with normal and abnormal semen parameters, the negative correlation of paternal age with semen volume, progressive motility, total motility and TNMC and the positive correlation with sperm concentration remained the same as that for the whole cohort.
 
Paternal age was not significantly associated with the fertilisation rate in the conventional IVF group (P=0.786), in the ICSI group (P=0.801), or overall (P=0.810) as shown in Table 2. Paternal age was positively correlated with maternal age (Spearman’s correlation coefficient: 0.487; P<0.001). Paternal age was significantly lower in those who attained pregnancy, ongoing pregnancy and live birth compared with those who did not (P<0.001; Mann-Whitney U test). In contrast, paternal age was significantly higher in cases that ended in miscarriage than in those that achieved live birth (P=0.006; Mann-Whitney U test).
 
The clinical and demographic characteristics of patients with or without a live birth in the first IVF cycles are compared in Table 3. Women who had a live birth were significantly younger (median 35.0 vs 36.0 years), had a younger partner (median 37.0 vs 38.0 years), higher antral follicle count (median 11 vs 8), more oocytes retrieved (median 9 vs 7), and had double embryo transfer (86.5% vs 74.6%). There was no statistically significant difference in the maternal BMI nor in TNMC between these two groups. The analysis showed similar findings between pregnant versus non-pregnant groups and between those with ongoing pregnancy and those without.
 

Table 3. Comparison of demographic and clinical characteristics of patients with or without a live birth in the first IVF cycle
 
Logistic regression on individual variables by univariate analysis was used to analyse the prediction on the live birth in the first IVF cycle. Only paternal age, maternal age, total number of oocytes retrieved, and number of embryos transferred were found to be significant predictors. On combining these variables in a multivariate analysis, maternal age, total number of oocytes retrieved and number of embryos transferred, but not paternal age, were the significant factors which independently predicted the likelihood of live birth in the first IVF cycles after controlling for the others (P<0.001), as shown in Table 4.
 

Table 4. Logistic regression analysis of factors for prediction of a live birth in the first IVF cycle
 
Discussion
This is the first large-scale study on the effect of paternal age on semen parameters and IVF outcomes in our region, with the majority of patients being Chinese. Nearly 4000 first IVF cycles were analysed. Most previous studies have reported on oocyte donation models.7 8 Our cohort is the largest sample size in the literature based on autologous oocytes and fresh semen samples, with live birth as one of the key outcomes. Logistic regression analysis was employed to differentiate the factors affecting live birth in the first IVF cycles.
 
Our results show that paternal age was negatively correlated with semen volume, progressive motility, total motility, TNMC but not sperm count, normal morphology nor TMC. The positive correlation between paternal age and sperm concentration might be explained by the decrease in semen volume with age, resulting in an apparent raised sperm concentration. An increase in sperm concentration was also found in a recent study conducted on a similar scale.13 Other studies have mostly reported either no significant change14 15 or a decrease in sperm concentration.16 Although increasing paternal age was not associated with any significant change in normal morphology, the associated significant reduction in progressive motility contributed to an overall negative impact on TNMC. These composite parameters represent the population of sperm relevant to natural fertility. The decline in overall sperm quality with paternal age is likely due to the decline in testicular function.17 The number of Leydig cells,18 Sertoli cells19 and germ cells decreases with paternal age.20 Despite the overall decrease in various semen parameters with age, we found that the fertilisation rate was not significantly reduced with increasing age; this is compatible with most previous studies.7 8
 
Various age cut-offs have been suggested in the literature for defining advanced paternal age but the most frequently used cut-off is age 40 years at the time of conception.21 Both the American Society for Reproductive Medicine and the British Andrology Society recommend that the sperm donor should be age <40 years.22 23 Our results show that there is an inverse relationship in semen parameters with paternal age using the cut-off of age 40 years. Multiple studies have shown that advanced paternal age is associated with a significant increase in DNA fragmentation24 which in turn is associated with higher rate of IVF failure.25 As men age, the sperm chromatin integrity weakens and sperm DNA fragmentation increases.26 Fecundability has been shown to decrease with increased abnormal sperm chromatin percentage.27 The molecular ageing process has been shown to induce changes in reproductive hormone profiles, decreasing in sperm quality parameters, and contributing to male infertility.28
 
On univariate analysis, paternal age was associated inversely with live birth. However, paternal age was also positively correlated with maternal age, meaning that younger men usually have younger partners and vice versa. Logistic regression analysis indicated that maternal age but not paternal age was an independent predictor of the likelihood of live birth, in contrast to some previous studies.29 30 Paternal age is likely a surrogate marker of maternal age and does not have a direct effect on IVF outcomes.
 
The analyses were repeated in the subset including Chinese men only, revealing similar findings on semen parameters and IVF outcomes. However, we are cautious of the interpretation of this finding as the majority of our cohort was Chinese.
 
Although different ovarian stimulation protocols and different medications were used throughout the study period, meta-analyses have shown that there are no differences in the live birth rates between the long GnRH agonist protocol and the GnRH antagonist protocol, between the use of hMG and recombinant follicle-stimulating hormone, nor among the different types of progestogens used for luteal phase support in terms of pregnancy outcomes.31 32 33 34
 
Our study has some limitations. We followed the delivery details of most patients; only 32 patients were lost to follow-up. However, we do not have the information on any congenital abnormalities of the live-born or long-term data of the babies born via IVF/ICSI. The sample size of the study is also too small to evaluate these outcomes. Hence, we cannot evaluate the long-term effects of advanced paternal age on their children, if any. However, multiple studies have shown that advanced paternal age is associated with increased incidence of schizophrenia,35 36 autism,37 38 and genetic conditions such as achondroplasia and Apert’s syndrome, despite young maternal age in their children.39 40 Although the semen parameters analysed were based on the one-off semen sample provided for insemination, semen parameters are known to vary with time. We do not have data on paternal body weight, smoking and drinking habits, medical condition, hormone levels or exact time of abstinence. The range of paternal age was also relatively narrow in this cohort.
 
The present study examined patients who had undergone IVF treatment. This study represents only one subset of infertile patients. Patients undergoing other forms of fertility treatment such as intrauterine insemination would be a valuable subject for further studies.
 
Conclusion
Paternal age is negatively correlated with some semen parameters, which show a significant decline after 40 years. Maternal age, the number of oocytes retrieved, and the number of embryos transferred, but not paternal age are predictive of live birth from IVF treatment.
 
Author contributions
Concept or design: SF Lai, RHW Li, EHY Ng.
Acquisition of data: SF Lai, RHW Li.
Analysis or interpretation of data: SF Lai, RHW Li.
Drafting of the article: SF Lai.
Critical revision for important intellectual content: RHW Li, WSB Yeung, EHY Ng.
 
Funding/support
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
Declaration
All authors have disclosed no conflicts of interest. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Ethical approval
Ethics approval was obtained from the Institutional Review Board of the University of Hong Kong/Hospital Authority Hong Kong West Cluster. Because this retrospective study was carried out using existing patient data in an anonymous manner, the requirement for written informed consent from individual patients was waived.
 
References
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17. Kovac JR, Addai J, Smith RP, Coward RM, Lamb DJ, Lipshultz Li. The effects of advanced paternal age on fertility. Asian J Androl 2013;15:723-8. Crossref
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19. Johnson L, Zane RS, Petty CS, Neaves WB. Quantification of the human Sertoli cell population: its distribution, relation to germ cell numbers, and age related decline. Biol Reprod 1984;31:785-95. Crossref
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Telepsychiatry for stable Chinese psychiatric out-patients in custody in Hong Kong: a case-control pilot study

Hong Kong Med J 2018 Aug;24(4):378–83  |  Epub 27 Jul 2018
DOI: 10.12809/hkmj187217
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Telepsychiatry for stable Chinese psychiatric out-patients in custody in Hong Kong: a case-control pilot study
KM Cheng, MB, BS, FHKAM (Psychiatry)1; Bonnie WM Siu, MB, ChB, FHKAM (Psychiatry)2; Cherie CY Au Yeung, BSc, MStat2; TP Chiang, MB, BS, FHKAM (Psychiatry)1; MH So, BSc3; Mick CW Yeung, FHKAN, BSc3
1 Department of General Adult Psychiatry, Castle Peak Hospital, Tuen Mun, Hong Kong
2 Department of Forensic Psychiatry, Castle Peak Hospital, Tuen Mun, Hong Kong
3 Correctional Services Department, Wanchai, Hong Kong
 
Corresponding author: Dr Bonnie WM Siu (swm810@ha.org.hk)
 
 Full paper in PDF
 
Abstract
Introduction: In Hong Kong, persons in custody receive primary medical care within the institutions of the Correctional Services Department (CSD). However, for psychiatric care, persons in custody must attend specialist out-patient clinics (SOPCs), which may cause embarrassment and stigmatisation. The aim of this interventional pilot study was to compare teleconsultations with face-to-face consultations for a group of stable Chinese psychiatric out-patients in custody.
 
Methods: A total of 86 stable Chinese male out-patients in custody were recruited for psychiatric teleconsultations. They were compared with 249 age-matched Chinese male out-patients in custody attending standard face-to-face psychiatric consultations at other SOPCs. The two groups had comparable baseline characteristics including age, education level, and 12-item Chinese General Health Questionnaire (C-GHQ-12) score. A satisfaction survey of patients towards the teleconsultation was also carried out.
 
Results: Compared with the face-to-face consultation group, the teleconsultation group showed a significantly better result in the difference in C-GHQ-12 scores before and after consultations (P=0.023). The correlation between the first and second teleconsultations also showed a moderate positive relationship (r=0.309). The satisfaction survey showed a favourable response to teleconsultations. No significant adverse events were identified for the teleconsultation group.
 
Conclusions: The results suggest that teleconsultations are a sustainable and safe alternative to face-to-face consultations for stable Chinese psychiatric out-patients in custody.
 
 
New knowledge added by this study
  • Psychiatric teleconsultations are a sustainable and safe alternative to face-to-face consultations for stable Chinese psychiatric out-patients in custody.
Implications for clinical practice or policy
  • The intrinsic problems of embarrassment and stigmatisation caused to persons in custody, their risk of abscondence, and the issue of general public safety can all be addressed with this promising alternative mode of psychiatric care for stable Chinese psychiatric out-patients in custody.
 
 
Introduction
Telepsychiatry is the practice of delivering mental health consultations at a distance. New developments in information and communication technologies have allowed telepsychiatry to become a viable method of providing services to patients in rural or remote locations with limited access to medical services.1 2 3 Telepsychiatry has been used in prison settings for more than 20 years.4 A demonstration of telepsychiatry in prison in the US in 1996 concluded that this practice was cost-effective.5 Prison administrators even claimed that there were fewer assault incidents after its use.5 In Hong Kong, the use of telepsychiatry can be dated back to 1998.6
 
Currently, persons in custody (PICs) in Hong Kong receive primary medical care within the institutions of the Correctional Services Department (CSD). However, for specialist psychiatric service for their mental problems, PICs must attend psychiatric specialist out-patient clinics (SOPCs) of the Hospital Authority. In addition, most psychiatric drugs are available only in SOPCs.
 
For security reasons, PICs must be escorted by at least two CSD staff and be handcuffed on every occasion they need to attend follow-up at a SOPC. Such an exposing arrangement inevitably causes much embarrassment and stigmatisation for PICs. There is also a potential risk to the public in the event of abscondence from custody. The PIC may also experience travel sickness during the journey between the correctional facilities and the SOPC; most correctional facilities in Hong Kong are situated in relatively remote areas, so the journey times can be long. Furthermore, other patients in the SOPC may feel uncomfortable witnessing a PIC being handcuffed. Some SOPCs manage this problem by placing the PIC in a special corner or room, depending on availability.
 
Face-to-face consultation is the gold standard for medical practice. However, telepsychiatry is suitable for PICs and might confer additional benefits for this group of patients. Direct physical examinations are typically unnecessary for stable psychiatric patients during follow-up. Additionally, the nurse at the CSD site can help measure vital signs such as blood pressure, pulse, and temperature. Therefore, offering PICs psychiatric teleconsultations cannot only maintain their usual psychiatric care but also reduce embarrassment, stigmatisation, and the risk of abscondence. Furthermore, it can also reduce the need for special arrangements in SOPCs.
 
To the best of our knowledge, there have been no previous studies exploring the effect of psychiatric teleconsultations for Chinese psychiatric out-patients under the legal custody of the CSD in Hong Kong. The main aim of the present study was to explore the use of psychiatric teleconsultations for stable Chinese psychiatric out-patients under the legal custody of the CSD in Hong Kong. The desired outcome was to maintain the clinical interests of PICs and to provide them with appropriate psychiatric services using telecommunications in a safe, humane, and cost-effective manner. This was an interventional pilot study evaluating the effect of psychiatric teleconsultations on the general health of an intervention group of clinically stable Chinese male psychiatric out-patients who were under the custody of the CSD as compared with a matched control group of Chinese male psychiatric out-patients under the usual type of care (ie, face-to-face consultation with a psychiatrist at a SOPC). In addition, the satisfaction of patients towards psychiatric teleconsultations was assessed.
 
The null hypotheses of this study were as follows:
1. After the consultation, the psychological health of the intervention group is worse than that of the control group;
2. The effect of psychiatric teleconsultations is unsustainable;
3. Patients in the intervention group are unsatisfied with the psychiatric teleconsultations;
4. Adverse events occur during psychiatric teleconsultations.
 
Methods
This was an interventional pilot study conducted by the Hospital Authority in collaboration with the Hong Kong CSD.
 
Participants
The study period was from June 2014 to May 2016. Participants were aged 21 to 64 years. The intervention group comprised Chinese patients in custody attending follow-up at the SOPC of Castle Peak Hospital (CPH), Hong Kong. The control group included Chinese patients in custody attending follow-up at other SOPCs in Hong Kong. In this study, only male PICs were included because of logistic and feasibility reasons. Exclusion criteria applied when selecting intervention and control participants for this study included: (a) patients with mental instability or with prominent and recent change/deterioration in mental condition, such as those who were suicidal or homicidal, or who had delirium or acute psychosis; (b) patients who required regular blood tests, such as those taking clozapine; (c) patients requiring other tests/investigations only available in SOPC or Hospital Authority hospitals; (d) patients requiring drug administration in SOPC, such as depot antipsychotics; (e) patients attending SOPC for the first time; or (f) patients with visual or auditory deficits that might impair the ability to interact via video-conferencing. Eligible patients meeting the inclusion criteria were invited to participate in the study. Written informed consent was obtained from the intervention and control participants.
 
Sample size
A sample size of at least 80 participants for the intervention group with an intervention-to-control ratio of approximately 1:3 was adopted in this study. This was an affordable and representative sample size with reference to the number of stable psychiatric out-patients in custody attending follow-up appointment at the SOPC of CPH during the study period.
 
Assessment tools
Socio-demographic and clinical data including age, education level, and principal psychiatric diagnosis according to the 10th revision of the International Classification of Diseases were obtained.7 The intervention and control participants were requested to complete the Chinese version of the 12-item General Health Questionnaire (C-GHQ-12).8 The GHQ is a self-administered test used for evaluating the psychological components of ill health and is helpful in screening for general emotional distress.9 10 The GHQ possesses adequate content validity and construct validity, and good internal consistency has been demonstrated with Cronbach’s alphas ranging from 0.82 to 0.93.9 10 The Chinese and English versions of the GHQ have been adopted for Chinese and non-Chinese subjects, respectively.8 9 10 The C-GHQ-12 consists of 12 items, with each item assessing the severity of a mental problem using a 4-point Likert scale.8 The six positive items were rated from 1 (more than usual) to 4 (much less than usual) and the six negative items from 1 (never) to 4 (much more than usual); thus, a higher score indicates a more severe mental health condition. In this study, the pre-consultation and post-consultation C-GHQ-12 scores for each patient were obtained. The difference between the two scores (ie, the pre-post difference) was used as a proxy measurement of the quality of consultation.
 
The intervention participants were also requested to complete a questionnaire in Chinese designed to measure the patient satisfaction regarding the psychiatric teleconsultation. The questionnaire consisted of nine statements/questions rated according to a 5-point Likert scale, from 1 (strongly agree) to 5 (strongly disagree) or from 1 (very satisfied) to 5 (very dissatisfied). The questionnaire was designed by the authors as there were no available validated Chinese questionnaires suitable for assessing patient satisfaction of telepsychiatry at the time of the study (English translations of the statements/questions in the questionnaire are listed in Table 1).
 

Table 1. Statements and questions in the satisfaction survey questionnaire (English translation)
 
Procedure
The intervention participants were transferred from various CSD institutions to the Lai Chi Kok Reception Centre, Hong Kong, for the psychiatric teleconsultation. On the scheduled day of consultation, the CSD staff brought two portable video-conferencing devices to CPH. Registration was performed only after the device had been checked as functional. All persons in the consultation rooms at the CSD site and at the CPH site were identified to each other prior to the consultation session. Consultation rooms provided at both sites were appropriately set up with particular attention to audio and visual privacy, lighting, backdrop, and gaze angle. A qualified CSD nurse was present in the consultation room at the CSD site together with the patient. There was also a CSD medical doctor at the reception centre during the psychiatric teleconsultation, in case emergency medical treatment was needed. After the consultation, the CSD staff collected the medicine for the patient according to the usual procedures. For the intervention participants, the maximum number of consecutive psychiatric teleconsultations was set as four, after which a face-to-face follow-up consultation must follow. The control participants attended only face-to-face consultations at other SOPCs. Both groups of participants filled in the C-GHQ-12 within 7 days before the consultation and again within 7 days after the consultation. In addition, the intervention participants filled in the satisfaction survey questionnaire after the psychiatric teleconsultation. Any major adverse events, such as medical or psychiatric emergencies, were recorded.
 
Statistical analysis
Descriptive statistics were used to analyse the baseline profile of the participants’ socio-demographic and clinical characteristics as well as pre- and post-consultation C-GHQ-12 scores and satisfaction survey questionnaire responses. Chi squared test and two-samples t test were performed to assess if there were differences in the baseline characteristics between the intervention and control participants. A non-parametric Mann-Whitney U test was performed to test if there were differences in the pre-post difference in C-GHQ-12 score between intervention and control participants attending their first consultation. Spearman’s correlation was used to compute the correlation between the pre-post difference in C-GHQ-12 score of the first and second teleconsultations among the intervention participants. All statistical analyses were conducted using SPSS for Windows, version 12.0 (SPSS Inc, Chicago [IL], US), with P<0.05 considered as statistically significant in this study.
 
Results
During the study period, there were 377 PIC scheduled attendances at CPH. Of these, 221 PIC scheduled attendances were suitable for psychiatric teleconsultation; however, for 49 of the suitable PIC scheduled attendances, the PICs refused to give consent for this study. Finally, 172 PIC psychiatric teleconsultation attendances were included. Each participant could have more than one psychiatric teleconsultation attendance during the study period. Therefore, 86 participants aged 21 to 64 years who were stable Chinese male psychiatric out-patients and who fulfilled the inclusion and exclusion criteria for psychiatric teleconsultations in CPH were included. For the control group, 249 male patients within the same age range (21-64 years) were recruited.
 
Table 2 compares patient characteristics between the intervention and control groups. There were no significant differences in the age and education profile between the two groups. The mean age of both groups was approximately 40 years. Approximately three quarters of the participants in each group had attained education at the secondary level or above. There was a significant difference in the principal psychiatric diagnosis (P=0.029). Slightly over 50% of each group were diagnosed as substance abuse. A larger proportion of intervention participants had schizophrenia (28%) than did the control participants (16%). There were no significant differences in the mean pre-consultation C-GHQ-12 score between the two groups.
 

Table 2. Demographic and clinical characteristics of participants in the intervention and control groups*
 
The mean (standard deviation) on-air time duration of the psychiatric teleconsultations was 6.33 (3.58) minutes. There were no significant adverse events associated with teleconsultations reported during the study. The pre-post difference in C-GHQ-12 score of the intervention participants was significantly higher than that of the control participants (P=0.023; Table 2). Furthermore, among 29 intervention participants who had at least two teleconsultations, the association between pre-post difference in C-GHQ-12 score of the first and second teleconsultations was moderately strong (r=0.309, P=0.103) but did not reach the level of significance set for this study. The possible scores on the satisfaction survey questionnaire ranged from 9 (the most satisfied) to 45 (the least satisfied). The mean (standard deviation) satisfaction score of the intervention group was 16.48 (4.35). No major adverse events were reported throughout the study.
 
Discussion
Telepsychiatry is not a new development in Hong Kong. Since 2001, the use of telepsychiatry has been shown to increase access to care.11 Studies have shown that telepsychiatry is an effective means to provide psychogeriatric services to residents of care homes,11 and cognitive intervention for community-dwelling elderly patients with memory problems.12 This was the first intervention pilot study in Hong Kong exploring the effect of psychiatric teleconsultation for Chinese psychiatric out-patients under the legal custody of the CSD. Our study compared the effectiveness of psychiatric teleconsultations with that of face-to-face consultations among PIC receiving out-patient psychiatric treatment. The two groups of stable Chinese male out-patient participants had the same baseline characteristics in age, education level, and pre-consultation C-GHQ-12 score. The results showed that the standard of care of teleconsultations was comparable to that of face-to-face consultations. The pre-post difference in C-GHQ-12 score for teleconsultations had a marginally larger positive increase than did face-to-face consultations. The intervention participants also showed high satisfaction with the psychiatric teleconsultation service, with a mean satisfaction score above the 80th percentile. This results is similar to that of a previous study in the US that compared the effectiveness of telepsychiatry and in-person psychiatry sessions among 71 parolees over a 6-month follow-up period, revealing high satisfaction with telepsychiatry treatment.13 In the present study, the pre-post difference between C-GHQ-12 score of the first and second psychiatric teleconsultations showed a moderate positive relationship, suggesting a consistent and sustainable clinical effect of telepsychiatry between sessions. Importantly, there were no reports of significant adverse events. Therefore, telepsychiatry can be considered sustainable and safe for Chinese PIC in Hong Kong.
 
Studies on the effects of telepsychiatry for incarcerated populations are relatively scarce; however, the results of our study are also consistent with studies of telepsychiatry in populations that were not involved with the correctional system. In a randomised controlled study in Canada, 495 patients were assigned at random to be examined face-to-face or by telepsychiatry.14 Psychiatric consultations and follow-ups delivered by telepsychiatry produced clinical outcomes equivalent to those achieved when the service was provided face-to-face.14 This result suggests that psychiatric consultation and short-term follow-up can be as effective when delivered by telepsychiatry as when provided face-to-face. Another study evaluating the effectiveness of telepsychiatry in relation to cognitive changes in patients with dementia revealed that changes in the Mini-Mental State Examination score were not significantly different between patients receiving teleconsultations and those receiving clinic-based face-to-face consultations.15 This finding suggest that telepsychiatry may be a useful alternative to face-to-face clinical visits for treatment of a wide range of patient groups, including patients with dementia. Research has shown that there is an association between dementia and criminal offences and that the use of telepsychiatry might be extended to PIC with dementia in Hong Kong.16
 
Our study has several limitations. First, the sample size of the intervention group was small. Most enrolled patients served short sentences but had long follow-up intervals, because we recruited stable patients. Although the study duration was 2 years, only 29 out of 86 intervention participants had at least two psychiatric teleconsultations for comparison within the intervention group. Second, recruitment of potential telepsychiatry participants was limited to stable Chinese male psychiatric out-patients. Therefore, the sample may be affected by self-selection bias, because PICs volunteered to participate in telepsychiatry. This restricted sample also limits the generalisability of the results. Third, the mean time between the consultation and completion of the C-GHQ-12 was not recorded for intervention or control groups. Differences in this time interval may affect the pre-post difference in C-GHQ-12 score for the groups. We also did not collect data on the follow-up interval between the first and second psychiatric teleconsultations for the intervention group. This follow-up interval may affect the C-GHQ-12 score and the satisfaction on psychiatric teleconsultation. Fourth, the mean on-air time duration of psychiatric teleconsultations was 6.33 minutes; however, we did not measure the duration of face-to-face consultations for comparison between the two groups. The duration of consultation may have an effect on the outcome scores and patient satisfaction. Last, the study lacked robust clinical outcome measures and the satisfactory questionnaire adopted in this study had not been validated. Despite the limitations of this study, the results suggest that psychiatric teleconsultations are a sustainable and safe alternative to face-to-face consultations for stable Chinese male psychiatric out-patients in custody. The use of psychiatric teleconsultations has potential in other populations of PICs, such as female PICs or elderly PICs, but further research is required to investigate psychiatric teleconsultations for these populations.
 
Further research is required to examine the full potential of telepsychiatry among PICs in Hong Kong. In future studies, female patients should be recruited, to assess any sex-based differences. In addition, the scale of future studies using telepsychiatry can be increased by setting up more stations at CSD institutions and at other SOPCs in the Hospital Authority. Clinical outcomes such as symptom severity and psychological functioning of the patients could be assessed. Given the increasing number of older PICs in Hong Kong, recruitment of older patients could be considered for further study. It would be worthwhile to perform a future study with a larger sample size and with participants receiving a greater number of psychiatric teleconsultations, in order to further support the sustainability of psychiatric teleconsultations.
 
A cost analysis for psychiatric teleconsultation was beyond the scope of the present study. However, a systematic review of 137 telemedicine services in hospital facilities revealed that one of the key reasons for introducing telemedicine was cost reduction.17 Similar cost-saving conclusions have been reported in two studies in Hong Kong related to dementia and community geriatric services.11 12 In future studies, cost analysis of psychiatric teleconsultation including direct, indirect, and hidden costs could be calculated for further exploring the effectiveness of psychiatric teleconsultation.
 
Conclusions
Telepsychiatry appears to be an acceptable approach for providing out-patient psychiatric care for stable Chinese male PICs in Hong Kong. Telepsychiatry can be considered a sustainable and safe alternative to face-to-face consultations, with a comparable standard of care. Moreover, the intrinsic problems of embarrassment and stigmatisation caused to PICs, the risk that PICs might abscond, and the safety of the general public are all addressed by this promising alternative mode of psychiatric care for stable Chinese male PICs. Telepsychiatry is likely to show similar benefits for Chinese female PICs and PICs in other age-groups, such as older adults, but further research is required to confirm this.
 
Author contributions
All authors have made substantial contributions to the concept and design, acquisition of data, analysis and interpretation of data, drafting and critical revision for important intellectual content of the article.
 
Acknowledgement
We would like to acknowledge Dr CK Tung, Dr CF Tsui, Mr KW Chung, Mr Kenny Wong, Dr NM Kwong, and all the mental health professionals and CSD staff who have assisted in the design and implementation of this study. We would also like to acknowledge the study participants who had kindly participated in the present study.
 
Funding/support
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
Declaration
All authors have disclosed no conflicts of interest. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity. The research was presented in part in the Hospital Authority Convention 2017, 16 May 2017, Hong Kong.
 
Ethical approval
Approval for conducting the study was granted by the Research and Ethics Committee of the New Territories West Cluster of the Hospital Authority and the Research and Ethics Committee of the Correctional Services Department. The principles outlined in the Declaration of Helsinki were followed in the conduction of this study.
 
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17. AlDossary S, Martin-Khan MG, Bradford NK, Smith AC. A systematic review of the methodologies used to evaluate telemedicine service initiatives in hospital facilities. Int J Med Inform 2017;97:171-94. Crossref

Mesh-related complications from reconstructive surgery for pelvic organ prolapse in Chinese patients in Hong Kong

Hong Kong Med J 2018 Aug;24(4):369–77  |  Epub 31 Jul 2018
DOI: 10.12809/hkmj177173
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Mesh-related complications from reconstructive surgery for pelvic organ prolapse in Chinese patients in Hong Kong
Osanna YK Wan, MRCOG, FHKAM (Obstetrics and Gynaecology); Symphorosa SC Chan, MD, FHKAM (Obstetrics and Gynaecology); Rachel YK Cheung, FHKAM (Obstetrics and Gynaecology), FHKCOG; Tony KH Chung, MD, FRCOG
Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
 
Corresponding author: Dr Osanna YK Wan (osannawan@cuhk.edu.hk)
 
 Full paper in PDF
 
Abstract
Introduction: Mesh-related complications from reconstructive surgery for pelvic organ prolapse are of international concern. The present study aimed to review the incidence, management, and surgical outcomes of mesh-related complications in a Chinese population compared with existing studies involving Western populations.
 
Methods: This was an analysis of a prospectively collected cohort. Laparoscopic sacrocolpopexy, laparoscopic hystercolposacropexy, or transvaginal mesh surgery were offered with or without concomitant vaginal hysterectomy or continence surgery. Patients were followed up and mesh-related complications were noted.
 
Results: Overall, 276 Chinese women who received mesh surgery were included for data analysis. There were 22 mesh-related complications found during a mean follow-up period of 40 months. Mesh exposure accounted for 20 these complications; significantly more occurred after transvaginal than after abdominal mesh surgery (16 vs 4; P=0.01). Median duration from primary operation to the time of mesh exposure detection was 12 months (interquartile range=4.8-32.8 months). Ten patients required surgical excisions of exposed mesh. The re-operation rate after mesh complications was 6.7% (9/134) for transvaginal mesh surgery and 1.4% (2/142) for laparoscopic sacrocolpopexy (P=0.03). All excisions were performed transvaginally and 95% remained well after surgery. Occurrence of mesh exposure was higher in transvaginal mesh surgery (adjusted odds ratio=6.1; P=0.008), in sexually active patients (adjusted odds ratio=5.4; P=0.002), and in obese patients (adjusted odds ratio=3.7; P=0.046). Over 90% were satisfied with the outcome, regardless of mesh complications.
 
Conclusions: The rates of mesh exposure and re-operation were consistent with those reported in the literature, suggesting no significant differences in outcome between Chinese and Western patients for this type of surgery.
 
 
New knowledge added by this study
  • This is among the first studies to report the intermediate incidence and management outcomes of mesh-related complications in the Chinese population in Hong Kong.
  • Transvaginal mesh surgery, coital activity, and obesity were associated with a higher rate of mesh exposure and subsequent need of re-operation.
  • Vaginal excisions of exposed mesh were usually successful; this can be done as an out-patient procedure with satisfactory outcome.
  • A high satisfaction rate (97%) was noted.
  • Dyspareunia and pelvic pain were rare complaints among Chinese women after mesh surgery, despite being common in Western populations.
Implications for clinical practice or policy
  • The rates of mesh exposure and re-operation for mesh-related complications tended to be lower for abdominal mesh surgery than for transvaginal mesh surgery, although the latter is less invasive and has a shorter operating time.
  • Careful selection of patients, ie, patients with advanced stage of pelvic organ prolapse, older than 65 years, and sexually inactive, would benefit more from selecting transvaginal mesh surgery.
  • Weight optimisation before operation may reduce mesh-related complications due to obesity.
 
 
Introduction
Traditional repair of pelvic organ prolapse has a high recurrence risk of up to 30%, leading to development of mesh that decreases anatomical recurrence.1 2 3 However, there has been recent public interest and media reports on adverse events experienced by women after mesh reconstructive surgery, especially in Western populations.4 5
 
Sacrocolpopexy was formerly the gold standard treatment for apical compartment or vaginal vault prolapse and had adequate evidence and support.3 6 However, sacrocolpopexy has a longer learning curve and operating time than vaginal surgery.3 7 Transvaginal mesh surgery was promoted as a good alterative option in terms of anatomical correction and shorter operative time.3 7 8 A previous report on transvaginal mesh surgery for pelvic organ prolapse showed a high rate of patient satisfaction and success in the Chinese population in Hong Kong.9 The incidence of mesh exposure has been reported to be 2% to 12% in sacrocolpopexy,1 2 10 11 and 2.7% to 24% in transvaginal mesh surgery.12 13 14 15 Most reports, including those from the United States Food and Drug Administration4 and the New Zealand Accident Compensation Corporation,5 have involved patients from Western countries and have advised caution regarding the use of transvaginal mesh. There is limited information on transvaginal mesh surgery in Asian populations. Ethnic differences have been suggested as a significant factor for explaining differences in prevalence of pelvic organ prolapse and in pelvic organ mobility.16 17 Possible differences in response and complications from mesh surgery in different populations may exist.
 
Some studies have reported that mesh exposure usually occurs in the first few months after surgery13 14 18 19 but studies with a longer follow-up are required to confirm this. Most studies reporting mesh complications have focused on the time interval between insertion of mesh and excision of the exposed mesh instead of detection of mesh exposure.20 21 The exact location and size of the mesh exposure are sometimes inadequately reported.14 20
 
Many studies have investigated mesh-related complications from mesh reconstructive surgery for pelvic organ prolapse. However, there is limited information on such complications in Asian populations. The aim of the present study was to evaluate the incidence, management, and surgical outcomes of mesh-related complications from mesh reconstructive surgery for pelvic organ prolapse in a tertiary centre in a Chinese population in Hong Kong.
 
Methods
The present study was an observational cohort study conducted at the urogynaecology training centre at the Prince of Wales Hospital, Hong Kong. All patients receiving mesh reconstructive surgery for pelvic organ prolapse between 2005 and 2016 in the study centre were recruited. Those who did not return for any postoperative follow-up were excluded from the data analysis.
 
Laparoscopic sacrocolpopexy was offered to patients with vaginal vault prolapse. In patients with stage III/IV uterine prolapse, medically fit and sexually active, the option of concomitant vaginal hysterectomy with laparoscopic sacrocolpopexy was offered. Laparoscopic hystercolposacropexy was performed if patients requested uterine preservation. Transvaginal mesh surgery, either anterior, posterior, or total vaginal mesh, was available to patients with anterior and posterior compartment prolapse, at least stage III or above, who were aged ≥65 years, were more likely sexually inactive, or had recurrence of pelvic organ prolapse after previous sacrocolpopexy/hystercolposacropexy. Transvaginal mesh surgery was also offered with concomitant vaginal hysterectomy or with uterine preservation. Insertion of vaginal mesh in the posterior compartment was not performed after January 2013, after evidence was published that showed no improvement from posterior vaginal mesh compared with native tissue repair alone.22 23 Concomitant continence surgery in terms of mid-urethral sling or laparoscopic colposuspension was performed if patients had urodynamically confirmed stress incontinence. All operations were performed by urogynaecologists or by urogynaecology subspecialty trainees under direct supervision by urogynaecologists. All demographic data, intra-operative findings, and immediate postoperative events were documented in the patients’ medical records.
 
Patients were followed up at 2 to 4 months and 12 months after surgery, then annually after that. Earlier follow-up was offered if the patient requested. During the follow-up consultation, the attending gynaecologist asked patients about vaginal bleeding, pain, dyspareunia, and the severity of any present symptoms. Vaginal examination was performed to determine whether there was recurrence of pelvic organ prolapse or mesh exposure, as recommended by International Continence Society (ICS) and the International Urogynecological Association (IUGA).24 25 Patients were asked to subjectively assess the treatment outcome during every postoperative clinic visit. Patients rated the outcome as “worse, same, or better” compared with their preoperative condition. Location, size, and area of mesh exposure were documented. Complications related directly to the insertion of mesh were classified according to the joint project of the IUGA and the ICS during the analysis of the database.24 Vaginal oestrogen cream was offered to patients with mesh exposure if not contra-indicated.26 The option of conservative management or surgical excision of exposed mesh was discussed with patients, depending on the severity, symptoms, and their wishes. Treatment outcome with or without mesh-related complications was also studied. All patients underwent the same study protocol and had the same postoperative assessment on mesh complications according to a standardised datasheet. The postoperative assessment was carried out by urogynaecologists or trained gynaecologists.
 
Different variables were studied to investigate any association with mesh complications. Patients were evaluated according to whether they received abdominal or transvaginal mesh surgery.
 
Statistical analyses
Data were analysed using the SPSS Windows version 22.0 (IBM Corp, Armonk [NY], United States). Descriptive analysis was used to study the demographics and incidence of mesh complications. Fisher’s exact test, Chi squared test, student’s t test, and Mann-Whitney U test were used for statistical comparisons between different study groups. A P value of <0.05 was considered statistically significant. Multiple logistic regression was performed for variables found to be statistically significant in univariate analysis; odds ratio (OR) and 95% confidence interval (CI) were also studied.
 
Results
A total of 280 Chinese women received mesh reconstructive surgery from March 2005 to December 2016. Four patients were lost to follow-up. Therefore, 276 (98.6%) patients were included for data analysis (Fig).
 

Figure. Recruitment and data analysis of patients according to route of mesh surgeries
 
The demographics and background data of the study population are presented in Table 1. Abdominal mesh surgery and transvaginal mesh surgery, all with concomitant pelvic floor repair, were performed in 142 and 134 patients, respectively. Concomitant continence operation was performed in 81 (29.3%) patients. Mean follow-up duration was 40 ± 1.47 months (range, 1-131 months).
 

Table 1. Patient demographics and study results of mesh-related complications in overall, and abdominal and transvaginal mesh surgeries for pelvic organ prolapse (n=276)*
 
Mesh-related complications were identified in 22 (8.0%) patients, including vaginal mesh exposure in 20 (7.2%) patients and intra-operative and perioperative complications in one (0.4%) patient each (Table 2).
 

Table 2. Summary of mesh-related complications (n=276)
 
Intra-operatively, there was one bladder injury during insertion of inferior trocar of the anterior vaginal mesh. The involved trocar was immediately removed and re-inserted in another correct surgical plane. Cystoscopy showed a small site of bladder perforation without active bleeding nor urine leakage. No repair was necessary. No mesh material was seen inside bladder. The patient recovered uneventfully without other mesh-related complications in subsequent follow-up.
 
Perioperatively, one patient had mesh infection after anterior vaginal mesh repair with abscess formation in the vulva, requiring mesh removal 18 days after the primary operation. The infection subsided with antibiotics and drainage, but the patient passed away at 7 weeks postoperatively due to other medical morbidities.
 
The incidence of mesh exposure was 2.8% in abdominal and 11.9% in transvaginal mesh surgery (Table 2). Mesh exposure was most commonly found in posterior vaginal wall (33.3%) followed by anterior vaginal wall (27.8%), middle part of vaginal vault (22.2%), left and right vaginal vault (16.7%). The mean ± standard deviation size of the exposed mesh was 1.2 ± 0.6 cm (range, 0.3-2 cm). Median duration from primary operation to the time of first detection of mesh exposure was 12 months (interquartile range [IQR]=4.8-32.8 months); the longest duration was 63 months. Median time of detection was 11.5 months (IQR=5.8-31.8 months) in transvaginal mesh surgery and 34.5 months (IQR=15.0-59.0 months) in abdominal mesh surgery (P=0.081; Table 2). All patients with mesh exposure presented with intermittent vaginal spotting and all involved only the vaginal epithelium. None complained of dyspareunia, or vaginal or pelvic pain, although half of them were sexually active.
 
Vaginal oestrogen cream was given to all 20 patients with mesh exposure; this treatment was successful in eight (40%) patients. Two others were asymptomatic and opted for conservative management. The remaining 10 required surgical excision of the exposed mesh. The main indication for re-operation was vaginal spotting; no re-operations were related to pelvic pain or dyspareunia. All surgical excisions of exposed mesh were performed vaginally under local anaesthesia on the same day, except for one patient who opted for general anaesthesia. The median time between primary operation to first surgical excision of exposed mesh was 14 months (IQR=8.8-37.3 months); the longest was 66 months. Mean ± standard deviation operating time for the surgical excisions of exposed mesh was short, around 20 ± 6 minutes (range, 10-30 minutes) with estimated blood loss of 2 to 10 mL. Three patients required repeated excisions with operating times of 22 ± 2 minutes (range, 20-23 minutes) and estimated blood loss of 7 to 12 mL. Another three, in whom mesh exposure remained after first excision, opted not to have a second excision because they were asymptomatic. Most (95%) patients were well at their latest follow-up. Clinical details of all the mesh-related complications are listed with IUGA/ICS codes24 in Table 3.
 

Table 3. List of IUGA/ICS system CTS codes and clinical details of mesh-related complications
 
The relationships between various factors and mesh exposure were explored (Table 4). Mesh exposure was more common in transvaginal than in abdominal mesh surgery (OR=4.7; 95% CI=1.5-14.3; P=0.007). Transvaginal mesh with posterior insertion was found to be associated with increased risks of mesh-related complications (OR=4.3; 95% CI=1.6-11.5; P=0.002). Total vaginal mesh surgery was also found to be a significant factor (OR=5.0; 95% CI=1.8-13.6; P=0.002). Coital activity (OR=2.8; 95% CI=1.1-6.9; P=0.03) and obesity (OR=4.7; 95% CI=1.5-14.4; P=0.007) were also found to be associated with mesh exposure. No other factors studied were associated with mesh exposure (Table 4).
 

Table 4. Different variables relating to mesh exposure (n=276)
 
Multiple logistic regression was performed on these significant variables. This revealed that transvaginal mesh surgery (adjusted OR=6.1; 95% CI=1.6-16.1), coital activity (adjusted OR=5.4; 95% CI=1.8-16.1), and obesity (adjusted OR=3.7; 95% CI=1.0-13.3) remained the significant factors associated with mesh exposure (Table 4).
 
Discussion
Our study aimed to evaluate the incidence of mesh-related complications from mesh reconstructive surgery for pelvic organ prolapse and associated surgical outcomes in a tertiary unit over the past 11 years. This objective was fulfilled with the study carried out according to its initial design.
 
The main mesh-related complication reported was vaginal mesh exposure, which is consistent with previous studies on mesh-related complications.2 4 20 The findings in this study concur with other reports that the most important risk factor of mesh exposure is route of surgery.11 20 Total vaginal mesh repair was associated with a higher rate of mesh exposure than was anterior vaginal mesh insertion, in agreement with a previous study.13 The posterior vagina was the most common site of mesh exposure in the present study; therefore, avoiding posterior vaginal mesh repair might reduce the incidence of mesh exposure. A lower rate of mesh exposure from transvaginal mesh surgery is expected in future if insertion of posterior vaginal mesh is stopped; studies will be required to confirm this.
 
The rates of mesh exposure in transvaginal mesh surgery and in laparoscopic sacrocolpopexy in the present study were within the range of rates reported in the literature. The re-operation rates for mesh-related complication were similar to those reported in other studies: 2% to 13.2% for transvaginal14 20 and 1.3% to 5% for abdominal mesh surgery.1 20 26 All mesh surgeries in the present study were performed by or with trained urogynaecologists, but that might not be the case in other hospitals.14 20 21
 
Coital activity was associated with higher risks of mesh exposure, in agreement with other study populations.12 18 20 Obesity is known to have many implications for health, including as an independent risk factor for perioperative surgical site infection in vaginal surgery,27 although this is not mentioned specifically in other studies on mesh-related complications. Patients ought to be counselled to attempt weight reduction before a prolapse operation because weight loss might lower the risk of mesh-related complications, in addition to the general benefits of maintaining a body mass index in the normal range.
 
Dyspareunia, pelvic, or vaginal pain are among the most common distressing symptoms reported in the literature4 11 20 21 but these were not reported in this study cohort. This might be explained by differences in the interpretation of ‘discomfort’ from mesh-related complications between Chinese and Western populations.
 
The median time between surgery and detection of mesh exposure in the present study was within the range reported in other studies.12 13 17 18 Mesh exposure tended to be found earlier in transvaginal than abdominal mesh surgery, but this difference was not significant. Patients should be informed about the possible symptoms of mesh exposure and advised to seek medical advice should they experience them.
 
There was one mesh infection with abscess formation and one mild bladder injury over the 11 years of study. Otherwise there were no serious mesh-related complications, such as mesh exposure to the bladder or bowel, or spondylodiscitis.15 19 21
 
Demographic differences were found between the two groups of patients receiving abdominal and transvaginal mesh surgery due to the different selection criteria, as anticipated from the beginning of the study design. Younger patients tend to have higher risks of re-interventions from mesh surgery.28 29 Thus, younger patients are more often offered abdominal instead of vaginal mesh surgery.
 
Concomitant vaginal hysterectomy and concomitant continence surgery were not associated with mesh complications in this study, consistent with one review on abdominal sacrocolpopexy10 but in contrast to another.11 Smoking has been found to be associated with mesh exposure.12 However, the prevalence of smoking was low in this cohort and this association was not detected. Different ages have been found to be associated with higher risk of mesh exposure in other studies,20 26 but this was not confirmed in the present study population.
 
Strengths
The objective was clearly defined and fulfilled. The loss to follow-up rate was low (only 1.4%) and data collection was complete without missing data, reducing possible bias in results analysis. The high follow-up rate could be due to the low medical cost for follow-up and geographical convenience in Hong Kong. A search of the literature suggests that the present study is among the first with a low loss-to-follow-up rate investigating the incidence of mesh-related complications from mesh reconstructive surgery in a Chinese population.
 
Limitations
The 11-year duration of the present study, although long, could be too short for all complications or recurrences of mesh exposure to become apparent. No power calculation was used, because patients only with an advanced stage of pelvic organ prolapse are be offered mesh surgeries, and not all women with advanced pelvic organ prolapse opt for mesh surgery, knowing the possible risks. This study might be underpowered to detect other possible factors associated with mesh complications. However, this study can provide important information on the complications associated with mesh surgeries from a population that has not been well investigated.
 
This was a single-centre study with specific selection criteria for different routes of mesh surgery. All types of mesh surgery for pelvic organ prolapse were performed by the urogynaecology team; this might limit the generalisability of the results to other centres in which operations are performed by non-urogynaecologists.14 20 21 However, it is common practice in other study centres in Hong Kong for urogynaecologists or gynaecologists experiences in vaginal surgery to perform mesh surgery for pelvic organ prolapse.
 
The IUGA/ICS coding24 for mesh-related complications was performed retrospectively during database analysis. However, all data needed for the coding were available. Finally, the follow-up assessment was performed by the same team of surgeons; this might lead to potential reporting bias (on the part of the patient and the clinician). However, the reporting of mesh exposure or complication was an objective clinical decision, with the use of a standardised datasheet and would not be largely affected.
 
Conclusions
Careful selection of patients and intensive training for surgeons would help to reduce the incidence of mesh-related complications from reconstructive surgery for pelvic organ prolapse. The present study found that the incidence of mesh-related complications and the re-operation rate after mesh surgery in Chinese women were consistent with those reported in the Western populations. The incidence of mesh-related complications tended to be lower after abdominal than after transvaginal mesh surgery. Pelvic pain and dyspareunia were rare complaints independent of the occurrence of mesh complications. Surgical outcomes after mesh surgery were satisfactory despite some cases of mesh exposure. Longer-term studies with more patients are needed before definitive conclusions can be drawn.
 
Author contributions
Concept or design: OYK Wan, SSC Chan, RYK Cheung.
Acquisition of data: OYK Wan, SSC Chan.
Analysis or interpretation of data: OYK Wan.
Drafting of the article: OYK Wan.
Critical revision for important intellectual content: SSC Chan, RYK Cheung, TKH Chung.
 
Funding/support
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
Declaration
The authors have no conflicts of interest to disclose. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity. Part of this study was presented as a poster at the International Continence Society 47th Annual Meeting in Florence, Italy, 12-15 September 2017.
 
Ethical approval
Ethical approval was obtained from local institute (The Joint Chinese University of Hong Kong–New Territories East Cluster Clinical Research Ethics Committee) [CREC 2015.125].
 
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