Comparison of different intubation techniques performed inside a moving ambulance: a manikin study

Hong Kong Med J 2014 Aug;20(4):304–12 | Epub 6 Jun 2014
DOI: 10.12809/hkmj134168
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Comparison of different intubation techniques performed inside a moving ambulance: a manikin study
KB Wong, MB, BS1; CT Lui, MB, BS, FHKAM (Emergency Medicine)1; William YW Chan, BSc (Hons), MScPEC1,2; TL Lau, MBA, B Bus (HRM)2; Simon YH Tang, FRCSEd, FHKAM (Emergency Medicine)1; KL Tsui, FRCSEd, FHKAM (Emergency Medicine)1,2
1 Department of Accident and Emergency, Tuen Mun Hospital, Tuen Mun, Hong Kong
2 Auxiliary Medical Service, AMS Headquarters, 81 Princess Margaret Road, Hong Kong
 
Corresponding author: Dr KL Tsui (tsuikl@ha.org.hk)
 Full paper in PDF
Abstract
Objective: Airway management and endotracheal intubation may be required urgently when a patient deteriorates in an ambulance or aircraft during interhospital transfer or in a prehospital setting. The objectives of this study were: (1) to compare the effectiveness of conventional intubation by Macintosh laryngoscope in a moving ambulance versus that in a static ambulance; and (2) to compare the effectiveness of inverse intubation and GlideScope laryngoscopy with conventional intubation inside a moving ambulance.
 
Design: Comparative experimental study.
 
Setting: The experiment was conducted in an ambulance provided by the Auxiliary Medical Service in Hong Kong.
 
Participants: A group of 22 doctors performed endotracheal intubation on manikins with Macintosh laryngoscope in a static and moving ambulance. In addition, they performed conventional Macintosh intubation, inverse intubation with Macintosh laryngoscope, and GlideScope intubation in a moving ambulance in both normal and simulated difficult airways.
 
Main outcome measures: The primary outcome was the rate of successful intubation. The secondary outcomes were time taken for intubation, subjective glottis visualisation grading, and eventful intubation (oesophageal intubation, intubation time >60 seconds, and incisor breakage) with different techniques or devices.
 
Results: In normal airways, conventional Macintosh intubation in a static ambulance (95.5%), conventional intubation in a moving ambulance (95.5%), as well as GlideScope intubation in a moving ambulance (95.5%) were associated with high success rates; the success rate of inverse intubation was comparatively low (54.5%; P=0.004). In difficult airways, conventional Macintosh intubation in a static ambulance (86.4%), conventional intubation in a moving ambulance (90.9%), and GlideScope intubation in a moving ambulance (100%) were associated with high success rates; the success rate of inverse intubation was comparatively lower (40.9%; P=0.034).
 
Conclusions: En-route intubation in an ambulance by conventional Macintosh laryngoscopy is superior to inverse intubation unless the cephalad access is impossible. GlideScope laryngoscopy appears to be associated with lower rates of eventful intubation in difficult airways and has better laryngoscopic view versus inverse intubation.
 
 
Click here to watch a video of different intubation techniques
 
New knowledge added by this study
  • The intubation success rates with conventional Macintosh laryngoscopy in static and moving ambulances were high.
  • The high failure rate and prolonged time associated with inverse intubation technique made it less useful for en-route intubation unless the cephalad access of the patient was not feasible.
  • The study demonstrated high intubation success rate of and slightly longer intubation time with GlideScope intubation in a moving ambulance. GlideScope intubation was associated with lower rates of eventful intubation versus inverse intubation in the setting of difficult airways.
Implications for clinical practice or policy
  • En-route intubation in an ambulance using conventional Macintosh laryngoscopy at a speed of 20 km/h can be considered a viable option, especially when stopping the transport vehicle is impossible and dangerous.
  • The use of video-assisted airway management (GlideScope) could be a backup plan for en-route intubation in the setting of difficult airways, if available.
 
Introduction
Airway management may be required urgently when a patient deteriorates in an ambulance during interhospital transfer or in a prehospital setting. En-route intubation in an ambulance is challenging due to patient and environmental factors.1 These may include inadequate or over-exposed lighting, limited access to the patient, a continuously moving environment, confined space, and unanticipated patient deterioration. The success rate of en-route intubation (89.6%) is lower than that of hospital intubation (98.8%) and intubation-on-scene (94.9%) in air medical transport.2 Intubation success is more likely in a hospital setting (odds ratio [OR]=8.70) or at the scene (OR=2.3) compared with en-route intubation.2
 
Some studies3 4 suggest using inverse intubation in an entrapped or confined environment. In inverse intubation, the intubator crouches or kneels near the patient’s right side, while holding the laryngoscope in the right hand. Patient’s mouth is opened with the intubator’s left hand. The laryngoscope blade is gently pulled up and towards the patient’s feet at a 45° angle. The endotracheal tube is passed between the visualised vocal cords. The success rate and time of intubation of using inverse intubation in air transport were not significantly different from those with conventional intubation in air transport.5 Inverse intubation is particularly useful in circumstances where the cephalad access to the patient is limited. In addition, the mechanical advantages of pulling up the larynx with the dominant hand may, theoretically, facilitate visualisation of vocal cords of patients with difficult airways.
 
In recent years, portable video laryngoscope (GlideScope; Verathon Inc, Bothell [WA], US) was introduced to facilitate airway management in the prehospital setting.6 7 GlideScope was the first commercially available video laryngoscope. It uses a high-resolution camera embedded into a plastic laryngoscope blade, and a LED light for illumination. The distal angulation makes it ideally suitable for visualising and intubating over the anterior larynx. The endotracheal tube has to be used with a special stylet to match the gentle curve of 60° of the GlideScope blade. It has been proven to be a useful adjunct for intubation in both normal and difficult airways in selected settings.8 9 10
 
The objectives of our experimental study were: (1) to compare the effectiveness of conventional intubation by Macintosh laryngoscope in a moving ambulance versus that in a static ambulance; (2) to compare the effectiveness of inverse intubation and GlideScope laryngoscopy (model: GVL 4) with conventional intubation inside a moving ambulance.
 
Methods
Participants
This was a comparative experimental study conducted from June to October 2012. Altogether, 22 doctors—including emergency medicine trainees, members, and fellows—were recruited to participate voluntarily in the study. All participants were working in the accident and emergency department (AED) and had been practising emergency medicine for at least 2 months. All of them had experience in performing endotracheal intubation in patients. The approval of ethics committee was considered waived as the study was performed on manikins and did not involve patients.
 
Demographic data of the participating doctors including age, gender, AED working experience, previous attendance of advanced airway training workshop, past experience of using inverse intubation and GlideScope on living or dead patients were collected. Advanced airway training workshop is a full-day course organised by the Hong Kong College of Emergency Medicine. Course attendants learn the basic skills of endotracheal intubation. Various airway adjuncts such as GlideScope are demonstrated and opportunities provided for participants to practise intubation with these during the course.
 
Pre-experiment preparation
The use of conventional Macintosh laryngoscopy, inverse intubation with Macintosh laryngoscope and GlideScope laryngoscopy were demonstrated to participants individually by the experiment conductor using an “AIRSIM” manikin at least 1 week before the study. The participants were allowed hands-on practice of the techniques and devices, freely, in a training room before the experiment.
 
Experiment setting
The experiment was conducted in an ambulance provided by the Auxiliary Medical Service. The ambulance we used was Mercedes-Benz 516CDI measuring approximately 1.6 m in width and 2.2 m in length. The stretcher, together with the manikin, was locked on the right side of the ambulance, as in real life. The intubator would have limited room to kneel down at the vertex of the patient to perform conventional Macintosh and GlideScope intubations (Fig 1). Inverse intubation was performed on the right side of the manikin (Fig 2). The ambulance was moving at a speed of 20 km/hour, following a fixed route chosen before the experiment within the hospital compound. Moving at this relatively slow speed was only possible on the chosen route as there were a number of turnarounds and road bumpers.
 
 

Figure 1. Intubation in a confined space
 

Figure 2. Inverse intubation performed on the right side
 
Intubation setting
The Laerdal “Adult Basic” manikin was used in the study. A neck collar was applied to the manikin to restrict the neck mobility and simulate a difficult airway. Size-3 blade was used for conventional Macintosh and inverse intubations. All intubations were performed with a 7.5-mm cuffed endotracheal tube. All participants performed intubations on the manikin in both normal and difficult airways inside a static ambulance and moving ambulance. Participants performed the conventional Macintosh, inverse Macintosh and GlideScope intubations in both normal and simulated difficult airways inside the moving ambulance in the same sequence. Neither external manipulation of the larynx nor airway management adjunct was allowed in the study.
 
The time required for intubation was recorded with electronic stopwatch and corrected to one decimal place. The start time was defined when the participant was asked to begin while sitting on the couch, approximately 1 metre from the manikin, with the equipment in hands. The end of the procedure was defined when the participant verbally stated that the airway was secured with inflation of the cuffed balloon of the endotracheal tube. The verification of the endotracheal tube placement was performed by direct visualisation and inflation of the artificial lung, with no air leakage from the manikin. Both oesophageal intubation and intubation with time taken longer than 60 seconds were considered to be unsuccessful procedures. Incisor breakage was reported by the participants when a “click” sound was heard during intubation; however, it was not considered an unsuccessful intubation. Participants also reported the Cormack-Lehane laryngoscopic grading system (C&L grade; grade 1-4) and their preferences for intubation techniques and devices. Eventful intubation was defined as incisor break, oesophageal intubation, or intubation taking longer than 60 seconds.
 
Data analysis
We used SPSS version 16.0 for Windows for statistical analysis. Rates of successful intubation and incisor breakage were presented in percentage. The working experience of participants and time spent on intubation were described by median and interquartile range as the data showed skewed distribution. The time required for intubation by different intubation techniques and devices were analysed by Wilcoxon signed rank test for paired data. The rates of successful intubation, complications including oesophageal intubation, incisor breakage and the subjective visualisation grading system among different intubation techniques and devices were compared using Fisher’s exact test with or without Freeman-Halton extension. Spearman’s correlation was employed to show the relationship between time of intubation and AED experience. The results were regarded as statistically significant if P<0.05.
 
Results
A total of 22 AED (17 male and 5 female) doctors participated in the experiment. The median age of the participants was 30.5 years. The mean AED working experience of the participants was 4.9 years. As the technique and devices were demonstrated by the experiment conductor before beginning the experiment, all doctors had experience with using inverse intubation and GlideScope in a manikin. The details are shown in Table 1. All participants performed intubations in the eight scenarios and the success rate of each scenario was summarised in Figure 3.
 

Table 1. Baseline characteristics of the participant doctors (n=22)
 

Figure 3. Flowchart of the experiment and primary outcomes in the experiment
 
Conventional intubation in static versus moving ambulance
The percentage of successful and unsuccessful intubations, time required for intubation, subjective glottis visualisation score, and complication rates using conventional Macintosh intubation in static and moving ambulance are shown in Table 2. In normal airways, the intubation success rates in both static (95.5%) and moving ambulances (95.5%) were high. The median intubation times for intubation in static and moving ambulances were 21.2 seconds and 26.5 seconds, respectively (P=0.268). In difficult airways, the intubation success rates in static and moving ambulances were 86.4% and 90.9%, respectively. The median intubation times in static and moving ambulances were 22.6 seconds and 20.6 seconds, respectively (P=0.488). There was no significant difference in the Cormack-Lehane grades and incidence of eventful intubation between the two groups.
 

Table 2. Comparison of success rate, intubation time, glottis visualisation grading, and eventful intubation rate with conventional Macintosh intubation in static and moving ambulance
 
Conventional intubation versus inverse intubation in a moving ambulance
The intubation performance using the conventional Macintosh laryngoscopy and inverse Macintosh intubation in a moving ambulance is shown in Table 3. In normal airways, the success rate of conventional intubation (95.5%) was significantly higher than that of inverse intubation (54.5%; P=0.004). The median intubation time with the conventional technique (26.5 seconds) was shorter than that with inverse intubation (37.8 seconds; P=0.043). The number of difficult laryngeal visualisation (ie Cormack-Lehane grade ≥3) was significantly higher with inverse intubation technique (n=8; 36.4%) versus the conventional technique (0%; P<0.001). The incidence of eventful intubation with inverse intubation (81.8%) was significantly greater than that with conventional intubation (13.6%; P<0.001). In difficult airways, the intubation success rate of conventional technique (90.9%) was also significantly higher than that of inverse intubation (40.9%; P=0.034). The median intubation time required for conventional intubation technique (20.6 seconds) was significantly shorter than that for inverse intubation (51.3 seconds; P=0.002). The number of difficult airway intubations was significantly higher with inverse technique (n=12; 54.5%) than with conventional technique (13.6%; P=0.003). The incidence of eventful intubation was significantly higher in the inverse intubation group (81.8%) than that in the conventional intubation group (36.4%; P=0.002).
 

Table 3. Comparison of success rate, intubation time, glottis visualisation grading, and eventful intubation rate with conventional Macintosh and inverse Macintosh intubation in a moving ambulance
 
Conventional intubation versus GlideScope intubation in a moving ambulance
The intubation performance using conventional Macintosh and GlideScope laryngoscopes in a moving ambulance is summarised in Table 4. In normal airways, the conventional intubation technique (95.5%) and GlideScope laryngoscopy (95.5%) were associated with high success rates. The median intubation time with conventional technique (26.5 seconds) was shorter than that with GlideScope (31.0 seconds; P=0.012). In difficult airways, both conventional technique (90.9%) and GlideScope (100%) were associated with high success rates. The median intubation time with conventional technique (20.6 seconds) was significantly shorter than that with GlideScope (32.4 seconds; P<0.001). None of the intubations with GlideScope in both normal and difficult airways was given Cormack-Lehane grade of ≥3 but no statistical difference could be demonstrated in the grades when compared with conventional intubation in both normal (P=0.721) and difficult airways (P=0.180). There was an obvious trend for less eventful intubation with GlideScope (9.1%) versus the conventional intubation group (36.4%; P=0.069).
 

Table 4. Comparison of success rate, intubation time, glottis visualization grading, and eventful intubation rate with conventional Macintosh and GlideScope intubations in a moving ambulance
 
The relationship between the time required for intubation and AED experience is presented in Figure 4. An experienced doctor in AED required less time for conventional intubation in both normal (P=0.043) and difficult airways (P=0.019) in a static ambulance. Also, experienced doctors did better with conventional intubation than inverse intubation in normal airways in a moving ambulance (P=0.019).
 

Figure 4. Correlation between intubation time for performing conventional intubation and working experience in the accident and emergency (A&E) department (a) in a static ambulance in normal airways, (b) in a moving ambulance in normal airways, and (c) in a static ambulance in difficult airways
 
Data on the doctors' perception of the new technique and device were also collected. Overall, two (9.1%) and 17 (77.3%) doctors thought that inverse intubation and GlideScope were, respectively, useful as adjuncts in normal airways, while one (4.5%) and 19 (86.4%) thought that inverse intubation and GlideScope were, respectively, useful in difficult airways.
 
Discussion
Previous studies found a 7% to 10% incidence of difficult intubation in prehospital emergency en-route intubations.11 12 A number of patient and environmental factors contribute towards the difficulty in en-route intubation.1 Environmental factors including restricted space, continuous movement of the ambulance, and inadequate lighting are believed to adversely affect the en-route intubation compared with intubation in a controlled hospital setting. In our study, we found that the success rates of conventional Macintosh intubation in normal and difficult airways were high in static and moving ambulances. There was no significant difference in oesophageal intubation rate, intubation time, laryngeal visualisation scores, and incisor breakage rate with conventional Macintosh intubation in static and moving ambulances. The environment of a moving ambulance did not appear to hinder the ability of conventional Macintosh intubation in our experiment. Gough et al13 also recruited 20 emergency medical technicians at the advanced-intermediate level of EMT (Emergency Medical Technician) to perform intubation on a manikin in a moving ambulance and static station. They also found no significant difference in the success rates and time required for intubation between the two groups. Stopping an ambulance or a helicopter for en-route intubation may be impossible or dangerous in real life. Our study suggests that en-route intubation is feasible in an ambulance moving at a speed of 20 km/hour.
 
Inverse intubation has been proposed by Hilker and Genzwuerker3 as “an important alternative for intubation in the street”. The technique was proven to be useful as adjunct in failed conventional intubation and an important backup position if access from behind the patient’s head is impossible.4 5 14 In our study, we found that inverse intubation in an ambulance was associated with higher failure rate, prolonged intubation, and more complication rates versus conventional intubation. The clinical usefulness of this technique in a moving ambulance was not established in our study. Besides, one of the reported complications of inverse intubation is pharyngeal laceration.15 If this complication is not recognised, it could result in significant haemorrhage or potentially lethal infection. Individual experience is a significant determining factor for the success of the technique. During the experiment, we also found that it was quite inconvenient for the intubators who wore spectacles to perform inverse intubation as the spectacles were likely to fall off due to the peculiar posture required when performing the procedure. Inverse intubation would be a reasonable choice for trained rescuer who cannot position himself/herself to the space above the victim’s (eg entrapment).
 
GlideScope has been shown to facilitate tracheal intubation by improving the laryngeal view in manikin studies,7 8 9 emergency settings,16 17 18 and a wide spectrum of selective surgeries.19 20 21 Struck et al6 conducted a retrospective observational study and survey of experiences in prehospital intubation for a 3-year period. Around 15% of the patients presented with multiple traumas or failed intubation with conventional laryngoscopy and required intubation by GlideScope. In our study, we demonstrated high intubation success and low failure rates with GlideScope laryngoscopy, but the median time for intubation was slightly longer versus that with the conventional Macintosh laryngoscopy in normal airways (P=0.012) and difficult airways (P<0.001). The finding of longer intubation time with GlideScope was also demonstrated in previous studies.16 19 20 However, some studies found no difference in the intubation time.7 22 One study8 even found that GlideScope enables faster intubation in patients with cervical spine immobilisation. The wide range of results may be attributed to the differences in experience with using GlideScope, different study settings (manikin vs real patient), and different study scenarios (normal vs difficult airway). Piepho et al23 conducted a study among paramedics who used the Macintosh and GlideScope video laryngoscopes for intubating manikins. They found that the intubation time with GlideScope was longer than that with Macintosh in the first and second attempts of intubation. However, no significant difference in time required for intubation was observed in the subsequent attempts. This confirms a rapid learning curve for intubation with GlideScope. In another manikin study with 60 anaesthetists, GlideScope was found to have a steep learning curve for intubation but, after five attempts, differences in terms of time of endotracheal intubation persisted when compared with the Macintosh laryngoscopy.24 In our study, there was a trend for less eventful intubation with GlideScope (P=0.069) in the setting of difficult airways. Thus, we recommend its use as a backup for en-route intubation, especially in difficult airway settings. In real-life practice of using GlideScope, the passage of endotracheal tube through the deeply curved and rigid stylet may be hindered. An assistant is required to thread the endotracheal tube into the trachea while the intubator holds the GlideScope in position. This is expected to be more difficult in an ambulance because of limited space.
 
This study had several limitations. Firstly, we used a manikin in our study rather than a real patient; thus, the results may not be transferrable to real patients. However, we believe that the use of new techniques and devices in airway management is not ethical in clinically unstable and emergency patients. A well-designed manikin-based study would be an acceptable choice for the aforementioned reasons. Secondly, only one of the difficult airway situations was tested in our study. Other difficult airway situations in daily practice such as limited mouth opening, tongue oedema, and presence of blood/vomitus were not studied. Thirdly, there was the issue of learning curve associated with new techniques and devices. Overall, one (4.5%) and eight (36.4%) of the participants had previous experience of using inverse intubation and GlideScope in clinical settings, respectively. Although we demonstrated the use of inverse intubation and GlideScope and allowed participants to practise freely at least 1 week before the experiment, we cannot demonstrate the non-inferior result associated with the use of inverse intubation in a previous study.5 We also observed that the intubation time for difficult airways in a moving ambulance was shorter than that for normal airways. The most likely explanation is the learning effect and intubation experience. The participants performed different intubation techniques in normal airways followed by the same techniques in difficult airways in a moving ambulance. The participants may have gained experience from working in a continuously moving environment. We suggest further studies with inverse intubation and GlideScope after a longer period of training and practice to examine for the reproducibility of these results. Fourthly, the study was performed inside our hospital which has imposed speed limits on vehicles moving on the road. Moving at a relatively slow speed of 20 km/hour was only possible in the chosen route as there were a number of turnarounds and road bumpers. Moreover, we limited the speed in order to avoid any danger to or fall of participants. Fifthly, GlideScope (model: GVL 4) for the experiment was chosen because it was the only model available in our hospital. Other models that are specifically designed for prehospital use such as Glidescope Ranger may be a better choice, if available. Lastly, the sample size of the study was relatively small and could have inadequate power to detect real differences between some comparison, for example, comparison of the eventful intubation rate between GlideScope and conventional intubation.
 
Conclusions
Our study demonstrates an overall high intubation success rate with conventional Macintosh and GlideScope laryngoscopes in a moving ambulance. The time required for intubation with GlideScope was longer than that with conventional laryngoscope. Application of GlideScope should be suggested as an adjunct for intubation in an ambulance in the presence of adequately trained staff. The high failure rate and prolonged time associated with the inverse intubation technique make it less useful than conventional intubation and GlideScope intubation unless the cranial access of the patient is restricted.
 
Acknowledgements
We would like to thank the Auxiliary Medical Service, the Hong Kong SAR Government for providing the ambulance and all physicians who participated in this experimental study.
 
References
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Factors associated with intimate partner violence against women in a mega city of South-Asia: multi-centre cross-sectional study

Hong Kong Med J 2014 Aug;20(4):297–303 | Epub 23 May 2014
DOI: 10.12809/hkmj134074
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Factors associated with intimate partner violence against women in a mega city of South-Asia: multi-centre cross-sectional study
Niloufer S Ali, MB, BS, FCPS1; Farzana N Ali, MB, BS2; Ali K Khuwaja, MB, BS, FCPS3; Kashmira Nanji, MSc, BScN1
1 Department of Family Medicine, The Aga Khan University, Karachi 74800, Pakistan
2 Department of Family Medicine and Community Health, University Hospitals Case Medical Center, Ohio 44106, United States
3 Departments of Family Medicine/Community Health Sciences, The Aga Khan University, Karachi 74800, Pakistan
 
Corresponding author: Dr Kashmira Nanji (kashmira.nanji@aku.edu)
 Full paper in PDF
Abstract
Objectives: To assess the proportion of women subjected to intimate partner violence and the associated factors, and to identify the attitudes of women towards the use of violence by their husbands.
 
Design: Cross-sectional study.
 
Setting: Family practice clinics at a teaching hospital in Karachi, Pakistan.
 
Participants: A total of 520 women aged between 16 and 60 years were consecutively approached to participate in the study and interviewed by trained data collectors. Overall, 401 completed questionnaires were available for analysis. Multivariate logistic regression analysis was used to identify the association of various factors of interest.
 
Results: In all, 35% of the women reported being physically abused by their husbands in the last 12 months. Multivariate analysis showed that experiences of violence were independently associated with women’s illiteracy (adjusted odds ratio=5.9; 95% confidence interval, 1.8-19.6), husband’s illiteracy (3.9; 1.4-10.7), smoking habit of husbands (3.3; 1.9-5.8), and substance use (3.1; 1.7-5.7).
 
Conclusion: It is imperative that intimate partner violence be considered a major public health concern. It can be prevented through comprehensive, multifaceted, and integrated approaches. The role of education is greatly emphasised in changing the perspectives of individuals and societies against intimate partner violence.
 
 
New knowledge added by this study
  • This study shows that women’s literacy can play an important role in changing the perspectives of individuals and societies towards violence against women.
  • Substance abuse including smoking and alcohol consumption may directly be responsible for intimate partner violence against women in Pakistan.
Implications for clinical practice or policy
  • The growing understanding of the impact of violence needs to be translated into primary, secondary, and tertiary level prevention, including both services that respond to the needs of women living with or who have experienced violence, and interventions to prevent violence.
  • There is a need for intervention programmes in all societies and cultures for both men and women to highlight this imperative issue.
 
 
Introduction
Intimate partner violence (IPV) against women is a global human rights and public health problem. Addressing violence against women (VAW) is central to the achievement of Millennium Development Goal (MDG) 3 on women’s empowerment and gender equality, as well as MDGs 4, 5, and 6.1 Intimate partner violence is defined as “the range of sexually, psychologically and physically coercive acts used against adult and adolescent women by current or former male intimate partners”.2
 
The two terms, VAW and IPV, are used interchangeably with gender-based violence. It is reported that violence imposed by husbands is the most common form of VAW.3 Data from the World Bank suggest that women aged 15 to 44 years are at greater risk from rape and domestic violence than from cancer, motor accidents, war, and malaria.3 There is enormous body of evidence to suggest that such acts of violence adversely affect the overall wellbeing of women and are associated with psychiatric morbidities like anxiety, depression, addictive behaviour, etc, and physical injuries, sexually transmitted infections, poor reproductive health outcomes, and even death.4 5 6 7 The impact may also span to affect the mental and physical health of children, who may get “caught in the cross fire” and are directly injured or may get less directly affected as a consequence of abusive relationship between parents.8 9
 
Violence against intimate partners occurs in all countries, all cultures, and at every level of society without exception, although some populations (for example, low-income groups) are at greater risk of violence by intimate partners than others.10 In 48 population-based surveys from around the world, 10% to 69% of women reported being physically assaulted by an intimate male partner at some point in their lives.3 The World Health Organization (WHO) multi-country study on women’s health and domestic violence documented lifetime prevalence of physical and/or sexual partner violence among ever-partnered women in the 15 sites surveyed ranging from as low as 15% in an Ethiopian province to as high as 71% in Japan.11
 
The burden of IPV is particularly alarming in developing countries as women are vulnerable to many forms of violence and IPV represents the most common form.
 
The widespread nature of the issue is further evidenced by the findings of more recent studies from countries with varied economic and developmental strata. About 15% of women visiting the family practitioners in Toronto, Canada, admitted being victims of IPV.12 Another study from a developing country reported the prevalence of male partner–perpetrated violence to be around 7%.13 Although a true comparison is difficult to make due to methodological differences between studies, in general, a higher burden of the problem is observed in developing countries, including those from South Asia. Around one third to one half of the female participants in different studies from India accept IPV victimisation.13 14 According to the recent Bangladesh Demographic Health Survey, almost half of married Bangladeshi mothers (42.4%) with children aged 5 years and younger experienced IPV from their husbands.14 Similarly, in Pakistan, nearly one third to one half of the women stated that they are victims of IPV.15 16
 
Although the prevalence of IPV varies across countries, the factors associated with an increased risk of IPV are similar. These may include substance/alcohol use, young age, and attitudes supportive of wife beating. However, higher education status, high socio-economic status, and formal marriage offer protection against IPV.11 17 18
 
Limited data are available from Pakistan on VAW. The topic remains largely inadequately studied despite its far-reaching adverse consequences. Moreover, most of the published studies have been conducted in the same communities or in communities with similar socio-economic backgrounds, skewing the approximate magnitude of the problem to extremes and hampering the analysis of important demographic factors that may be associated with IPV against women. The aim of this study was therefore to estimate the proportion of women subjected to IPV in Pakistan and to examine whether demographic factors such as education status of both wife and husband and husband’s involvement in substance abuse were associated with IPV. We conducted this study among women from diverse socio-economic backgrounds to assess the proportion of women subjected to IPV and the associated factors. We also aimed to determine the attitudes of participants towards the use of violence by husbands.
 
Methods
This cross-sectional study was conducted in four family practice clinics situated in various localities of Karachi, the largest city and economic hub of Pakistan. Karachi is one of the largest metropolitan cities of the world where over 16 million people reside; it is also called mini-Pakistan as its residents represent all the ethnicities, provinces/states, and socio-economic classes. All these clinics are affiliated with a private tertiary care teaching hospital. A total of eight family practice clinics are associated with the teaching hospital and these clinics were included as they provide health services to people from different socio-economic strata (lower, middle, and upper). All participants were assured of complete confidentiality of the information collected. After obtaining consent to participate in the study, currently married women (aged 16-60 years) were interviewed consecutively by four female medical students (each in a clinic) who had received prior training for this task. The data were collected simultaneously in all the clinics from July 2012 to November 2012. Sample size was calculated with the help of WHO software for sample size determination. As the prevalence of VAW ranges between 30% and 50%,14 15 16 we used a prevalence of 50% for maximum variance with an error bound of 5%; this gave a sample size of 385. The sample size was then inflated by 7% for non-respondents to give a final sample size of approximately 412.
 
After extensive literature search and consensus by study investigators, a structured questionnaire was developed and pre-tested. The questionnaire was initially prepared in English, translated into Urdu and then back-translated into English. The final questionnaire was comprised of sections including socio-demographic characteristics and questions regarding the experience of physical/verbal abuse inflicted ever (lifetime) by husband. In this study, physical abuse was defined by any of the following acts used against women: slapping or throwing something at her that could hurt her; pushing or shoving; hitting with fist or something else that could hurt; kicking, dragging, or beating; choking or burning on purpose; and threatening to use or actually use a gun, knife, or weapon against her. The questionnaire also included a section on the women’s attitude towards use of violence by husbands against wives. Questions were also included about other variables of interest which included education status of the woman and her husband, working status of the woman and her husband, years since marriage and total number of children, family system in which the woman lives, and information about smoking status and other addictive substances used by the husband. The time required to complete the questionnaire was about 25 to 30 minutes. Due to the sensitivity of the issue, the interviews were conducted with each participant in separate rooms ensuring full privacy. The study was approved by the Research Committee of the Department of Family Medicine, Aga Khan University, Karachi, Pakistan, and prior permission was sought by administration of study clinics.
 
Data were analysed using the Statistical Package for the Social Sciences (Windows version 19; SPSS Inc, Chicago [IL], US). The proportion of violence experienced by women and other variables of interest were calculated. Cross-tabulation and Chi squared test were used to assess the association between the women’s perception and their level of education. The independent association of factors studied with violence experienced by women was examined by multivariate stepwise logistic regression analysis to obtain odds ratios (ORs) and 95% confidence intervals (CIs). Covariates such as education status of participants, education status of husband, and smoking and substance abuse by husband were included in the multivariate model.
 
Results
A total of 550 women were approached, of which 520 fulfilled the eligibility criteria. As there were 119 women who refused to participate or provided incomplete information in the questionnaire, the response rate was 77%. Finally, information from 401 participants was included in the final analysis; for missing data, we averaged estimates of the variables to give a single mean estimate. The socio-demographic characteristics of the participants are summarised in Table 1. Overall, 190 (47.4%) of the participants were aged 40 years and above, 165 (41.1%) had received no education at all, and husbands of 111 (27.7%) participants had received no schooling. A majority (n=363; 90.5%) of respondents were housewives while one third of the participants’ husbands were not working (jobless or retired from work). Overall, 170 (42.4%) participants had been married for more than 20 years, 265 (66.1%) had three or more children, and 252 (62.8%) were living in nuclear (single) families. Husbands of 132 (32.9%) participants were current tobacco smokers and over one fifth of them consumed addictive substances other than tobacco smoking.
 

Table 1. Distribution of socio-demographic characteristics in participants and the association of these characteristics with reported violence by their husbands (n=401)
 
Overall, 140 (35%) participants reported being ever physically/verbally violated by their husbands in the last 12 months. The factors associated with IPV against women on univariate analysis are summarised in Table 1. These included illiteracy of women, living in a nuclear family, and being married for more than 20 years; factors related to the husband were illiteracy, unemployment, smoking, and use of other substances besides tobacco.
 
In the multivariate analysis (Table 2), four factors were independently associated with IPV against women. These were women’s illiteracy, husband’s illiteracy, smoking habit of husband, and use of substances other than tobacco by husband. Women who were illiterate were 6 times more likely to have been violated by their husbands versus those who were literate (adjusted OR [AOR]=5.9; 95% CI, 1.8-19.6), while women whose husbands were illiterate were 4 times more likely to have been abused than those whose husbands were literate (AOR=3.9; 95% CI, 1.4-10.7). Study participants whose husbands smoked tobacco reported being victims of violence by their husbands 3 times more often than their counterparts (AOR=3.3; 95% CI, 1.9-5.8). Almost similar odds for IPV were observed in participants whose husbands were addicted to substances other than tobacco (AOR=3.1; 95% CI; 1.7-5.7).
 

Table 2. Multivariate analysis for independent factors associated with intimate partner violence among study participants
 
Overall, 268 (67%) participants accepted that a wife should always follow her husband’s instructions irrespective of her will and 74 (18.5%) women agreed that violence against wife was justified if she did not follow her husband’s instructions.
 
The association of women’s perspective towards husband’s dominance and use of violence against wife with the number of years of school attended by women is shown in the Figure. As the number of years of schooling increased, there was a significant decline in the proportion of women who were in favour of husbands’ dominance over wives, and those who accepted violence against wives (Chi squared, P<0.001). The Figure depicts that the majority of the illiterate women (over 75%) agreed that wife should always follow her husband’s instructions irrespective of her will, and about 30% believed that violence against a wife was justified if she did not follow her husband’s instructions. On the other hand, less than 5% of the women who had more than 12 years of education thought that IPV was justified if the husband’s instructions were not followed.
 

Figure. Association of education status with women’s attitude towards intimate partner violence
 
Discussion
Violence against women is being increasingly identified as a major contributor to the ill health and mortality among women.3 10 Despite the imperative nature of the problem, there is lack of adequate information on IPV against women in Pakistan. In the current study, we have explored the proportion of women abused by their intimate partners and have identified factors significantly associated with such acts of abuse.
 
In this study, approximately one third of the women (35%) reported being ever physically/verbally violated by their husbands. Other studies from Pakistan15 16 have also reported similar findings, with approximately one third to one half of the participants experiencing some form of violence from intimate partners. However, a study conducted in Karachi, Pakistan, among 400 married women showed that the prevalence of IPV (physical violence) was 80%.17 A possible explanation for this high magnitude of IPV prevalence could be the fact that the participants were recruited from low socio-demographic background communities that may be associated with increased perpetuation of violence and vulnerability to the victimisation of violence.
 
The education status of both the partners has been observed to have significant influence on the prevalence of IPV.19 20 21 Provision of education undoubtedly plays a protective role against IPV. Empowering women through social networking along with income earning improves their capacity to access information and resources available in society, and seek help in case of spousal abuse.19 The results of the current study also clearly indicate a positive association between the literacy levels of husband and wife and IPV victimisation among women. Education also imparts a protective role through influencing the perspectives of individuals, and societies in general, against the acceptability of mistreatment towards women.19 A climate of tolerance towards IPV makes it easier for perpetrators to persist with their violent behaviour.22 Education inculcates a sense of self-respect and self-reliance in women, enhancing their capacity to make appropriate decisions regarding various aspects of their lives confidently and autonomously.11 On the other hand, lack of education not only deprives women from acknowledging their rights but, instead, stigmatises their thinking on gender roles and makes them more accepting towards use of force to impose these roles.23 24 This effect was observed in previous studies in which low level of education was associated with women’s acceptance of wife battering, whereas higher education level was negatively associated with tolerance of wife beating. Furthermore, educated women were most protected against violence.23 24 This is also reflected in the findings of this study in that acceptance and tolerance towards husband’s mistreatment and control over the wife markedly declined as the education level of the women improved.
 
The results of the current study also indicate that women whose husbands smoke or consume other substances of abuse experience increased levels of IPV. This is consistent with the findings of previous studies20 25 26 which showed that smoking, alcohol consumption, and using other substances of abuse were strongly associated with IPV. Substance abuse, including smoking and alcohol consumption, may be directly responsible for IPV by affecting cognition, reducing self-control, perpetuating aggression and may also induce stress and unhappiness in relationships, thereby, further increasing the risk of violence and conflict.26
 
This study has some limitations. It was conducted in selective family practice clinics which may have underestimated the results due to under-reporting. Since these clinics are situated in urban areas of a single city, the participants may not represent the population at large. Moreover, the response rate was low in this study (77%) due to the sensitive nature of the issue. There is also a chance of selection bias. As this was a cross-sectional study, temporality or causality could not be established. Owing to the cultural and social restrictions, we did not enquire about sexual abuse. Moreover, due to sensitivity of the issue, there may have been under-reporting of such information. We had asked about the abuse ever in the lifetime; therefore, there is some possibility of recall bias as well. Hence, the actual burden of the problem may be higher than what we have reported. Finally, the questionnaire used in this study is not a validated tool, so there is a chance of information bias in the study.
 
Conclusion
In the light of the above findings, it is imperative that VAW be considered a major public health concern. The prevention of VAW can be achieved through comprehensive, multifaceted, and integrated approaches that require joint efforts by the government, policy-makers, social workers, religious scholars, educationalists, and public health practitioners. In this respect, the role of education is greatly emphasised in changing the perspectives of individuals and societies against IPV. Family physicians, being the first-line doctors and health care providers, should be well trained in screening for IPV and providing instantaneous care to the victims by catering to their psychological needs to prevent poor mental health outcomes.
 
References
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Acanthosis nigricans in obese Chinese children

Hong Kong Med J 2014 Aug;20(4):290–6 | Epub 25 Apr 2014
DOI: 10.12809/hkmj134071
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Acanthosis nigricans in obese Chinese children
HY Ng, MB, ChB, MRCPCH; Jack HM Young, MB, ChB, MRCPCH; KF Huen, FHKCPaed, FHKAM (Paediatrics); Louis TW Chan, FHKCPaed, FHKAM (Paediatrics)
Department of Paediatrics and Adolescent Medicine, Tseung Kwan O Hospital, Tseung Kwan O, Hong Kong
 
Corresponding author: Dr HY Ng (nghypatrick@gmail.com)
 Full paper in PDF
Abstract
Objectives: To investigate the demographic characteristics and insulin resistance in local overweight/obese Chinese children with and without acanthosis nigricans, and the associations of acanthosis nigricans with insulin resistance and other cardiometabolic co-morbidities.
 
Design: Case series with cross-sectional analyses.
 
Setting: A regional hospital in Hong Kong.
 
Patients: Chinese children assessed between January 2006 and December 2010 at Tseung Kwan O Hospital for being overweight or obese.
 
Main outcome measures: The demographics, anthropometric data, acanthosis nigricans status, and biochemical results were analysed.
 
Results: A total of 543 overweight/obese children were studied with 64% being boys and 29% had insulin resistance. Adolescents aged 12 to 18 years, compared with children aged 5 to 11 years, were more likely to have acanthosis nigricans (63% vs 47%; P<0.001) and insulin resistance (37% vs 25%; P=0.005). Compared with overweight children, those who were obese were more likely to have the two conditions: acanthosis nigricans (59% vs 44%; P=0.005) and insulin resistance (35% vs 19%; P=0.001). Compared with those without acanthosis nigricans, those with the condition had significantly higher mean values for systolic blood pressures (P<0.001), 2-hour post-oral glucose tolerance test glucose level (P=0.021), fasting insulin level (P<0.001), homeostasis model of assessment–insulin resistance (P<0.001), fasting triglyceride level (P<0.001), and alanine aminotransferase level (P=0.002), but a lower high-density lipoprotein cholesterol level (P<0.001). Those with acanthosis nigricans were also more likely to have insulin resistance (P<0.001), hypertension (P=0.021), fatty liver (P=0.001), and abnormal glucose homeostasis (P=0.003).
 
Conclusion: Obese Chinese children and adolescents with acanthosis nigricans had a higher chance of having insulin resistance and cardiometabolic co-morbidities. Acanthosis nigricans is an important clinical feature warranting early attention and evaluation to facilitate timely interventions and monitoring.
 
 
New knowledge added by this study
  • Hong Kong Chinese children with acanthosis nigricans were more likely to have insulin resistance, hypertension, fatty livers, and abnormal glucose homeostasis.
Implications for clinical practice or policy
  • In children, acanthosis nigricans is an important clinical sign warranting early attention and evaluation.
 
Introduction
Obesity was formally recognised as a global epidemic by the World Health Organization (WHO) in 1997.1 During the past decades, the prevalence of being overweight and obese has increased substantially. In Hong Kong, 17% of children were overweight/obese in 2005/6, which was a 5% increase since 1993, based on International Obesity Task Force cut-offs.2
 
Overweight/obese children and adolescents are more likely to have hyperinsulinaemia, hypertension, and dyslipidaemia.3 The clustering of cardiometabolic risk factors in these patients tends to track into adult life.3 However, the Diabetes Prevention Program demonstrated that lifestyle interventions could prevent or postpone the onset of type 2 diabetes mellitus (DM) by 58% in adults.4 Thus, identifying at-risk groups may allow early interventions and prevention of potential cardiometabolic complications.
 
Acanthosis nigricans (AN)—a hyperpigmented, thickened, and velvety dermatosis at the nape of the neck or axilla—is an easily identifiable physical sign.5 The American Diabetes Association includes it as an indicator of DM risk in overweight youths entering puberty.6 Yet, some authors have argued that it is not an independent predictor of insulin resistance (IR) if body mass index (BMI) is controlled for.7
 
Ethnic differences occur in obesity indices and their associated risk factors include IR.8 Local studies focusing on associations between AN with IR and other cardiometabolic co-morbidities in Chinese paediatric age-groups are sparse. In this regional centre study, we describe the demographic characteristics and IR in obese Chinese children with and without AN, with a focus on exploring the associations of AN with IR and other cardiometabolic co-morbidities.
 
Methods
A retrospective study was conducted by recruiting overweight/obese children and adolescents between 5 and 18 years of age who underwent obesity assessment between January 2006 and December 2010 in a regional hospital in Hong Kong. Patients were excluded if they had underlying metabolic diseases, chronic diseases, or other medical conditions resulting in obesity. Patients taking on medications that would alter metabolic profiles were also excluded.
 
Anthropometric data and AN status were recorded. Blood samples were collected. Ultrasound liver scans were performed on patients with elevated alanine aminotransferase (ALT) levels. Height was measured to the nearest 0.1 cm using the Harpenden stadiometer (Holtain; Crymych, UK) and body weight to the nearest 0.1 kg with light clothing using an electronic column scale (SECA-780; Seca Ltd, Hamburg, Germany). The BMI (kg/m2) percentiles of 90th and 97th centiles were used to define overweight and obesity, respectively.9 10 Local percentile standards were based on a local population survey conducted in 1993.11 The BMI z-score was calculated using this local age- and gender-specific reference. Blood pressure (BP) was measured using the standard oscillometric method (BP-8800C; Colin Electronics, Komaki, Japan) in the daytime with the children seated and rested. Average BP was obtained from two measurements. The BP z-score was calculated using the local BP reference.12 Participants were considered hypertensive if the mean systolic BP z-score and/or diastolic BP (DBP) z-score was/were greater than or equal to the 95th centiles for age and gender.
 
The diagnosis of AN was made by paediatricians; additional scoring for this entity was not undertaken as not all authors agreed that specific quantitative scales could improve the accuracy of IR prediction.13
 
Blood samples for plasma glucose, insulin, lipid profile, and liver enzymes following an overnight fasting were obtained and a standard oral glucose tolerance test (OGTT) was performed. The homeostasis model of assessment (HOMA)–IR value was used to assess IR using the following equation: fasting glucose (mmol/L) x fasting insulin (µU/mL)/22.5.14 Any HOMA value of ≥4 was considered to indicate IR. Glucose abnormalities were defined according to criteria from the WHO.15 Abnormal glucose homeostasis was referred to any combination of impaired fasting glucose, impaired glucose tolerance, or DM on the basis of fasting or 2-hour plasma glucose levels in the OGTT.16 17 Fatty liver was diagnosed by ultrasound scan affirmed by the operational definition of non-alcoholic fatty liver disease in the Asia-Pacific region.18
 
Statistical analyses
The statistical analyses were conducted using the Statistical Product and Service Solutions (version 17.0 for Windows 7). Taking P<0.05 as statistically significant, Student’s t test and Wilcoxon rank-sum test were used to compare results with a normal and skewed distribution, respectively. The Chi squared test or Fisher’s exact test as appropriate were used to analyse categorical variables. Multiple logistic regression analysis was then performed to identify independent factors associated with IR. To avoid multicollinearity, body weight and height were not used in the model, since both variables correlated highly with BMI. For the same reason, fasting insulin and glucose levels were not selected for the model as the HOMA-IR was derived from them. The model was simplified in a backward stepwise fashion by removing variables with P values of >0.1. Goodness-of-fit of the regression model was tested with the Hosmer-Lemeshow test.
 
Results
A total of 543 overweight/obese Chinese patients were included in this study. They had a mean ± standard deviation age of 12 ± 3 years and 64% (n=346) of them were boys. The majority (77%, n=419) were obese with a BMI of >97%. In all, AN was present in 54% (n=295) of the subjects and 29% (n=156) of them had IR. Relevant data are summarised in Table 1.
 

Table 1. Basic characteristics of 543 children
 
Table 2 illustrates that adolescents (aged 12-18 years), compared with younger children (aged 5-11 years), were more likely to have AN (63% vs 47%; P<0.001) and IR (37% vs 25%; P=0.005). Obese children, compared with overweight children, were also more likely to have AN (59% vs 44%; P=0.005) and IR (35% vs 19%; P=0.001).
 

Table 2. Comparison of acanthosis nigricans and insulin resistance in subgroups
 
Table 3 shows baseline characteristics and biochemical parameters in children with and without AN. Apart from being older, the group with AN had higher mean 2-hour post-OGTT glucose (P=0.021), fasting insulin (P<0.001), triglyceride (P<0.001), and ALT (P=0.002) levels, but lower mean levels of high-density lipoprotein (HDL) cholesterol (P<0.001). Their BMI (P<0.001), BMI z-score (P<0.001), systolic blood pressure (SBP) [P<0.001], and HOMA-IR values (P<0.001) were also higher. Notably, the higher SBP, when converted to SBP z-score (taking into account age and gender), was no longer significant. Both DBP and DBP z-scores showed no differences between the two groups. The presence of IR and other cardiometabolic co-morbidities in subjects with and without AN are also shown in Table 3. The frequencies of IR, hypertension, fatty liver, and abnormal glucose homeostasis were all significantly higher in subjects with AN.
 

Table 3. Comparisons between the groups with or without acanthosis nigricans
 
Further analysis of risk factors for IR using the multiple logistic regression model showed that the presence of AN (odds ratio [OR]=2.36; 95% confidence interval [CI], 1.46-3.80; P<0.001), older age (1.17; 1.07-1.28; P=0.001), higher triglyceride level (1.91; 1.33-2.74; P<0.001), and higher BMI z-score (6.95; 3.40-14.16; P<0.001) were significant independent variables predicting IR (Table 4). However, though HDL and 2-hour post-OGTT glucose level were borderline significant predictors for IR, their effect sizes were small. The Hosmer-Lemeshow test of goodness-of-fit was 0.315, indicating a good logistic regression model fit.
 

Table 4. Associations between clinical and laboratory parameters and insulin resistance according to the multivariate analysis
 
Discussion
Obesity is a public health problem that has become epidemic worldwide. In the primary care setting, identifying children with AN may allow early implementation of interventions to prevent the development of DM and other cardiometabolic co-morbidities in overweight/obese children.16 Searching for AN over the neck is easy, non-intrusive. and acceptable to the children.19 Presence of AN can also be used as a grounds to initiate and reinforce discussions about lifestyle modification.5 19 20
 
An observed AN frequency of 54% in our subjects was consistent with data reported in the literature.21 22 Our adolescents were more likely to have AN than younger children, in line with hyperinsulinaemia being more severe among older individuals.22 In our study, development of AN showed no gender preference, as in a study of 1412 unselected children by Stuart et al.23 In our cohort and that in Nsiah-Kumi et al’s study,13 obese children were more likely to have AN than overweight ones.
 
Whilst IR is a hallmark of obesity, it is also associated with other metabolic derangements and clinical or subclinical cardiovascular diseases.24 We used the HOMA-IR value—a simple, validated, and practical marker of IR in the paediatric population—to give a more physiological estimate of glucose homeostasis,25 that was also shown to correlate well with the hyperinsulinaemic-euglycaemic glucose clamp technique, a gold standard for quantifying insulin sensitivity.24 In a local community-based cross-sectional study, it was shown that the mean HOMA-IR value was lower among Hong Kong Chinese adolescents than subjects in the United States.8 Currently, there is no worldwide consensus on defining IR among children. Some studies have chosen an HOMA-IR value as low as 2.7 while others have shown that a value of 4 can be present in pubertal children (because of the transient physiological IR during puberty).13 Although we do not have data about pubertal stage in our study subjects, an HOMA-IR of ≥4 would be a conservative but reasonable definition of IR, in parallel with the threshold used in a multicentre trial in the United States (Studies to Treat or Prevent Pediatric Type 2 Diabetes—STOPP-T2DM).26
 
In our study, 29% of our cohort had IR using the cut-off HOMA-IR of ≥4, and the mean value was higher among those with AN present (3.6 vs 2.6; P<0.001). Notably, IR was more common among adolescents than young children (37% vs 25%; P=0.005) as well as among obese than overweight subjects (35% vs 19%; P=0.001). Goran et al27 suggested that long-standing obesity and the physiological IR during puberty accounted for adolescents having more AN and IR. They found that pubertal transition from Tanner I to Tanner III was associated with a 32% reduction in insulin sensitivity across different genders and ethnicities, and proved that body fat was the predominant factor influencing IR whereas total and visceral fat both contributed independently to lower insulin sensitivity.27 Notably, 25% of our young (5-11 years old) overweight/obese subjects already had IR, suggesting that the onset of metabolic derangement might have started long before adolescence and indicates that screening should begin early during childhood.
 
In our cohort, IR and other cardiometabolic co-morbidities were more prevalent among those with AN. The relationship of AN with hypertension may not be as strong as that with fatty liver and abnormal glucose homeostasis. This might be consistent with hypertension being more closely related to obesity than to AN.28 Nevertheless, studies assessing the relationship of BP and insulin levels are conflicting.29 Some authors postulate that the underlying pathophysiology is a common genetic predisposition to both IR and hypertension, whilst also involving other mechanisms.30
 
Dyslipidaemia is believed to play a central role in the development of heart diseases. High level of triglyceride and low level of HDL cholesterol are commonly used criteria to define metabolic syndrome both in children and adults.31 High triglyceride levels and the IR index (HOMA-IR) were strong, independent predictors of increased carotid intima-media thickness, which was a non-invasive measure of subclinical atherosclerosis in paediatric research.32 Nevertheless, low HDL cholesterol level carried an even greater relative risk than high triglyceride levels.33 Compared with those without AN, subjects with the condition had a higher mean triglyceride level (P<0.001) but lower HDL level (P<0.001), and hence their future cardiovascular health seems to be of great concern.
 
Fatty liver, or non-alcoholic fatty liver disease (NAFLD), can be classified into isolated fatty liver in which there is only accumulation of fat, and non-alcoholic steatohepatitis (NASH) in which there is fat accumulation and damage to liver cells. Presence of the latter is associated with raised liver enzymes and more abnormal ultrasound scans. Our subjects with AN had higher levels of ALT (P=0.002) and a higher proportion with fatty livers. In contrast, Uwaifo et al34 reported that AN was not common among a small cohort of 28 subjects with biopsy-proven NASH, despite their high prevalence of IR. These authors therefore questioned the use of AN as an index of IR in patients with NASH. However, in our study liver ultrasounds were only performed in children with raised ALT levels. According to Sartorio et al,35 the ALT level alone was insufficient as a marker of NAFLD and the sensitivity of using its level to predict NAFLD was as low as 41% (depending on the cut-off used). Several prediction scores have been developed for non-invasive liver steatosis screening, but they have insufficient diagnostic accuracy among obese children.36
 
For DM, incidence, prevalence, and disease progression are believed to vary in different ethnic groups. The overall frequency of abnormal glucose homeostasis of 10% (8% impaired glucose tolerance and 2% with DM; data not shown) was lower than in a recent study by Brickman et al16 who reported a 29% frequency of abnormal glucose homeostasis among a group of 8-to-14 years old, mainly of Hispanic and African American children with AN. Another study from the United Kingdom found a higher frequency of type 2 DM among African-Caribbean and South Asian groups, while the Chinese and white Caucasians had the lowest frequencies.37 The reasons for such inter-ethnic differences are still unclear but do not seem to be solely genetic, as inter-generational social factors may also modify the evolution and biology of the disease.37 Our results, together with the recently reported sharp rise in the incidence of type 2 DM in Hong Kong children aged under 19 years after 2004,38 should alert our health care professionals as to the importance of early detection of potential predictors of abnormal glucose metabolism such as AN.
 
Recently, the role of IR in cardiometabolic derangements has attracted more attention. Nevertheless, there is no prediction model for IR in our local children and adolescents. Using multivariate analysis, our study demonstrates that age, AN status, triglyceride level, and BMI z-score are significant independent variables associated with IR. Hopefully, a simple and practical prediction model of IR with acceptable sensitivity and specificity can be derived by combining these clinical findings, anthropometric measurements, and biochemical markers.
 
Limitations
Important limitations of this study included its retrospective design, being single-centred, and thus not being suitable for calculating population-based rates. In addition, the stage of puberty (not documented) may also influence IR. Moreover, several relevant risk factors (family history of metabolic derangement, maternal gestational DM, duration of obesity, socio-economic status) were not included in the analysis. As in other retrospective studies, it was not possible to retrieve every single item of data. Notably, AN status was unavailable in 11 (2%) patients while HOMA-IR information was absent in 46 (8%) of the subjects, as fasting insulin levels were not checked and might have contributed to selection bias. Our study was clinic-based and not population-based, and so an overestimate of morbidity was a possibility. Besides, establishing a relationship between cause and effect was not possible due to the cross-sectional nature of the study. Growth data collected in 1993 (HK1993) are still widely used locally and seem appropriate in Hong Kong.9 We adopted the operational BMI cut-offs for daily use locally. However, the ideal cut-offs for being overweight and having obesity remain controversial, and various definitions and operational values exist.39 These problems may also limit direct comparisons between different studies using different growth references and cut-offs.39
 
Conclusion
Local obese Chinese children with AN are at higher risk of IR and cardiometabolic co-morbidities. Primary care physicians should be vigilant for this clinical sign. If present, early attention is necessary to achieve early intervention. Further studies may be necessary to evaluate the longitudinal risk relationship between AN and cardiometabolic outcomes.
 
References
1. Caballero B. The global epidemic of obesity: an overview. Epidemiol Rev 2007;29:1-5. CrossRef
2. So HK, Nelson EA, Li AM, et al. Secular changes in height, weight and body mass index in Hong Kong Children. BMC Public Health 2008;8:320. CrossRef
3. Bao W, Srinivasan SR, Wattigney WA, Berenson GS. Persistence of multiple cardiovascular risk clustering related to syndrome X from childhood to young adulthood: the Bogalusa Heart Study. Arch Intern Med 1994;154:1842-7. CrossRef
4. Knowler WC, Barrett-Connor E, Fowler SE, et al. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med 2002;346:393-403. CrossRef
5. Kong AS, Williams RL, Smith M, et al. Acanthosis nigricans and diabetes risk factors: prevalence in young persons seen in southwestern US primary care practices. Ann Fam Med 2007;5:202-8. CrossRef
6. American Diabetes Association. Type 2 diabetes in children and adolescents. Diabetes Care 2000;23:381-9. CrossRef
7. Ice CL, Murphy E, Minor VE, Neal WA. Metabolic syndrome in fifth grade children with acanthosis nigricans: results from the CARDIAC project. World J Pediatr 2009;5:23-30. CrossRef
8. Kong AP, Choi KC, Ko GT, et al. Associations of overweight with insulin resistance, beta-cell function and inflammatory markers in Chinese adolescents. Pediatr Diabetes 2008;9:488-95. CrossRef
9. So HK, Nelson EA, Sung RY, Ng PC. Implications of using World Health Organization growth reference (2007) for identifying growth problems in Hong Kong children aged 6 to 18 years. Hong Kong Med J 2011;17:174-9.
10. Ng DK, Lam YY, Kwok KL, Chow PY. Obstructive sleep apnoea syndrome and obesity in children. Hong Kong Med J 2004;10:44-8.
11. Leung SS, Cole TJ, Tse LY, Lau JT. Body mass index reference curves for Chinese children. Ann Hum Biol 1998;25:169-74. CrossRef
12. Sung RY, Choi KC, So HK, et al. Oscillometrically measured blood pressure in Hong Kong Chinese children and associations with anthropometric parameters. J Hypertens 2008;26:678-84. CrossRef
13. Nsiah-Kumi PA, Beals J, Lasley S, et al. Body mass index percentile more sensitive than acanthosis nigricans for screening Native American children for diabetes risk. J Natl Med Assoc 2010;102:944-9.
14. Matthews D, Hosker J, Rudenski A, Naylor B, Treacher D, Turner R. Homeostasis model assessment: insulin resistance and β-cell function from fasting plasma glucose and insulin concentrations in man. Diabetologia 1985;28:412-9. CrossRef
15. Definition, diagnosis and classification of diabetes and its complications: report of a WHO consultation, part 1: diagnosis and classification of diabetes mellitus. Geneva, Switzerland: World Health Organization; 1999.
16. Brickman WJ, Huang J, Silverman BL, Metzger BE. Acanthosis nigricans identifies youth at high risk for metabolic abnormalities. J Pediatr 2010;156:87-92. CrossRef
17. Atabek ME, Pirgon O, Kurtoglu S. Assessment of abnormal glucose homeostasis and insulin resistance in Turkish obese children and adolescents. Diabetes Obes Metab 2007;9:304-10. CrossRef
18. Chitturi S, Farrell GC, Hashimoto E, et al. Non-alcoholic fatty liver disease in the Asia-Pacific region: definitions and overview of proposed guidelines. J Gastroenterol Hepatol 2007;22:778-87. CrossRef
19. Smith WG, Gowanlock W, Babcock K, et al. Prevalence of acanthosis nigricans in First Nations children in Central Ontario, Canada. Can J Diabetes 2004;28:410-4.
20. Kong AS, Williams RL, Rhyne R, et al. Acanthosis nigricans: high prevalence and association with diabetes in a practice-based research network consortium—a PRImary care Multi-Ethnic network (PRIME Net) study. J Am Board Fam Med 2010;23:476-85. CrossRef
21. Shalitin S, Abrahami M, Lilos P, Phillip M. Insulin resistance and impaired glucose tolerance in obese children and adolescents referred to a tertiary-care center in Israel. Int J Obes (Lond) 2005;29:571-8. CrossRef
22. Kluczynik CE, Mariz LS, Souza LC, Solano GB, Albuquerque FC, Medeiros CC. Acanthosis nigricans and insulin resistance in overweight children and adolescents. An Bras Dermatol 2012;87:531-7. CrossRef
23. Stuart CA, Pate CJ, Peters EJ. Prevalence of acanthosis nigricans in an unselected population. Am J Med 1989;87:269-72. CrossRef
24. Singh B, Saxena A. Surrogate markers of insulin resistance: a review. World J Diabetes 2010;1:36-47. CrossRef
25. Keskin M, Kurtoglu S, Kendirci M, Atabek ME, Yazici C. Homeostasis model assessment is more reliable than the fasting glucose/insulin ratio and quantitative insulin sensitivity check index for assessing insulin resistance among obese children and adolescents. Pediatrics 2005;115:e500-3. CrossRef
26. Studies to Treat or Prevent Pediatric Type 2 Diabetes Prevention Study Group. Prevalence of the metabolic syndrome among a racially/ethnically diverse group of U.S. eighth-grade adolescents and associations with fasting insulin and homeostasis model assessment of insulin resistance levels. Diabetes Care 2008;31:2020-5. CrossRef
27. Goran MI, Ball GD, Cruz ML. Obesity and risk of type 2 diabetes and cardiovascular disease in children and adolescents. J Clin Endocrinol Metab 2003;88:1417-27. CrossRef
28. Sorof JM, Lai D, Turner J, Poffenbarger T, Portman RJ. Overweight, ethnicity, and the prevalence of hypertension in school-aged children. Pediatrics 2004;113:475-82. CrossRef
29. Jessup A, Harrell JS. The metabolic syndrome: look for it in children and adolescents, too! Clin Diabetes 2005;23:26-32. CrossRef
30. El-Atat FA, Stas SN, McFarlane SI, Sowers JR. The relationship between hyperinsulinemia, hypertension and progressive renal disease. J Am Soc Nephrol 2004;15:2816-27. CrossRef
31. Reinehr T, de Sousa G, Toschke AM, Andler W. Comparison of metabolic syndrome prevalence using eight different definitions: a critical approach. Arch Dis Child 2007;92:1067-72. CrossRef
32. Fang J, Zhang JP, Luo CX, Yu XM, Lv LQ. Carotid intima-media thickness in childhood and adolescent obesity relations to abdominal obesity, high triglyceride level and insulin resistance. Int J Med Sci 2010;7:278-83. CrossRef
33. Bray GA. Medical consequences of obesity. J Clin Endocrinol Metab 2004;89:2583-9. CrossRef
34. Uwaifo GI, Tjahjana M, Freedman RJ, Lutchman G, Promrat K. Acanthosis nigricans in patients with nonalcoholic steatohepatitis: an uncommon finding. Endocr Pract 2006;12:371-9. CrossRef
35. Sartorio A, Del Col A, Agosti F, et al. Predictors of non-alcoholic fatty liver disease in obese children. Eur J Clin Nutr 2007;61:877-83. CrossRef
36. Koot BG, van der Baan-Slootweg OH, Bohte AE, et al. Accuracy of prediction scores and novel biomarkers for predicting nonalcoholic fatty liver disease in obese children. Obesity (Silver Spring) 2013;21:583-90. CrossRef
37. Oldroyd J, Banerjee M, Heald A, Cruickshank K. Diabetes and ethnic minorities. Postgrad Med J 2005;81:486-90. CrossRef
38. Huen KF, Low LC, Cheung PT, et al. An update on the epidemiology of childhood diabetes in Hong Kong. Hong Kong J Paediatr 2009;14:252-9.
39. Rolland-Cachera MF. Childhood obesity: current definitions and recommendations for their use. Int J Pediatr Obes 2011;6:325-31. CrossRef

Severe acute pyelonephritis: a review of clinical outcome and risk factors for mortality

Hong Kong Med J 2014 Aug;20(4):285–9 | Epub 14 March 2014
DOI: 10.12809/hkmj134061
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE     CME 
Severe acute pyelonephritis: a review of clinical outcome and risk factors for mortality
Vera Y Chung, FHKAM (Surgery), FRCS (Edin); CK Tai, FHKAM (Surgery), FRCS (Edin); CW Fan, FHKAM (Surgery), FRCS (Edin); CN Tang, FHKAM (Surgery), FRCS (Edin)
Division of Urology, Department of Surgery, Pamela Youde Nethersole Eastern Hospital, Chai Wan, Hong Kong
 
Corresponding author: Dr VY Chung (chungyeungvera@gmail.com)
 Full paper in PDF
Abstract
Objective: To review demographics of patients with acute pyelonephritis, their outcomes of severe upper urinary tract infection, and to identify risk factors for long hospital stay and mortality.
 
Design: Case series.
 
Setting: A regional hospital in Hong Kong.
 
Patients: Patients admitted between June 2007 and June 2012 for acute pyelonephritis were identified. Those with the most severe outcomes were analysed of their mortality, need for care in the intensive care unit, or necessitation of urological intervention.
 
Results: Overall, 68 patients fulfilled our criteria for severe acute pyelonephritis. The female-to-male ratio was 7:3. Their mean age was 58 years. Overall, 57% of the patients had impaired renal function and 37% were diabetic; 47% developed shock after admission and 56% required further intensive care unit care; 75% of the patients demonstrated radiological evidence of urinary tract obstruction and required subsequent drainage procedures. Five patients died due to severe acute pyelonephritis. The prevalence of bacteraemia and bacteriuria was 57% and 74%, respectively. Escherichia coli accounted for the majority of causative organisms. Four risk factors—bacteraemia, shock, need for intensive care, and suppurative pyelonephritis—were associated with hospital stay of longer than 14 days. Old age (≥65 years), male sex, deranged renal function, and presence of disseminated intravascular coagulation were associated with mortality.
 
Conclusion: There was high prevalence of bacteraemia and septic shock in patients with severe acute pyelonephritis. The factors of old age (≥65 years), male sex, deranged renal function, and presence of disseminated intravascular coagulation were associated with mortality. With the support of intensive care, early recognition of urinary tract obstruction and timely drainage, patients with severe acute pyelonephritis generally carry a good prognosis.
 
 
New knowledge added by this study
  • Contrary to the usual belief, the complexity of renal infections and septic shock were predictors for long hospital stay but not mortality.
  • Escherichia coli still accounts for the majority of causative organisms in hospitalised patients with severe acute pyelonephritis.
Implications for clinical practice or policy
  • Early recognition of urinary tract obstruction and timely drainage are important in the treatment of severe acute pyelonephritis.
  • Physicians could prevent potential mortalities by identifying those with risk factors and providing early intervention and intensive care.
 
Introduction
Acute pyelonephritis (AP) represents the most severe form of urinary tract infection (UTI) and is associated with significant morbidity and even mortality. Approximately 250 000 cases of AP occur each year in the US, with the incidence being higher in women than men.1 The aetiological agent is Escherichia coli in around 80% of the cases.2 Acute pyelonephritis has a quoted mortality of 10% to 20%.3 Several studies have identified a number of risk factors for prediction of poor outcome, including urinary tract abnormality, general debility, and properties (ie virulence and resistance profile) of microorganisms.4 5
 
The aim of this study was to review patient demographics and outcomes of severe AP in a regional hospital, and to identify possible prognostic factors for long hospital stay and fatal events.
 
Methods
Study design and data collection
We conducted a retrospective medical record review. All patients admitted for AP between June 2007 and June 2012 to Pamela Youde Nethersole Eastern Hospital, Hong Kong were identified. Only patients with the most severe outcomes were analysed consecutively: (1) mortality, (2) need for care in the intensive care unit (ICU), or (3) necessitation of urological intervention. Patients suffering from postoperative pyelonephritis were excluded.
 
The following data were collected: patient demographics, presence of urinary tract obstruction, presence of septic shock, need for intensive care, modalities of urological intervention, bacteriologies, length of stay, and mortality.
 
Statistical analysis
Data analysis was performed by the Statistical Package for the Social Sciences (Windows version 20; SPSS Inc, Chicago [IL], US). A P value of less than 0.05 was regarded as statistically significant. Chi squared test and logistic regression analysis were performed. The independent variables were patients’ demographic and clinical data; the dependent variables were mortality and long hospital stay (>14 days).
 
Results
Patient characteristics
A total of 432 patients were admitted for AP from June 2007 to June 2012. Of these, 68 patients fulfilled our inclusion criteria for severe AP. Baseline patient demographics, clinical characteristics, and imaging findings are illustrated in Table 1.6 Overall, 75.0% of the patients (n=51) demonstrated radiological evidence of urinary tract obstruction, secondary to stone (51.0%), ureteral stricture (5.8%), or extrinsic compression (7.2%). Six patients had suppurative renal infections, namely, renal abscess and emphysematous pyelonephritis.
 

Table 1. Patient demographics and clinical data
 
Microbiology
The yields of blood culture were positive in 57.4% of the patients, with E coli being the commonest causative organism (38.2%) followed by Klebsiella pneumoniae, Proteus mirabilis, and Acinetobacter species. Only three patients had bacteraemia caused by extended-spectrum β-lactamase–producing E coli (Table 2).
 

Table 2. Results of blood and urine culture
 
The prevalence of bacteriuria was 73.5%, and E coli accounted for the majority of cases with bacteriuria, followed by K pneumoniae and Pseudomonas aeruginosa (Table 2).
 
Urological procedure
In addition to antibiotic administration, 75% (n=51) of the patients required urological interventions, including percutaneous nephrostomy (n=41), insertion of ureteric stent (n=5), percutaneous drainage (n=1), and nephrectomy (n=5).
 
Mortality due to pyelonephritis
The overall mortality was 7.4% (n=5). Table 3 summarises the characteristics of patients who died due to pyelonephritis within the same admission.
 

Table 3. Details of patients who died due to acute pyelonephritis
 
Prognostic factors for long hospital stay and mortality
Risk factors for long hospital stay (>14 days; 32.4%) and mortality (7.4%) were analysed (Tables 4 and 5).
 

Table 4. Prognostic factors for long hospital stay (>14 days)
 
 

Table 5. Prognostic factors for mortality
 
Presence of bacteraemia (P=0.022), suppurative pyelonephritis (P=0.005), shock (P=0.016), and need for ICU care (P=0.003) were significant risk factors for long hospital stay on univariate analysis. On multivariate analysis, the odds ratios (ORs) were 3.71 for bacteraemia (P=0.026), 13.23 for suppurative pyelonephritis (P=0.022), 3.65 for shock (P=0.018), and 5.85 for ICU care (P=0.005).
 
On univariate analysis, age of ≥65 years, male sex, deranged renal function, and disseminated intravascular coagulation (DIC) were predictors for death. However, only male sex (OR=11.75; P=0.033) and DIC (OR=10.31; P=0.018) were shown to be independent risk factors in multivariate regression analysis.
 
Discussion
Severe AP is an important disease entity that frequently requires hospitalisation. Early recognition of patients who are at risk of prolonged hospital stay or even fatal events is important to improve treatment results. Previous studies4 5 have shown a number of risk factors including immunosuppression, old age, and diabetes as risk factors for treatment failure. We were interested in finding whether these risk factors also applied to the local Hong Kong population.
 
An epidemiological study in the US found that women are approximately 5 times more likely than men to be hospitalised for AP; however, women have a lower mortality rate than men.7 In our study of hospitalised patients, females accounted for the majority (70.6%) of AP cases. However, all but one mortality from pyelonephritis occurred in the male patients.
 
In one study on AP in adults, E coli was the aetiological agent in 80% of the cases, but E coli infections were less common in elderly patients (60%). Furthermore, infections due to P mirabilis, K pneumoniae, Serratia marcescens, and P aeruginosa were very common due to the increased use of catheters.2 Our study showed a similar microbial spectrum. However, in AP, it is not always possible to routinely document clinical UTI. This could be attributed to previous antibiotic treatment, low bacterial growth, or presence of atypical pathogens.8 In the present analysis, it was possible that a certain proportion of patients had received antibiotic treatment before admission to the hospital. Despite this, the prevalence of bacteraemia and bacteriuria was relatively high (57.4% and 73.5%, respectively). Escherichia coli accounted for the majority of causative organisms.
 
An obstructed and infected kidney is a urological emergency that may progress to septic shock. Since acute obstructive uropathy raises the renal pelvic pressure and, theoretically, decreases the uptake of drugs by the kidney, emergency drainage is warranted. A urological intervention significantly increases the chances of good initial outcome.6 9 In this study, all patients who showed radiological evidence of urinary tract obstruction were treated with emergency drainage.
 
It has been suggested that bacteriuria and UTI occur more commonly in subjects with diabetes than in the general population, and the risk of upper tract involvement is also increased in these people.10 Diabetes seems to be associated with an increased risk of severe UTI and unusual manifestations.11 12 The prevalence of diabetes in the present study was also high (36.8%). In contrast with the results of several studies, it was not shown to be a risk factor for prolonged hospitalisation.4 5 The initial choice of empirical antimicrobial therapy was not different for diabetic patients, but we were more vigilant for complications of UTI, such as emphysematous pyelonephritis and abscess formation, in this group of patients.
 
Recent reports4 13 have shown other risk factors such as long-term catheterization and age of >65 years to be predictive of prolonged hospitalisation. Our study revealed that four risk factors—including bacteraemia, shock, need for intensive care, and suppurative pyelonephritis—were associated with long hospital stay. These four risk factors were closely related with and denoted the most severe degree of pyelonephritis, thus resulting in longer hospitalisation.
 
The mortality rate for patients with pyelonephritis has been reported to be 1.2% to 33%.14 15 In our study, which included more severe group of AP patients (ie those who required intensive care or urological interventions), the overall mortality rate was 7.4%. According to a previous study,4 septic shock, bedridden status, age of >65 years, recent use of antibiotics, and immunosuppression were independent predictors of death. Another research found that baseline health status of patients and complexity of suppuration were the most important predictors of clinical outcomes for suppurative renal infections.6 In our analysis, patients who died due to AP were predominantly older than 65 years, presented with septic shock, and required drainage for urinary tract obstruction. Among the risk factors studied, age of ≥65 years, male sex, deranged renal function, and DIC were associated with mortality in univariate analysis. Additional multivariate correlates were male sex and presence of DIC.
 
The limitation of the study was that the study population consisted of a heterogeneous group of patients and might not be representative of the majority of uncomplicated AP cases. Presence of resistant pathogens may contribute to treatment failure, but we did not estimate this factor in our analysis. Nevertheless, the outcomes of severe AP also bear clinical implications for physicians who mainly treat critically ill, hospitalised patients.
 
Conclusion
There was high prevalence of bacteraemia and septic shock in patients with severe AP, with E coli being the predominant causative organism. Male sex and presence of DIC were associated with mortality. Early recognition of risk factors can potentially help prevent death from severe AP.
 
References
1. Ramakrishanan K, Scheid DC. Diagnosis and management of acute pyelonephritis in adults. Am Fam Physician 2005;71:933-42.
2. Stamm WE, Hooton TM. Management of urinary tract infections in adults. N Engl J Med 1993;329:1328-34. CrossRef
3. Roberts FJ, Geere IW, Coldman A. A three-year study of positive blood cultures, with emphasis on prognosis. Rev infect Dis 1991;13:34-6. CrossRef
4. Efstathiou SP, Pefanis AV, Tsioulos DI, et al. Acute pyelonephritis in adults: prediction of mortality and failure of treatment. Arch Int Med 2003;163:1206-12. CrossRef
5. Pertel PE, Haverstock D. Risk factors for a poor outcome after therapy for acute pyelonephritis. BJU Int 2006;98:141-7. CrossRef
6. Stojadinović MM, Mićić SR, Milovanović DR, Janković SM. Risk factors for treatment failure in renal suppurative infections. Int Urol Nephrol 2009;41:319-25. CrossRef
7. Foxman B, Klemstine KL, Brown PD. Acute pyelonephritis in US hospitals in 1997: hospitalization and in-hospital mortality. Ann Epidemiol 2003;13:144-50. CrossRef
8. Rollino C, Beltrame G, Ferro M, Quattrocchio G, Sandrone M, Quarello F. Acute pyelonephritis in adults: a case series of 223 patients. Nephrol Dial Transplant 2012;27:3488-93. CrossRef
9. Yamamoto Y, Fujita K, Nakazawa S, et al. Clinical characteristics and risk factors for septic shock in patients receiving emergency drainage for acute pyelonephritis with upper urinary tract calculi. BMC Urology 2012;12:4. CrossRef
10. Stapleton A. Urinary tract infections in patients with diabetes. Am J Med 2008;113:80-4. CrossRef
11. Patterson JE, Andriole VT. Bacterial urinary tract infections in diabetes. Infect Dis Clin North Am 1995;9:25-51.
12. Lye WC, Chan RK, Lee EJ, Kumarasinghe G. Urinary tract infections in patients with diabetes mellitus. J Infect 1992;24:169-74. CrossRef
13. Roberts JA. Management of pyelonephritis and upper urinary tract infections. Urol Clin North Am 1999;26:753-63.  CrossRef
14. Lee JH, Lee YM, Cho JH. Risk factors of septic shock in bacteremic acute pyelonephritis patients admitted to an ER. J Infect Chemother 2012;18:130-3. CrossRef
15. Yoshimura K, Utsunomiya N, Ichioka K, Ueda N, Matsui Y, Terai A. Emergency drainage from urosepsis associated with upper urinary tract calculi. J Urol 2005;173:458-62. CrossRef

Double free flaps for reconstruction of complex/composite defects in head and neck surgery

Hong Kong Med J 2014 Aug;20(4):279–84 | Epub 28 Mar 2014
DOI: 10.12809/hkmj134113
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Double free flaps for reconstruction of complex/composite defects in head and neck surgery
Kevin WL Mo, MRCS1; Alexander Vlantis, FCS(SA)ORL2; Eddy WY Wong, FRCSEd(ORL), FHKCORL2; TW Chiu, FHKAM (Surgery)1
1 Division of Plastic, Reconstructive and Aesthetic Surgery, Department of Surgery, Prince of Wales Hospital, Shatin, Hong Kong
2 Department of Otorhinolaryngology, Head and Neck Surgery, Prince of Wales Hospital, Shatin, Hong Kong
 
Corresponding author: Dr TW Chiu (torchiu@surgery.cuhk.edu.hk)
 Full paper in PDF
Abstract
Objective: To demonstrate the feasibility of double free flap surgery in head and neck reconstruction.
 
Design: Descriptive case series.
 
Setting: A university-affiliated hospital in Hong Kong.
 
Patients: Twelve patients with head and neck cancer (encountered over a 2.5-year period) who had reconstructive surgery with planned simultaneous double free flaps.
 
Results: The mean total operating time was 660 minutes and there were no flap failures. Postoperative stays ranged from 11 to 82 days; nine patients were discharged within 3 weeks and seven were able to maintain their weight with oral feeding. The survival rate up to 1 year was 64%.
 
Conclusion: The use of double free flaps is an option worth considering for complex head and neck defects in carefully selected patients.
 
 
Click here to watch a video of double free-flap reconstruction
 
New knowledge added by this study
  • Double free flaps can be used with good flap success rates, operating times, and patient outcomes.
Implications for clinical practice or policy
  • Concerns over the use of double free flaps in head and neck reconstruction should not deter experienced microsurgeons from this procedure whenever they are deemed to offer significant advantages, in terms of reconstructions involving large bulks, multiple surfaces, or multiple tissue types.
 
Introduction
The use of microvascular free flaps for the reconstruction of defects following the resection of head and neck cancer is a complex but routine procedure. However, single flaps may not be sufficient for some defects that are either too large or warrant composite tissues. In particular, resection of advanced tumours of the oral cavity results in complex oromandibular defects that often involve bone, oral lining, external skin, and soft tissue. The free fibular osteocutaneous (FO) flap is well established as a workhorse flap for mandible reconstruction,1 which provides 25 to 30 cm of straight bone of good quality that can be contoured, as well as a skin paddle for soft tissue coverage when needed. The pedicle has an acceptable length and its vessels have a good diameter. It is therefore our preferred option for restoring mandibular defects and for lining the oral cavity.
 
However, the size of the skin paddle is limited1 and may not be supplied by the same vessel as the bone.2 Thus, with larger composite defects, a single fibula flap cannot provide sufficient soft tissue coverage and a second skin flap may be necessary. Some surgeons nevertheless elect to avoid a second free flap by choosing either a pedicled flap or alloplastic material. We therefore set out to demonstrate the feasibility of resorting to double free flap surgery in head and neck reconstruction.
 
Our choice for additional soft tissue is the anterolateral thigh (ALT) flap that provides up to 630 cm2 of skin.3 On occasions when the vascularity of the fibula flap skin paddle is deemed borderline, the ALT can be harvested with multiple skin islands so as to cover both the inner lining and the external skin. Harvest of the FO and ALT flaps can proceed at the same time as tumour excision, without the need for patient re-positioning, which is an important logistical advantage. Like most surgeons, whenever possible we prefer using separate anastomoses for double flaps rather than sequential linking or ‘flow through’,4 5 6 as some studies5 6 suggest that the latter has more complications (possibly due to increased thrombogenicity or a ‘steal’ phenomena).
 
Methods
We conducted a retrospective case review of patients in our institution with head and neck cancer who had reconstruction with planned simultaneous double free flaps over a 2.5-year period (from November 2010 to August 2013). For all cases we deployed two surgical teams; reconstructions were performed (one surgeon) at the same time as tumour excision (other surgeons). Preoperatively, handheld Doppler probes were used to locate the skin perforators for both flaps. The peroneal artery was sacrificed in the harvest of fibula flaps and adequacy of the remaining vessels was screened by palpation of the dorsalis pedis and posterior tibial pulses. An angiogram was used in only one patient with a history of peripheral vascular disease.
 
The FO flap was harvested first using a lateral approach; a sterile tourniquet was placed on the upper thigh but not inflated. A skin island was harvested in nine out of 10 fibula flaps. In one patient, the skin island was not perfused by the peroneal artery and thus not harvested. In another, the vascularity of the skin island was deemed suboptimal and therefore not used. The fibula flap was kept in situ after isolation of its vascular pedicle while the ALT was harvested. Intramuscular perforators to the thigh skin island were skeletonised in all cases so as to completely visualise the vessels. Once the surgical margins were deemed clear by frozen sections, the final dimensions of the ALT flaps were determined when the final defect was defined.
 
Whenever possible, intermaxillary fixation was used to hold the mandible and maxilla in an optimal position, and ‘by eye’ the fibula was osteotomised to fit (average 1-2 osteotomies). Two sets of mini-plates were used per osteotomy site so as to maximise rotational stability. The use of 2.5 x or 3.5 x loupes by the reconstructive surgeon allowed micro-anastomoses of the vessels, whilst insetting of the flap was completed.
 
Illustrative case
A 58-year-old man was referred to our centre with a second recurrence of a squamous cell carcinoma of his tongue. Three years earlier, he had had a partial right glossectomy with a selective neck dissection for a pT2N0 lesion. One year later he underwent a complete neck dissection for a right nodal recurrence, and another year later he had had a reconstruction with a pectoralis major myocutaneous flap (PMMF) after total glossectomy for local tumour recurrence. After the tumour was resected, he had a bony defect from one angle of the mandible to the other, and a soft tissue defect that involved the entire inferior oral cavity down to the chin and anterior neck skin, which left a 3-cm rim of lower lip (Fig 1).
 

Figure 1. The large post-extirpative defect; the lower lip remnant has been retracted with a gauze sling
 
We used a fibula flap with its overlying skin island along with a large ALT flap (Fig 2). After anastomosis of the two sets of vessels, bleeding from the edge of the fibula flap skin island appeared rather sluggish. So the ALT was used for both intraoral lining and external skin cover. A strip of the ALT flap was de-epithelialised for suturing to the lower lip remnant (Fig 3). There were no major complications and the patient was discharged on the 14th postoperative day. There was a good contour at follow-up (Fig 4); the patient used a percutaneous endoscopic gastrostomy (PEG) for feeding preoperatively but regrettably could not resume oral feeding after this surgery and therefore remained reliant on the PEG.
 
 

Figure 2. The bone of the fibula has been fashioned into a ‘U’-shaped arch with two sets of osteotomies
 

Figure 3. (a) The anterolateral thigh (ALT) flap is being used for both intraoral lining and skin cover, thus the segment that will be covered by the lower lip remnant is de-epithelialised. (b) The lip is sutured to the ALT flap
 

Figure 4. The postoperative appearance at 2 weeks after discharge
 
Results
All tumours were stage T4a, with nodal status ranging from N0-N3 (Table). During the study period, there were six male and six female patients who had double free flap surgery. Their ages ranged from 31 to 88 (mean, 55) years. In 10 of them, a free fibula flap was combined with an ALT flap harvested from the same limb; in eight of them a skin island was harvested with the bone. One patient had bilateral ALT flaps for reconstruction of an extensive tumour of the tongue and floor of the mouth without bone involvement. Another patient had a free fibula flap combined with an anteromedial thigh flap, due to absence of suitable perforators upon dissecting the ALT flap.
 

Table. Details of patients undergoing reconstruction with double free flaps
 
 
The mean total operating time was 660 minutes, which included the time for frozen section results. Postoperative hospital stays ranged from 11 to 82 days; nine patients were discharged home within 3 weeks. Patient 10 stayed 80 days. She declined further surgery for an intraoral dehiscence, which was therefore treated conservatively. Patient 7 stayed 82 days, as his recovery was complicated by a carotid blowout on the 11th postoperative day for which he had a surgery; subsequently a pseudomonas wound infection was treated with antibiotics. After surgery, seven patients were able to resume oral feeding sufficient to maintain their body weight; the remainder relied on tube feeding. Five patients received adjuvant treatment (4 had chemoradiation and 1 only had radiotherapy).
 
Minor postoperative complications (fluid collections, fistulae) occurred in 67% of these patients and usually resolved with conservative management. More serious complications occurred in 33% of the patients (carotid blowout, wound dehiscence/infection, and fluid collections treated surgically). In one patient, a haematoma was treated by debridement of the soft tissue portion of the free fibula flap that had been de-epithelialised and ‘buried’. There were no instances of total flap loss; two patients were taken back to theatre for exploration and their flaps were salvaged. One of them (patient 10) had venous congestion of the fibula skin flap (used for intraoral lining), which was salvaged but remained swollen and indurated. In view of a concomitant intraoral wound dehiscence, the swollen skin island was debrided and a pedicled ipsilateral pectoralis major flap was harvested to close the intraoral wound. Regrettably, although the pedicled flap survived, the intraoral wound dehisced again, and the patient declined to have further surgery so her wound was managed with daily dressings (see above).
 
Two (17%) out of the 12 patients had tumour recurrence during the follow-up period, and a further two (17%) had distant metastases. Survival from the time of surgery ranged from 60 to 303 days. The patient survival rate at 6 months was 91%, and at 1 year was 64%. At the time of writing this paper, only seven of the 12 patients had been followed up for at least 2 years, three (43%) of whom were still alive.
 
Discussion
Following resection of advanced oral cancers, it is our standard practice to use double free flaps when needed for reconstruction of complex oromandibular defects, particularly those involving large defects of both bone and soft tissue. In most cases, the indication for double free flaps was the requirement for bone and soft tissue/skin not provided by the skin island of a FO flap. This practice is by no means universal; some surgeons are reluctant to contemplate a second free flap due to the perceived increase in technical complexity, operating time, and risk of complications. Alternative strategies include substitution of the fibular flap with a metal reconstruction plate, combined with a soft tissue flap for resurfacing7; combining a fibular free flap with pedicled regional flaps, such as the deltopectoral flap, PMMF,8 or latissimus dorsi myocutaneous flap. Some centres regard such cases as ‘inoperable’ and offer palliative treatment only.
 
However, these simpler alternatives have their drawbacks. The problems associated with an alloplastic plate with a soft tissue flap for composite mandible reconstruction are well documented,9 10 11 there being high rates of delayed plate exposure and recourse to salvage procedures.12 In the long term, use of vascularised bone (particularly in the FO flap) is more successful for mandible reconstruction,2 and was our first choice in all cases, with the possible exception of patients with a short life expectancy (<6 months). Recourse to a regional pedicled soft tissue flap instead of a free flap is based on its perceived advantage in being technically easier to harvest and involving shorter operating times.9 13 There is also a perceived lower risk of complications through avoiding a second set of microanastomoses. The PMMF is the most commonly used regional flap,14 but the vascularity of its skin paddle (like that of other regional flaps used in head and neck reconstruction) tends to be suboptimal; if the muscle is too short, more of the skin paddle results in a ‘random-pattern’. Crucially, the skin islands tend to be positioned at the most distal portions and thus have the poorest vascularity in the most critical parts.15 Chen et al16 recommends avoiding PMMFs to line the oral cavity due to a high rate of bone exposure from dehiscence.
 
On the contrary, surgeons such as Bianchi et al17 have actually demonstrated better outcomes with double free flaps compared to a combination of one free flap with one pedicled flap. The bulk of the muscle pedicle in regional flaps can interfere with the inset and vascularity of a concomitant free flap,13 and the tendency for muscle atrophy and gravitational effects can adversely affect the final results of reconstruction. Chen et al16 demonstrated a lower failure rate with two free flaps (2.8%) compared with the combination of one free and one pedicled flap (9%). They speculated that the bulky PMMF pedicle may actually compress the free flap pedicle, citing the 14% to 33% frequency of internal jugular vein thrombosis after radical neck dissection covered with pedicled flaps.18 19 The skin island of a regional flap also tends to be thicker, less pliable, and thus may interfere with intraoral function. Regional flaps may be limited in other ways (eg lack of necessary tissue components or specific tissue volume), which compromise the final aesthetic and functional outcomes.20
 
Although on average, a single free flap can take 1.5 hours longer than a PMMF to harvest, Tsue et al21 found that the operating time for double flaps can be 3 hours shorter than for a one free and one pedicled combination. They explained this by citing possible bias by surgeons choosing to use a second pedicled flap, when the resection time was longer, and surgeons working faster whenever two free flaps were anticipated. Guillemaud et al22 found no significant difference in the duration of surgery and complication rate when comparing double free and one free and one pedicled surgeries. In the end, the duration of surgery should not be a factor in determining the type of reconstruction.23
 
Proposed indications for the use of double free flaps are listed in the Box.20 The reconstruction of defects resulting from tumour resection in the head and neck region is a challenge, particularly when a composite of tissues is required or the defect is too large to cover by a single flap. Recourse to two free flaps allows more versatility and flexibility when reconstructing such complex defects. The best osseous and soft tissue elements may be independently selected, yielding appropriate tissue characteristics for ideal defect reconstruction. Using two separate thin pliable free flaps rather than bulky pedicled flaps may allow easier insetting and better restoration of the 3-dimensional anatomical boundaries,24 and thus both the functional and aesthetic outcomes can be addressed. With free flaps, there is also the potential for including other components such as nerves for sensate flaps.24
 

Box. Indications for the use of double free flap reconstruction
 
Good-quality soft tissue coverage is needed to reduce the risk of plate exposure12; even when the skin component of the FO flap can provide adequate surface cover, there is usually an overall shortage of soft tissue. Soft tissue reconstruction is as important as bone reconstruction25 in determining a satisfactory outcome, as deficiency of the latter tissues is poorly tolerated in the head and neck,26 and may lead to inadequate obliteration of dead spaces (eg from resection of masticators, buccal fat pad, and parotid). This causes accumulation of fluid which may become secondarily infected,16 and threaten micro-anastomoses and lead to contractures, and poor cosmetic outcomes or functionality that can lead to trismus, as well as contraction of the floor of the mouth with tethering of the tongue with difficulties in swallowing and speech.27 Therefore, even in the absence of bone loss, a double free flap reconstruction can be advantageous especially if soft tissue loss is substantial or beyond the reach of pedicled alternatives.
 
The use of two simultaneous free flaps undoubtedly poses technical difficulties, by increasing potential patient morbidity and is time-consuming. Although it is not our intention to promote double free flap reconstruction as a ‘routine’ reconstruction procedure, we wish to highlight it as an option, at least for tumours that are often deemed ‘inoperable’. Balasubramanian et al28 demonstrated that advanced ‘inoperable’ tumours such as T4b (in 7 of 21 cases) can be safely operated on; having double free flap reconstruction in the armamentarium allows surgeons to be more aggressive with extirpation. With careful patient selection, the duration of surgery, hospital stays, and complications need not be prohibitive compared to single free flap operations.25 Wei et al20 suggest that double free flaps should be restricted to patients with primary cancers, avoiding their use in those with recurrent cancers or second primaries. Nevertheless, in our series three patients presented with recurrent cancer. Individual patients should be assessed on a case-by-case basis—a PMMF could be considered to cover the skin of the neck, whilst reconstruction plates may be used to reconstruct short posterior or lateral mandible defects, particularly in those with a short life expectancy.
 
Our study shows that double free flap reconstruction can be worthwhile in patients with T4 tumours with a flap survival rate of 100% and a patient survival rate of 64% at the time of going to press. Just over half of our patients were able to resume oral feeding, which is somewhat lower than that in some other studies,28 29 and may be related to the locally advanced extent of their tumours, particularly with regard to tongue involvement.
 
References
1. Hidalgo DA, Rekow A. A review of 60 consecutive fibula free flap mandible reconstructions. Plast Reconstr Surg 1995;96:585-96. CrossRef
2. Tan BK, Wong CH. An anomalous septocutaneous perforator to the skin paddle of the fibula osteocutaneous flap originating from the posterior tibial artery. J Plast Reconstr Aesthet Surg 2009;62:690-2. CrossRef
3. Chiu T, Wong EW, Burd A, Vlantis A. Perforator transfer in the antero-lateral thigh flap. J Plast Reconstr Aesthet Surg 2013;66:1012-3. CrossRef
4. Lin PY, Kuo YR, Chien CY, Jeng SF. Reconstruction of head and neck cancer with double flaps: comparison of single and double recipient vessels. J Reconstr Microsurg 2009;25:191-5. CrossRef
5. Wei FC, Demirkan F, Chen HC, Chen IH. Double free flaps in reconstruction of extensive composite mandibular defects in head and neck cancer. Plast Reconstr Surg 1999;103:39-47. CrossRef
6. Wei FC, Celik N, Chen HC, Cheng MH, Huang WC. Combined anterolateral thigh flap and vascularized fibula osteoseptocutaneous flap in reconstruction of extensive composite mandibular defects. Plast Reconstr Surg 2002;109:45-52. CrossRef
7. Boyd JB, Mulholland RS, Davidson J, et al. The free flap and plate in oromandibular reconstruction: long-term review and indications. Plast Reconstr Surg 1995;95:1018-28. CrossRef
8. Ariyan S. The pectoralis major myocutaneous flap. A versatile flap for reconstruction in the head and neck. Plast Reconstr Surg 1979;63:73-81. CrossRef
9. Blackwell KE, Buchbinder D, Urken ML. Lateral mandibular reconstruction using soft-tissue free flap and plates. Arch Otolaryngol Head Neck Surg 1996;122:672-8. CrossRef
10. Cohen M, Schultz RC. Mandibular reconstruction. Clin Plast Surg 1985;12:411-22.
11. Shpitzer T, Gullane PJ, Neligan PC, et al. The free vascularized flap and the flap plate option: comparative results of reconstruction of lateral mandibular defects. Laryngoscope 2000;110:2056-60. CrossRef
12. Wei FC, Celik N, Yang WG, Chen IH, Chang YM, Chen HC. Complications after reconstruction plate and soft-tissue free flap in composite mandibular defects and secondary salvage reconstruction with osteocutaneous flap. Plast Reconstr Surg 2003;112:37-42. CrossRef
13. Blackwell KE, Buchbinder D, Biller HF, Urken ML. Reconstruction of massive defects in the head and neck: the role of simultaneous distant and regional flaps. Head Neck 1997;19:620-8. CrossRef
14. Lerrick AJ, Zak MJ. Oral cavity reconstruction with simultaneous free and pedicled composite flaps. Operat Tech Otolaryngol Head Neck Surg 2000;11:76-89. CrossRef
15. Shah JP, Haribhakti V, Loree TR, Sutaria P. Complications of the pectoralis major myocutaneous flap in head and neck reconstruction. Am J Surg 1990;160:352-5. CrossRef
16. Chen HC, Demirkan F, Wei FC, Cheng SL, Cheng MH, Chen IH. Free fibula osteoseptocutaneous-pedicled pectoralis major myocutaneous flap combination in reconstruction of extensive composite mandibular defects. Plast Reconstr Surg 1999;103:835-45. CrossRef
17. Bianchi B, Ferri A, Ferrari S, et al. Reconstruction of lateral through and through oro-mandibular defects following oncological resections. Microsurgery 2010;30:517-25. CrossRef
18. Fisher CB, Mattox DE, Zinreich JS. Patency of the internal jugular vein after functional neck dissection. Laryngoscope 1988;98:923-7. CrossRef
19. Brown DH, Mulholland S, Yoo JH, et al. Internal jugular vein thrombosis following modified neck dissection: implications for head and neck flap reconstruction. Head Neck 1998;20:169-74. CrossRef
20. Wei FC, Yazar S, Lin CH, Cheng MH, Tsao CK, Chiang YC. Double free flaps in head and neck reconstruction. Clin Plastic Surg 2005;32:303-8. CrossRef
21. Tsue TT, Desyatnikova SS, Deleyiannis FW, et al. Comparison of cost and function in reconstruction of the posterior oral cavity and oropharynx. Free vs pedicled soft tissue transfer. Arch Otolaryngol Head Neck Surg 1997;123:731-7. CrossRef
22. Guillemaud JP, Seikaly H, Cote DW, et al. Double free-flap reconstruction: indications, challenges, and prospective functional outcomes. Arch Otolaryngol Head Neck Surg 2009;135:406-10. CrossRef
23. Schusterman MA, Horndeski G. Analysis of the morbidity associated with immediate microvascular reconstruction in head and neck cancer patients. Head Neck 1991;13:51-5. CrossRef
24. Urken ML, Weinberg H, Vickery C, et al. The combined sensate radial forearm and iliac crest free flaps for reconstruction of significant glossectomy-mandibulectomy defects. Laryngoscope 1992;102:543-8. CrossRef
25. Urken ML, Weinberg H, Vickery C, Buchbinder D, Lawson W, Biller HF. Oromandibular reconstruction using microvascular composite free flaps. Reports of 71 cases and a new classification scheme for bony, soft-tissue, and neurologic defects. Arch Otolaryngol Head Neck Surg 1991;117:733-44. CrossRef
26. Andrades P, Bohannon IA, Baranano CF, Wax MK, Rosenthal E. Indications and outcomes of double free flaps in head and neck reconstruction. Microsurgery 2009;29:171-7. CrossRef
27. Urken ML, Buchbinder D, Weinberg H, et al. Functional evaluation following microvascular oromandibular reconstruction of the oral cancer patient: a comparative study of reconstructed and non-reconstructed patients. Laryngoscope 1991;101:935-50. CrossRef
28. Balasubramanian D, Thankappan K, Kuriakose MA, et al. Reconstructive indications of simultaneous double free flaps in the head and neck: a case series and literature review. Microsurgery 2012;32:423-30. CrossRef
29. Hanasono MM, Weinstock YE, Yu P. Reconstruction of extensive head and neck defects with multiple simultaneous free flaps. Plast Reconstr Surg 2008;122:1739-46. CrossRef

The association between clinical parameters and glaucoma-specific quality of life in Chinese primary open-angle glaucoma patients

Hong Kong Med J 2014 Aug;20(4):274–8 | Epub 28 Feb 2014
DOI: 10.12809/hkmj134062
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
The association between clinical parameters and glaucoma-specific quality of life in Chinese primary open-angle glaucoma patients
Jacky WY Lee, FRCS1; Catherine WS Chan, MPhil1; Jonathan CH Chan, FRCS2; Q Li, PhD1; Jimmy SM Lai, MD1
1 Department of Ophthalmology, The University of Hong Kong, Pokfulam, Hong Kong
2 Department of Ophthalmology, Queen Mary Hospital, Pokfulam, Hong Kong
 
Corresponding author: Dr Jacky WY Lee (jackywylee@gmail.com)
 Full paper in PDF
Abstract
Objective: To investigate the association between clinical measurements and glaucoma-specific quality of life in Chinese glaucoma patients.
 
Design: Cross-sectional study.
 
Setting: An academic hospital in Hong Kong.
 
Patients: A Chinese translation of the Glaucoma Quality of Life–15 questionnaire was completed by 51 consecutive patients with bilateral primary open-angle glaucoma. The binocular means of several clinical measurements were correlated with Glaucoma Quality of Life–15 findings using Pearson’s correlation coefficient and linear regression. The measurements were the visual field index and pattern standard deviation from the Humphrey Field Analyzer, Snellen best-corrected visual acuity, presenting intra-ocular pressure, current intra-ocular pressure, average retinal nerve fibre layer thickness via optical coherence tomography, and the number of topical anti-glaucoma medications being used.
 
Results: In these patients, there was a significant correlation and linear relationship between a poorer Glaucoma Quality of Life–15 score and a lower visual field index (r=0.3, r2=0.1, P=0.01) and visual acuity (r=0.3, r2=0.1, P=0.03). A thinner retinal nerve fibre layer also correlated with a poorer Glaucoma Quality of Life–15 score, but did not attain statistical significance (r=0.3, P=0.07). There were no statistically significant correlations for the other clinical parameters with the Glaucoma Quality of Life–15 scores (all P values being >0.7). The three most problematic activities affecting quality of life were “adjusting to bright lights”, “going from a light to a dark room or vice versa”, and “seeing at night”.
 
Conclusion: For Chinese primary open-angle glaucoma patients, binocular visual field index and visual acuity correlated linearly with glaucoma-specific quality of life, and activities involving dark adaptation were the most problematic.
 
 
New knowledge added by this study
  • A lower visual field index and poorer visual acuity correlated with a poorer glaucoma-specific quality of life in Chinese primary open-angle glaucoma patients.
  • The most problematic activities affecting quality of life in glaucoma patients were “adjusting to bright lights”, “going from a light to a dark room or vice versa”, and “seeing at night”.
Implications for clinical practice or policy
  • In busy clinical settings, the visual field index serves as a quick reference for glaucoma-specific quality of life, and can identify patients who may warrant more formal assessment for psychosocial support.
  • Lifestyle modifications for glaucoma patients can include more light in dark areas and adjusting curtains and mirrors to reduce glare, so as to make the transition from different lighting conditions more acceptable.
 
Introduction
In clinical practice, much time is spent on measuring the clinical parameters of glaucoma including the intra-ocular pressure (IOP), visual acuity (VA), visual field, and retinal nerve fibre layer (RNFL) thickness. What is often neglected is the quality of life (QOL) of patients and how well they live with their disease on a day-to-day basis. Glaucoma affects 80 million people worldwide.1 It is a chronic and irreversible disease with a heavy burden on visual function and vision, besides being one of the most important constituents affecting QOL.2 3 4
 
Recourse to QOL questionnaires in glaucoma can be broadly divided into general health–related, vision-specific, or glaucoma-specific.5 Quality-of-life assessment in glaucoma patients is as important as the clinical parameters used to measure glaucoma progression, because it reflects the impact of the ocular disease on the patient as a whole and may also be an indicator of whether the disease is advancing.4 6 7 8 9
 
Using generic QOL assessments, glaucoma was found to have deleterious impact as other systemic chronic diseases like osteoporosis, diabetes, or dementia.10 However, such generic tests do not address the end points of glaucoma, such as visual impairment and visual field constriction, for which reason their robustness and specificity are limited.10 There are approximately 18 different patient-reported QOL assessments specific to glaucoma. Among these, the Glaucoma Quality of Life–15 Questionnaire (GQL-15) and the Vision and Quality of Life Index have been found most satisfactory in terms of content, validity, and reliability.11 Thus, the aim of this study was to investigate the correlations between clinical parameters and glaucoma-specific QOL in Chinese patients with bilateral primary open-angle glaucoma (POAG).
 
Methods
For this cross-sectional study, consecutive patients with bilateral POAG were recruited from an academic hospital in Hong Kong. The diagnosis of POAG was based on an open angle on gonioscopy, a presenting IOP of >21 mm Hg, and either a glaucomatous visual field loss on at least two Humphrey visual field tracings using the 24-2 SITA fast protocol (Humphrey Instruments, Inc, Zeiss Humphrey, San Leandro [CA], US) or RNFL thinning on Spectralis Optical Coherence Tomography (Heidelberg Engineering, Carlsbad [CA], US). Patients were excluded if they had unilateral disease, concomitant ocular diseases that significantly affected their vision (amblyopia, mature cataract affecting the accuracy of glaucoma investigations). Patients were also excluded if they had other corneal or retinal pathologies, or if they were unable to yield reliable visual field results. Their IOPs were determined using Goldmann applanation tonometry.
 
The GQL-15 questionnaire is glaucoma-specific, and assesses patient-perceived visual disability in 15 daily tasks responded to in writing. The tasks addressed four aspects of visual disability: (1) central and near vision; (2) peripheral vision; (3) dark adaptation and glare; and (4) outdoor mobility. A 5-point rating scale for the level of difficulty of each task can yield a total score of 0 to 75. Higher scores signify a lower QOL. The GQL-15 was translated into traditional Chinese text and distributed to participating patients. For illiterate patients, the items were read out to them in Cantonese dialect. The questionnaire was translated from English to Chinese by an investigator who was fluent in both English and Chinese. The translated questionnaire was checked for discrepancies by a second investigator and a consensus was reached to develop a draft Chinese questionnaire. A third investigator then back-translated the draft Chinese questionnaire into English; the back-translated draft and the original version were then compared. Discrepancies were amended and gave rise to the final Chinese version. The questionnaire was then tested on five POAG patients of varying gender and age. Patients were asked to complete the questionnaire, and offer their own interpretation of its contents and whether any alternative wording should be used.
 
The D’Agostino-Pearson omnibus test was used to test for normality. Nearly half of the parameters passed the normality testing. The means of several clinical parameters were calculated for the two eyes and correlated with the GQL-15 using Pearson’s correlation coefficient and linear regression analysis. The selected parameters were the visual field index (VFI) and pattern standard deviation (PSD) from the Humphrey Field Analyzer, the Snellen best-corrected VA, the presenting IOP, current IOP, average RNFL thickness via optical coherence tomography, as well as the number of topical anti-glaucoma medications being used. t Tests were used to test for differences between the mean GQL-15 scores between males and females. Data were expressed as mean ± standard deviation (SD). Any P value of <0.05 was accepted as statistically significant.
 
Our institutional review board granted ethics approval for the study and informed consent was obtained from each patient prior to the start of the study.
 
Results
Fifty-one patients with bilateral POAG were recruited, all of whom were Chinese. Their mean (± SD) age was 65.8 ± 12.1 years and the male-to-female ratio was 1.1:1.
 
The means of their clinical parameters for both eyes are shown in the Table. Their mean GQL-15 score was 26.0 ± 11.6 (out of 75). The three most problematic activities reported for all patients belonged to: item 4 “adjusting to bright lights” (mean score, 2.3 ± 1.3); item 6 “going from a light to a dark room or vice versa” (mean score, 2.3 ± 1.3); and item 2 “seeing at night” (mean score, 2.2 ± 1.2).
 

Table. Clinical parameters for both eyes of the patients
 
There was a moderately significant correlation between a lower VFI and a poorer GQL-15 score (r=0.3, P=0.01; Fig 1). Likewise, a poorer VA correlated significantly with a poorer GQL-15 score (r=0.3, P=0.03; Fig 2). These two correlations seemed to follow a linear pattern such that linear regression analysis showed a weak linear relationship between a poorer GQL-15 score and a lower VFI (r2=0.1, P=0.01) and a poorer VA (r2=0.1, P=0.03).
 

Fig 1. Correlation between Glaucoma Quality of Life–15 questionnaire (GQL-15) and visual field index
 

Fig 2. Correlation between Glaucoma Quality of Life–15 questionnaire (GQL-15) and visual acuity
 
A thinner RNFL appeared to be associated with a poorer GQL-15 score but the correlation did not attain statistical significance (r=0.3, P=0.07). In terms of pressure control, a higher presenting IOP showed a trend towards correlation with a poorer GQL-15 score (r=0.2) as did a lower current IOP (r= 0.2) and a greater number of anti-glaucoma eye drops used (r=0.1). However, none of these correlations reached statistical significance (all P>0.7). On comparing GQL-15 scores between male and female glaucoma patients, no significant difference was found (P=0.3, t test).
 
Discussion
Various studies have associated QOL with visual field impairment.8 12 Odberg et al13 simply categorised visual field defects into “normal”, “having a restricted scotoma”, or “having a field defect large enough to be of visual significance”, and found a weak-to-moderate correlation between such visual field defects and subjective visual disabilities. The Collaborative Initial Glaucoma Treatment Study later found that at the time of diagnosis, patients’ visual fields correlated only modestly with a health-related QOL questionnaire and that of VFIs; mean deviation (MD) showed better correlation with QOL than PSD, corrected pattern SD, or short-term fluctuation.14 Nelson et al4 found that the GQL-15 scores, and especially the subsets pertaining to glare, correlated significantly with MD, even for patients with mild disease. Furthermore, those with moderate and severe visual field loss had similar GQL-15 scores, suggesting a threshold for disability may be reached up to a certain level of glaucoma severity4 or represent adaptation to loss of visual function. Similarly, Goldberg et al15 have found that the GQL-15 scores correlated with VA, MD, the number of binocular points of <10 dB, and that QOL tended to decrease with disease severity. Whilst MD is commonly correlated with QOL in glaucoma patients, it has the drawback of not being specific enough to represent the limitations caused by glaucoma alone, since it may also be affected by global defects like cataract. On the other hand, using PSD eliminates the factor of global defects, though it is not sensitive in advanced glaucoma, where the entire field is globally depressed.
 
Thus in this study, we utilised the VFI, which is a percentage summarising the overall visual field status compared to age-adjusted visual fields. The VFI emphasises the importance of the central field. It is less affected by media opacities (cataracts), and is more accurate than MD for monitoring glaucoma progression.16 17 Few studies have used VFI to correlate with QOL in glaucoma. Sawada et al18 reported that VFI correlated with QOL via the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) and that the correlation was better than with MD. Our study found a statistically significant correlation between the reduction in mean binocular VFI and a poorer GQL-15 score and that VFI was a better indicator of glaucoma-specific QOL than RNFL thickness, IOP, or PSD on visual field. We chose to use PSD rather than MD in our analysis because the latter could be affected by any global obstruction to vision like cataract, whereas PSD is more specific for inter-field variability. However, the two clinical parameters that achieved a significant correlation with the GQL-15 score were binocular VFI and VA, and both parameters were also associated with the GQL-15 score in a linear manner.
 
Intra-ocular pressure control did not correlate significantly with QOL although a higher IOP on presentation seemed to produce a lower QOL score, and interestingly a lower current IOP seemed to correlate with a poorer QOL. This unique finding may indicate that those with a lower current IOP have had glaucoma for longer or have more advanced disease warranting more aggressive pressure reduction. Furthermore, those using more anti-glaucoma eye drops seemed to have a lower QOL score, but these correlations were weak and did not reach statistical significance.
 
Patient perceptions of disease and methods of coping are heavily influenced by culture and ethnicity. Thus, Singapore Chinese glaucoma patients were more accepting of their daily disabilities than corresponding American Caucasians.19 Literature pertaining to Chinese glaucoma patients is sparse. Wu et al20 found that Chinese glaucoma patients were particularly concerned about the uncertainties of treatment, the prognosis, and passing on of the disease to family members. Lin and Yang21 reported a correlation with MD and the Medical Outcomes Study Short-Form 36 Health Survey and the NEI VFQ-25. Whilst clinical data provide evidence of structural and functional damage of the optic nerve, they do not address the impact of disease on patients. The correlation of objective clinical measurements to QOL is particularly useful, because it gives ophthalmologists in a busy clinical setting an overall impression of glaucoma-specific QOL. This can enable them to recommend environmental and lifestyle modifications to minimise obstacles and maximise the period of independence.5 Our study found that in Chinese glaucoma patients, the most problematic aspects of coping were “adjusting to bright lights”, “going from a light to a dark room or vice versa”, and “seeing at night”. Interestingly, all these activities belong to the realm of dark adaptation. Hence, environmental modifications can potentially help to reduce glare.4 Furthermore, an estimation of QOL from clinical parameters can allow ophthalmologists to more readily identify patients with a poorer QOL needing more psychosocial support. Interestingly, it has been reported that POAG itself is associated with anxiety, depression, and hypochrondriasis22 and a low GQL-15 score has also been identified as a predictor for depression.23
 
One limitation of our study was that it was cross-sectional and looked at POAG patients with varying degrees of severity. A longitudinal study would have provided additional information about the changes in QOL throughout different stages of the disease. A second limitation was that the population received heterogeneous treatments (lasers and surgeries). However, as the aim of this study did not involve evaluating the side-effects of glaucoma treatments and since the GQL-15 too did not target treatment side-effects, we did not consider it necessary to exclude those who had undergone such treatments previously. Rather, we opted to include a more heterogeneous POAG population to make the results more generalisable and representative. A third limitation was that no single test is perfect; the GQL-15 mainly focuses on visual activities, which is only one aspect of QOL. Conceivably, such a questionnaire only reflects patient confidence to perform certain tasks rather than the actual difficulties experienced. Nevertheless, it has been shown that patients’ loss of confidence often precedes their perceptions of difficulty.24
 
To the best of our knowledge, this is one of the few studies reporting a significant correlation and a linear relationship between VFI and the glaucoma-specific GQL-15 score in the Chinese POAG patients. This study also identified dark adaptation as the most challenging visual issue pertinent to Chinese POAG patients.
 
Declaration
No conflicts of interest were declared by the authors.
 
References
1. Mansberger SL, Demirel S. Early detection of glaucomatous visual field loss: why, what, where, and how. Ophthalmol Clin North Am 2005;18:365-73, v-vi. CrossRef
2. Beauchamp CL, Beauchamp GR, Stager DR Sr, Brown MM, Brown GC, Felius J. The cost utility of strabismus surgery in adults. J AAPOS 2006;10:394-9. CrossRef
3. Brown GC, Brown MM, Sharma S, et al. The burden of age-related macular degeneration: a value-based medicine analysis. Trans Am Ophthalmol Soc 2005;103:173-86.
4. Nelson P, Aspinall P, Papasouliotis O, Worton B, O’Brien C. Quality of life in glaucoma and its relationship with visual function. J Glaucoma 2003;12:139-50. CrossRef
5. Spaeth G, Walt J, Keener J. Evaluation of quality of life for patients with glaucoma. Am J Ophthalmol 2006;141(1 Suppl):S3-14. CrossRef
6. Jampel HD, Schwartz A, Pollack I, Abrams D, Weiss H, Miller R. Glaucoma patients' assessment of their visual function and quality of life. J Glaucoma 2002;11:154-63. CrossRef
7. Janz NK, Wren PA, Lichter PR, Musch DC, Gillespie BW, Guire KE. Quality of life in newly diagnosed glaucoma patients: the Collaborative Initial Glaucoma Treatment Study. Ophthalmology 2002;108:887-97; discussion 898. CrossRef
8. Parrish RK 2nd, Gedde SJ, Scott IU, et al. Visual function and quality of life among patients with glaucoma. Arch Ophthalmol 1997;115:1447-55. CrossRef
9. Gutierrez P, Wilson MR, Johnson C, et al. Influence of glaucomatous visual field loss on health-related quality of life. Arch Ophthalmol 1997;115:777-84. CrossRef
10. Mills T, Law SK, Walt J, Buchholz P, Hansen J. Quality of life in glaucoma and three other chronic diseases: a systematic literature review. Drugs Aging 2009;26:933-50. CrossRef
11. Vandenbroeck S, De Geest S, Zeyen T, Stalmans I, Dobbels F. Patient-reported outcomes (PRO's) in glaucoma: a systematic review. Eye (Lond) 2011;25:555-77. CrossRef
12. Lee BL, Gutierrez P, Gordon M, et al. The Glaucoma Symptom Scale. A brief index of glaucoma-specific symptoms. Arch Ophthalmol 1998;16:861-6. CrossRef
13. Odberg T, Jakobsen JE, Hultgren SJ, Halseide R. The impact of glaucoma on the quality of life of patients in Norway. II. Patient response correlated to objective data. Acta Ophthalmol Scand 2001;79:121-4. CrossRef
14. Mills RP, Janz NK, Wren PA, Guire KE. Correlation of visual field with quality-of-life measures at diagnosis in the Collaborative Initial Glaucoma Treatment Study (CIGTS). J Glaucoma 2001;10:192-8. CrossRef
15. Goldberg I, Clement CI, Chiang TH, et al. Assessing quality of life in patients with glaucoma using the Glaucoma Quality of Life–15 (GQL-15) questionnaire. J Glaucoma 2009;18:6-12. CrossRef
16. Bengtsson B, Heijl A. A visual field index for calculation of glaucoma rate of progression. Am J Ophthalmol 2008;145:343-53. CrossRef
17. Casas-Llera P, Rebolleda G, Muñoz-Negrete FJ, Arnalich-Montiel F, Pérez-López M, Fernández-Buenaga R. Visual field index rate and event-based glaucoma progression analysis: comparison in a glaucoma population. Br J Ophthalmol 2009;93:1576-9. CrossRef
18. Sawada H, Fukuchi T, Abe H. Evaluation of the relationship between quality of vision and the visual function index in Japanese glaucoma patients. Graefes Arch Clin Exp Ophthalmol 2011;249:1721-7. CrossRef
19. Saw SM, Gazzard G, Au Eong KG, Oen F, Seah S. Utility values in Singapore Chinese adults with primary open-angle and primary angle-closure glaucoma. J Glaucoma 2005;14:455-62. CrossRef
20. Wu PX, Guo WY, Xia HO, Lu HJ, Xi SX. Patients' experience of living with glaucoma: a phenomenological study. J Adv Nurs 2011;67:800-10. CrossRef
21. Lin JC, Yang MC. Correlation of visual function with health-related quality of life in glaucoma patients. J Eval Clin Pract 2010;16:134-40. CrossRef
22. Erb C, Thiel HJ, Flammer J. The psychology of the glaucoma patient. Curr Opin Ophthalmol 1998;9:65-70. CrossRef
23. Skalicky S, Goldberg I. Depression and quality of life in patients with glaucoma: a cross-sectional analysis using the Geriatric Depression Scale–15, assessment of function related to vision, and the Glaucoma Quality of Life–15. J Glaucoma 2008;17:546-51. CrossRef
24. Nelson P, Aspinall P, O’Brien C. Patients’ perception of visual impairment in glaucoma: a pilot study. Br J Ophthalmol 1999;83:546-52. CrossRef

Current management practice for bladder cancer in Hong Kong: a hospital-based cross-sectional survey

Hong Kong Med J 2014;20:229–33 | Number 3, June 2014 | Epub 28 Mar 2014
DOI: 10.12809/hkmj134064
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Current management practice for bladder cancer in Hong Kong: a hospital-based cross-sectional survey
Eddie SY Chan, MD, FHKAM (Surgery); CH Yee, FRCS (Edin), FHKAM (Surgery); SM Hou,FRCS (Edin), FHKAM (Surgery); CF Ng, MD, FHKAM (Surgery)
Division of Urology, Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong
 
Corresponding author: Dr Eddie SY Chan (eddie@surgery.cuhk.edu.hk)
Abstract
Objectives: To examine current practice in the management of bladder cancer in Hong Kong government and private hospitals.
 
Design: Cross-sectional survey.
 
Setting: All government hospitals and the major private institutions in Hong Kong, which provide urological services.
 
Participants: Urologists responding to an anonymous, self-administered, web-based questionnaire regarding practices in smoking cessation, treatment of non-muscle invasive bladder cancer and muscle invasive bladder cancer, and research into bladder cancer.
 
Results: Of the 29 urologists from 11 government hospitals and eight private institutions who were invited, 18 from 11 (100%) government hospitals and seven from six (75%) private institutions responded, which amounted to an 86% response rate. In all, 88% of the respondents seldom or never referred their bladder cancer patients to smoking cessation programmes. Hong Kong urologists showed good compliance in the management of non-muscle invasive bladder cancer according to international guidelines. There was great variation with regard to regimens for maintenance of intravesical immunotherapy. There was underuse of perioperative systemic chemotherapy, despite wide acceptance of this practice; fewer than 10% of the patients received neo-adjuvant and adjuvant systemic chemotherapy for the treatment of muscle invasive bladder cancer. Of the surveyed urologists, 80% expressed an inadequacy of resources for bladder cancer research and 96% agreed that a local inter-hospital bladder cancer database was needed.
 
Conclusions: This study demonstrated great diversity in the use of intravesical immunotherapy, perioperative systemic chemotherapy, and surgical treatment of bladder cancer among urology service providers. There is a need for clear recommendations in these areas.
 
 
New knowledge added by this study
  • By providing important information on practice preferences in the management of bladder cancer in both the public and private sectors in Hong Kong, this study demonstrates the great diversity in the use of intravesical immunotherapy, perioperative systemic chemotherapy, and surgical treatments.
Implications for clinical practice or policy
  • Local guidelines in bladder cancer management and the use of intravesical bacillus Calmette-Guérin are needed.
 
Introduction
Bladder cancer is a common genitourinary malignancy. It is the fifth most frequent cancer in the US, where it accounts for 7% of all incident malignancies.1 In 2009, there were 372 newly diagnosed bladder cancer cases in Hong Kong.2 Patients with bladder cancer warrant close surveillance because of high recurrence and progression rates (50-70%).3 Due to its prolonged natural history, intensive follow-up and treatment strategies, management of this cancer is costly and is the most expensive malignancy to treat on a per-patient basis.4 5
 
Guidelines for bladder cancer management have been established in an attempt to improve treatment outcomes. The most commonly used are the American Urological Association (AUA), European Association of Urology (EAU), and National Comprehensive Cancer Network (NCCN) guidelines. There is no specific guideline in Hong Kong. The practice in bladder cancer treatment in Hong Kong may differ among urologists and centres. The aim of this survey was to gain better understanding of current bladder cancer management practice in Hong Kong.
 
Methods
Questionnaire and data collection
An online multiple-choice questionnaire was sent to all government hospitals and major private institutions providing urological services. Senior urologists from corresponding hospitals were invited to respond to the questionnaire, which was anonymous, self-administrated, and non-validated. From each centre at least one urologist was encouraged to respond. If the hospital or centre had three or more board-certified urologists, no more than two were encouraged to complete the survey, so as to be as representative as possible. The responses from the surveyed urologists were submitted and collected over a secured connection.
 
The questionnaire comprised 30 questions divided into three sections: (1) General Issues and Smoking Cessation, (2) Management and Treatment, and (3) Bladder Cancer Research. The first part concerned the daily workload for bladder cancer and smoking cessation programmes. The second part (the main part of the survey) evaluated management preferences for non-muscle invasive bladder cancers (NMIBCs) and muscle invasive bladder cancers (MIBCs), and included questions regarding intravesical and systemic chemotherapy. The final part addressed the adequacy of resources and progress for bladder cancer research.
 
Statistical analysis
Data were presented as descriptive statistics of the main variables and analysed using Excel (Version 14.2, California, US). A frequency table was constructed to indicate the management preferences.
 
Results
Between March and August 2012, 19 hospitals and institutions from both government (n=11) and private (n=8) sectors were involved in this study. Twenty-nine senior urologists from corresponding hospitals were invited to participate in the survey. Responses from 11 (100%) government hospitals and six (75%) private sector institutions were received. Of the 29 invited urologists, 18 were from public hospitals and 11 from private institutions; eventually, 25 (86%) responded to the survey and completed the questionnaires (18 [100%] from public hospitals and 7 [64%] from the private sector).
 
Part 1: general issues and smoking cessation
Among the surveyed urologists, 17 (68%) estimated that 10% to 25% of their clinical workload was spent on diagnosis, treatment, and surveillance of bladder cancer. Whilst cigarette smoking is a key risk factor for bladder cancer, 14 (56%) commented that there was no access to a smoking cessation programme in their hospitals. Notably, 22 (88%) seldom or never referred their patients to any smoking cessation programme. Only 11 (44%) and 10 (40%) of the respondents thought that resources for smoking cessation were readily or easily available to patients and urologists, respectively.
 
Part 2: management and treatment
Guidelines from AUA and EAU remain the most useful guides for bladder cancer management. None of the surveyed urologists used the guideline published by the Chinese Urological Association. However, 12 (48%) of the respondents had a bladder cancer management guideline in their own hospital and 15 (60%) expressed the need for a local Hong Kong guideline.
 
Among the surveyed hospitals, immediate intravesical chemotherapy was always (56%) or often (44%) administered. All hospitals (100%) used mitomycin C as the chemotherapeutic drug of choice. Currently, international guidelines also advocate a second transurethral resection of the bladder tumour (TURBT) for patients with high-risk NMIBC or in the absence of detrusor muscle in bladder tissue specimens. While all the respondents from government hospitals adopted this concept, five (28%) of them “always”, and 13 (72%) of them “often” performed a second TURBT. On the contrary, four (57%) of the urologists in private institutions seldom practised a second procedure. Overall, the common problems of a second TURBT encountered by urologists included a tight operation schedule (48%) and refusal by patients (16%).
 
All the surveyed hospitals always (44%) or often (56%) prescribed intravesical bacillus Calmette-Guérin (BCG) for high-risk NMIBC patients. However, there was a great variation in the duration of intravesical immunotherapy regimens in the 17 hospitals with responding urologists. The Table shows that the durations ranged from induction with no maintenance (24%), to maintenance for 3 months (6%), 1 year (35%), 1.5 years (6%), 2 years (6%), and 3 years (24%). Of the 25 surveyed urologists, 76% (n=19) encountered problems in intravesical immunotherapy, which were related to the poor patient compliance stemming from side-effects (60%) and serious BCG-related complications (16%).
 

Table. Duration of intravesical immunotherapy in different hospitals
 
Open radical cystectomy remains the most common approach in Hong Kong. Of the 17 surveyed hospitals whose urologists responded, only three (18%) government hospitals routinely practised radical cystectomy with a minimally invasive approach. Most of the surveyed urologists thought that systemic chemotherapy was useful in selected MIBC patients in neo-adjuvant (56%) and adjuvant (76%) settings. However, all but one hospital reported that less than 10% of their patients received either neo-adjuvant or adjuvant chemotherapy. The low frequency of systemic perioperative chemotherapy could be due to patient refusal or poor tolerance of systemic chemotherapy. Oncologists’ refusal to provide chemotherapy in neo-adjuvant (28%) and adjuvant (36%) settings could also be the reason (Fig).
 

Figure. Common problems encountered by urologists about neo-adjuvant and adjuvant chemotherapy
 
Part 3: bladder cancer research
Among the respondents, 13 (52%) thought that current management regimens were adequate for diagnosing and preventing bladder cancer recurrence/progression, whilst 12 (48%) felt that progress on bladder cancer treatment research was poor compared to that for renal cell and prostate cancer. Most of the respondents (80%) stated that resources for bladder cancer research were inadequate, and most (96%) also expressed a need for an inter-hospital bladder cancer database to improve patient care.
 
Discussion
Bladder cancer is among the commonest urological malignancies. Patients with bladder cancer demand close surveillance for recurrence and progression.
 
Thus, one fourth of the workload of urologists is spent on the diagnosis, treatment, and surveillance of bladder cancer patients. Because of the complicated treatment and follow-up strategies, it is also the most costly to treat,4 5 and there is a wide variation in the practice patterns and compliance to guidelines.6 In Hong Kong, bladder cancer incidence is on a decreasing trend in both sexes, but the crude mortality rate has not changed in the last decade.2 There are no data available regarding the preferred management patterns of Hong Kong urologists on bladder cancer. Herein, we report on the first cross-sectional survey of clinical practice for a specific urological disease category in Hong Kong. Such information can be important for urologists, health policy-makers, and patients.
 
Smoking is the most important preventable cause of death in Hong Kong and many countries. Diseases caused by smoking impose a heavy economic and medical burden on our society. Many countries therefore have enhanced efforts to promote smoking cessation in addition to strengthening tobacco control measures and legislation. Cigarette smoking is a well-established risk factor for bladder cancer, and accounts for up to 50% of all incident bladder cancers.7 The risk of bladder cancer in smokers is 2 to 5 times higher than that in non-smokers. Smoking cessation decreases the bladder cancer risk as well as the recurrence rate of such tumours.8 Continuing to smoke is associated with worse cancer-related outcomes than in those who quit. In this context, urologists play a vital role in influencing patient knowledge about smoking risks and encouraging cessation of the habit. Guzzo et al9 reported that 76% of bladder cancer patients in tertiary referral centres received no specific intervention to aid smoking cessation. A number of trials confirmed that interventions from trained health care professionals increase success rates in smoking cessation attempts.10 At present, there are a number of local smoking cessation clinics run by the Department of Health (Tung Wah Group of Hospitals, the Pok Oi Hospital, the Hospital Authority, and other organisations). These programmes cover a comprehensive range of activities that include smoking cessation services, education for the public, and research. In our study, 88% of the respondents seldom or never referred their patients to any smoking cessation programme, and nearly 60% claimed that smoking cessation facilities were difficult for patients and doctors to access. This is a disappointing statistic that needs to be addressed.
 
International guidelines set forth by the AUA, EAU, and NCCN are widely adopted by Hong Kong urologists. There is good consensus on the practice of second TURBT and perioperative intravesical chemotherapy between different guidelines for NMIBC patients.11 Evidence supports the use of single-dose, immediate postoperative intravesical instillation of mitomycin C to decrease tumour recurrence. Second TURBT within 6 weeks of initial resection enables better tissue sampling and reduces early tumour recurrence. A US study of 14 677 bladder cancer patients between 1997 and 2004 found that only 49 (0.33%) received immediate intravesical chemotherapy after TURBT.12 Cookson et al13 reported that 66% of the US-based urologists never used postoperative intravesical chemotherapy. Gontero et al14 evaluated the adherence to EAU guidelines in eight Italian referral centres and found that only 49% of high-risk patients underwent a repeat TURBT. A study based on SEER-Medicare data reported that only 7.7% of patients with high-grade NMIBC underwent a second TURBT.15 Hong Kong urologists appear to have excellent compliance with both intravesical chemotherapy and performance of a second TURBT in the management of NMIBC patients. Urologists in the private sector seem to achieve a lower rate of second TURBT, which may be due to patient preference, expectations, and financial concerns.
 
Intravesical instillation of BCG is a standard therapy after TURBT for intermediate or high-risk NMIBC, as there is evidence that bladder tumour recurrence or progression is prevented by such therapy.3 For optimal efficacy, an induction course followed by maintenance therapy is recommended, but the duration of maintenance therapy remains controversial. Böhle et al16 suggested that at least 1 year of maintenance BCG was required to prevent recurrence or progression. However, a meta-analysis of 20 trials was unable to determine which BCG maintenance schedule was the most effective.17 Recently, the benefit of maintenance BCG has been challenged.18 This practice is further complicated by significant toxicity and a high treatment cessation rate. Given the uncertainty surrounding the optimal intravesical immunotherapy, urologists in Hong Kong vary in how they deliver such treatment. Having a consensus on optimal intravesical BCG therapy is challenging but necessary, before further research involving randomised clinical trials is undertaken.
 
Minimally invasive (laparoscopic/robotic) surgical approaches have been widely used by local urologists, including for nephrectomy and prostatectomy. These help reduce morbidity, shorten hospital stays, and enhance recovery. Open radical cystectomy remains the standard treatment for MIBC patients. Laparoscopic or robot-assisted radical cystectomy is among the most challenging procedures and performed in a limited number of centres where the necessary experience and expertise exists.19 The situation in Hong Kong is similar, while open radical cystectomy is the most preferred approach.
 
The pattern of treatment for MIBC has changed to a multidisciplinary approach. There is growing evidence that perioperative chemotherapy provides survival benefits in such patients. Meta-analysis suggests that neo-adjuvant and probably adjuvant systemic chemotherapy too increase cancer-specific and overall survivals.20 21 Porter et al22 reported that only 2.6% of stage 2 and 12.7% of stage 4 patients with bladder cancer received either neo-adjuvant or adjuvant chemotherapy. The underutilisation of perioperative systemic therapy was also observed in our survey. Non-tumour–related factors (including patient age, co-morbidity, and oncologists’ preferences) influence treatment patterns. Such practice is not consistent with current evidence and recommendations, all of which may affect outcomes of bladder cancer patients.
 
While substantial progress has ensued in the field of other genitourinary malignancies, bladder cancer research lags behind. Under-enrolment, lack of specific funding for bladder cancer, and lack of cooperative group trials are some of the problems that research needs to overcome. An inter-hospital cancer database could provide important information to clinicians and health care administrators so as to formulate health care plans. Relevant outcome data could benefit both urologists and patients, when it comes to improving bladder cancer treatment.23
 
There are several limitations to be noted regarding this study. First, the survey was a retrospective review of practice. Second, the reported numbers and percentages were estimations without any verification, which may have introduced inaccuracy and recall bias. Third, this was a hospital-based survey instead of being individual-based, with 11 government and eight private hospitals that provide urology services. It nevertheless covered common local practice in most of the hospitals and institutions, and should be representative. Fourth, currently there are about 100 board-certified practising urologists in Hong Kong, so surveying a larger number of urologists might have yielded a broader view of practice patterns at an individual level.
 
Conclusions
This study provided important information on practice preferences in the management of bladder cancer in both public hospitals and private institutions in Hong Kong. It demonstrated great diversity in the use of intravesical immunotherapy, perioperative systemic chemotherapy, and surgical treatment of bladder cancer in different urology centres. There is a need for clear local recommendations and guidelines in these areas.
 
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Type 2 diabetes management in Hong Kong ethnic minorities: what primary care physicians need to know

Hong Kong Med J 2014;20:222–8 | Number 3, June 2014 | Epub 30 Jan 2014
DOI: 10.12809/hkmj134035
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Type 2 diabetes management in Hong Kong ethnic minorities: what primary care physicians need to know
Catherine XR Chen, MRCP (UK), FHKAM (Family Medicine); KH Chan, FRACGP, FHKAM (Family Medicine)
Department of Family Medicine and GOPC, Queen Elizabeth Hospital, 30 Gascoigne Road, Kowloon, Hong Kong
 
Corresponding author: Dr Catherine XR Chen (uccxr758@ha.org.hk)
Abstract
Objectives: To identify the demographics and compare diabetes control in ethnic minority group diabetes patients with Chinese diabetes patients who are managed in primary care settings and to explore strategies to improve their care.
 
Design: Retrospective case series.
 
Setting: General Outpatient Clinic of a Hong Kong Hospital Authority hospital.
 
Patients: Chinese type 2 diabetes patients and ethnic minority groups who had been regularly followed up with annual assessments carried out between 1 March 2012 to 28 February 2013 were recruited. Their serum levels of fasting glucose, creatinine, estimated glomerular filtration rate, haemoglobin A1c levels, lipid profile, blood pressure, and co-morbidities were retrieved from the Clinical Management System. Student’s t test and analysis of variance were used to evaluate continuous variables and the Chi squared test for categorical data. All statistical tests were two-sided, and a P value of <0.05 was considered significant.
 
Results: Among 4346 type 2 diabetes patients fulfilling the inclusion criteria, 3966 (91.3%) patients were Chinese and 380 (8.7%) were from the ethnic minority groups. Compared with Chinese diabetes patients, the latter were much younger and more obese (both P<0.001). Their glycaemic control was poorer than age- and sex-matched Chinese diabetes patients (P=0.006). Control of systolic blood pressure was similar in the two groups, but the mean diastolic blood pressure was higher in the ethnic minority groups than in the controls (78 ± 11 mm Hg vs 73 ± 11 mm Hg; P<0.001). With regard to lipid control, their total cholesterol, low-density lipoprotein, and triglyceride levels were similar, but high-density lipoprotein levels were much lower in the ethnic minority groups than their Chinese counterparts (1.19 ± 0.33 mmol/L vs 1.28 ± 0.36 mmol/L; P=0.001). Among the five major ethnic minority groups with diabetes, Pakistani patients had particularly poor glycaemic control and the Nepalese had the poorest diastolic blood pressure control.
 
Conclusions: Ethnic minority groups are an integral part of the Hong Kong population. Compared with Chinese diabetes patients, those from the ethnic minorities were much younger and more obese. Deficiencies exist in the comprehensive management of diabetes in these ethnic minorities, particularly with respect to glycaemic control. Culturally tailored health care interventions are therefore warranted to promote patient education and clinical effectiveness and to improve their long-term health status.
 
 
New knowledge added by this study
  • Compared with Chinese diabetes patients, ethnic minority group (EMG) diabetes patients from South Asia were much younger but more obese and had higher co-morbidity from hypertension.
  • In EMG diabetes patients, glycaemic control was poorer than their age- and sex-matched Chinese counterparts (mean ± standard deviation, haemoglobin A1c 7.8 ± 1.7% vs 7.5 ± 1.4%; P=0.006). Systolic blood pressure control was similar in the two groups, but the mean diastolic blood pressure was higher in EMG cohort (78 ± 11 vs 73 ± 11 mm Hg; P<0.001). High-density lipoprotein levels were much lower in EMG diabetes patients than in the Chinese controls (1.19 ± 0.33 vs 1.28 ± 0.36 mmol/L; P=0.001).
  • Among the five major EMGs of diabetes patients, Pakistani patients had particularly poor glycaemic control and the Nepalese had the poorest diastolic blood pressure control.
Implications for clinical practice or policy
  • Deficiencies exist in the comprehensive management of diabetes among South Asian diabetes patients in Hong Kong. Genetic factors, obesity, insulin resistance, and poor compliance to medical advice and treatment due to multiple socio-economic factors have been postulated to contribute to this occurrence.
  • Local doctors should pay particular attention to their requirements and offer flexible and integrated care that reflects their physical, psychological, social, and cultural needs.
 
Introduction
Type 2 diabetes mellitus (T2DM) is one of the most common chronic conditions encountered in primary care, and affects up to 10% of Hong Kong (HK) population.1 Its complications include kidney disease, blindness, lower limb amputation, and coronary heart disease; all of which lead to increased morbidity and mortality.2
 
Ethnic minorities constitute an important component of the HK population. According to census in 2011, about 95% of the local inhabitants are ethnic Chinese; the remainder (ethnic minorities) are mainly from Asia (India, Philippines, Nepal, Pakistan, and Indonesia).3 Previous studies have shown that diabetes affects certain ethnic minority groups (EMGs) differently.4 South Asians are at higher risk for T2DM by up to 4 to 6 fold compared with other ethnic groups, probably due to a combination of genetic and environmental factors.5 6 In addition, South Asians have a much higher prevalence of T2DM with cardiovascular disease that occurs at an earlier age and is associated with higher morbidity and mortality.7 Differences in health care systems, limited access to health services, and social deprivation can further compound the risk of developing diabetes and its complications.
 
Improving the quality of chronic disease management is an essential component of health policy in the community. Locally, a significant proportion of T2DM patients including those from EMGs are managed in primary care and followed up at government general out-patient clinics (GOPCs) of the Hong Kong Hospital Authority (HKHA). The clinic where the authors work is one of the largest GOPCs of the HKHA, and more than 50% of its attendees have chronic diseases including diabetes. In addition, it is located in central Kowloon, where most of the South Asian minorities including Indians, Nepalese, and Pakistanis reside.
 
Till now, local data on the diabetic control among EMG diabetes patients are lacking. To address this knowledge gap, we aimed to identify and compare the demographics of diabetes and its control in ethnic minority and Chinese patients managed in primary care and to explore possible strategies to improve care. We believe this study will provide important background information to address important issues pertinent to chronic disease management within various HK ethnic groups.
 
Methods
This was a retrospective case series study carried out in the Yau Ma Tei Jockey Club GOPC of the HKHA. According to a pilot study carried out in early 2012, the five major ethnic minorities undergoing regular follow-up in this clinic were from India, Nepal, the Philippines, Pakistan, and Indonesia. Regular follow-up was defined as returning to our clinic for chronic disease management on a regular basis, ie, every 1 to 4 months. Very few Caucasians or other Asian ethnic groups such as the Japanese and Koreans had regular follow-up at this clinic and were therefore excluded from the analysis.
 
Subjects
Patients with T2DM coded by International Classification of Primary Care (ICPC) T90, who had been regularly followed up at Yau Ma Tei Jockey Club Clinic between 1 March 2012 and 28 February 2013 and had an annual blood and urine checkup at least once during this period, were recruited. The diagnosis of diabetes was based on the “Definition and description of diabetes mellitus” from American Diabetes Association in 2010.8 Wrongly diagnosed diabetes patients, type 1 diabetes patients, diabetes patients who were regularly followed up in the specialist out-patient departments (SOPDs), diabetes patients who had no annual checkup within this period, and those who were neither Chinese nor belonged to the above five EMGs were excluded.
 
Determination of variables
The recruited patients’ age, gender, ethnicity, smoking status, body mass index (BMI), latest blood pressure, fasting blood sugar (FBS), haemoglobin A1c (HbA1c) and creatinine levels, urine albumin/creatinine ratio, and lipid profile were retrieved from the Clinical Management System (CMS) of the HKHA. The most recent blood and urine test was used for analysis if more than one test had been performed during the study period. The BMI was calculated as body weight/body height2(kg/m2).The patient was considered a smoker if he/she currently smoked or was in the first 6 months of stopping.
 
We used the abbreviated Modification of Diet in Renal Disease9 to give an estimated glomerular filtration rate (eGFR) expressed in mL/min/1.73 m2, and chronic kidney disease was defined as having an eGFR of <60 mL/min/1.73 m2:
eGFR=186 × [SCR/88.4]–1.154 × [age]–0.203 × [0.742 if female]
where SCR was the serum creatinine level expressed as µmol/L
 
The medical history of stroke, ischaemic heart disease (IHD), and concomitant hypertension (HT) were retrieved based on ICPC codes in the CMS. Stroke cases were retrieved using ICPC codes K89 (transient ischaemic attack), K90 (cerebrovascular accident), and K91 (cerebrovascular disease). Cases of HT were retrieved using ICPC codes K86 (uncomplicated HT) and K87 (complicated HT). Patients with IHD were retrieved using the codes K74 (IHD with angina), K75 (acute myocardial infarction), and K76 (IHD without angina). Repeat systolic blood pressures (SBPs) of ≥130 mm Hg or diastolic blood pressures (DBPs) of ≥80 mm Hg confirmed a diagnosis of HT in diabetes patients.10
 
Statistical analyses
All data were entered and analysed using computer software (Statistical Package for the Social Sciences; Windows version 16.0; SPSS Inc, Chicago [IL], US). Student’s t test and analysis of variance were used to analyse continuous variables and Chi squared tests for categorical data. Tukey and Games-Howell tests were used for pairwise comparisons within the five minority groups, if applicable. All statistical tests were two-sided, and a P value of <0.05 was considered significant.
 
Results
A list of 5536 T2DM patients followed up in this clinic from 1 March 2012 to 28 February 2013 was generated from the CMS. Among them, 1190 (21.5%) were excluded due to the already described exclusion criteria (11 wrongly diagnosed as diabetic, 1 had type 1 diabetes, 395 were regularly followed up in the SOPDs, 2 were Caucasians, and 781 diabetes patients had no blood and urine check-up during the recruitment period). Thus, findings from the remaining 4346 (78.5%) patients fulfilling our inclusion criteria were analysed. Among these patients, 3966 (91.3%) were Chinese and 380 (8.7%) were from the EMGs. Table 1 summarises the demographic characteristics of these patients in both the Chinese and EMGs. In summary, they were comparable in terms of gender ratio and smoking status (both P>0.05). However, patients from the EMGs were significantly younger (mean ± standard deviation [SD], 55.4 ± 11.7 years vs 66.1 ± 11.5 years; P<0.001) and their BMIs were much higher (mean ± SD, 28.5 ± 4.6 kg/m2 vs 25.8 ± 4.3 kg/m2; P<0.001) than those of the Chinese diabetes patients.
 

Table 1. Demographic characteristics of diabetes patients recruited into study*
 
To reduce confounding due to age, 380 age- and sex-matched diabetes patients were randomly selected from the Chinese diabetes cohort. Table 2 summarises the glycaemic, blood pressure and lipid profile control, as well as kidney function in these diabetic Chinese and EMGs. The latter patients were found to have a greater proportion with HT than the Chinese diabetic controls (P=0.03), whereas their co-morbidity rates for stroke, IHD, and chronic kidney disease were similar. Glycaemic control was poorer in EMG diabetes patients than their age- and sex-matched Chinese counterparts (HbA1c, 7.8 ± 1.7% vs 7.5 ± 1.4%; P=0.006). Consistently, their FBS levels were also much higher than those of the controls (P=0.02). With regard to blood pressure control, SBP was similar in the two groups, but the mean DBP was higher in the EMG cohort (78 ± 11 vs 73 ± 11 mm Hg; P<0.001). When lipid control was compared, total cholesterol, low-density lipoprotein (LDL), and triglyceride levels were found to be similar in the two groups. High-density lipoprotein levels (HDLs), however, were much lower in the EMG diabetes patients (1.19 ± 0.33 mmol/L vs 1.28 ± 0.36 mmol/L; P=0.001).
 

Table 2. Metabolic, blood pressure and lipid profile control, and renal function in Chinese and ethnic minority group diabetes patients matched with age and sex*
 
Regarding the demographic characteristics of EMG diabetes patients (Table 3), most were Nepalese (n=169), followed by Indian (n=103), Filipino (n=51), Pakistani (n=47), and Indonesian (n=10). The male-to-female (M/F) ratio was much higher in the Pakistani, Indian, and Nepalese groups (P<0.001). However, the mean age of the Nepalese and Pakistani patients was much younger than that of the Indian and Indonesian groups (P=0.004). More Nepalese and Pakistani diabetes patients were chronic smokers than those from the other ethnic minorities (P<0.001).
 

Table 3. Demographic characteristics of diabetes patients in different ethnic minority groups*
 
Table 4 shows glycaemic, blood pressure, and lipid profile control in diabetes patients within the individual EMGs. Owing to their dissimilar age and gender composition, comparisons between different minority groups were inevitably confounded. Nevertheless, the data indicated that glycaemic control was particularly poor in Pakistani patients (mean ± SD HbA1c levels being 8.4 ± 1.6%), and less so in the Nepalese and Indian groups (7.8 ± 1.9% and 7.8 ± 1.7%, respectively). In contrast, the metabolic control of Indonesian diabetes patients was generally satisfactory (mean HbA1c level being 6.8 ± 0.6%). The mean SBP was similar among all EMGs, but the mean DBP control was suboptimal in the Nepalese group (84 ± 11 mm Hg) and within target in the other minority groups. When lipid control was studied, the total cholesterol, LDL, and triglyceride levels were similar, but Pakistani patients had a much lower mean HDL level (1.04 ± 0.27 mmol/L).
 

Table 4. Chronic disease control in ethnic minority group diabetes patients*
 
Discussion
This study was the first clinical analysis of T2DM patients in local EMGs. It compared demographic characteristics of both Chinese and EMG diabetes patients managed in primary care. Notably, it revealed discrepancies between the groups in terms of glycaemic, blood pressure, and lipid profile control.
 
Notably, in HK, the basic demographic features of Chinese diabetes patients and those from EMGs were quite different. The latter were younger and more obese; such findings were in line with those in the HK census in 2011 which showed that 61.3% of EMGs were aged 25 to 44 years and that the median age for all EMG patients was much lower than that of the entire HK population.3 In addition, the main reason for staying in HK for nearly all EMG subjects was to work, and when asked about their occupation most of the recruited EMG diabetes patients (n=334, or 87.9% of them) stated that they undertook manual labour. Thus, most were in their 40s and 50s and therefore their mean age was understandably younger than that of their Chinese counterparts (identified within a gradually ageing population). Furthermore, diabetes patients from South Asian ethnicities were more obese and had a much higher BMI than their Chinese controls. It is well known that the prevalence of obesity varies substantially between ethnic groups and is estimated to differ according to the precise measurements used (eg BMI, waist-to-hip ratio, and waist circumference). Although no data in the literature have directly compared the BMI of Chinese diabetes patients with that of those from South Asia, studies from UK have revealed that the mean waist-hip girth ratios and trunk skin folds were larger in South Asians than in European and Chinese groups.11
 
Since age is a very important confounder that prevented direct comparison between the two groups, age- and sex-matched diabetes patients from the Chinese and ethnic minorities were studied further. Even so, glycaemic control was poorer in EMG patients than the matched Chinese controls (mean ± SD, HbA1c 7.8 ± 1.7% vs 7.5 ± 1.4%; P=0.006). Whereas SBP control was similar, the mean DBP was higher in the EMGs (P<0.001). In addition, the mean HDL levels were much lower in EMGs than in the matched Chinese controls (P=0.001). Possible reasons for such a difference between could be multi-factorial. First, several studies have shown that genetic factors may play a determinant role.12 13 Diabetes patients from the South Asia appear more likely to have insulin resistance and a higher prevalence of obesity and metabolic syndrome, all of which are chronic conditions that challenge glucose metabolism.5 Second, patients from EMGs are often at a socio-economic disadvantage and difficult to reach via mainstream channels, and so they face inequalities in accessing medical care.3 For example, EMG diabetes patients might not have their diabetes diagnosed if they were socially disadvantaged and might be less inclined to seek medical care. Moreover, underdiagnosed individuals may be more likely to have poor diabetic control and experience early mortality. Third, the first language of South Asian groups is usually neither English nor Chinese, and therefore they may not understand the medical advice properly. Lastly, their cultures, religious beliefs, and lifestyles may influence their behaviour (including levels of physical activity and food choices), all of which affect health status and management. Coordinated efforts are therefore needed to overcome these limitations and embark on integrated diabetes monitoring and surveillance programmes in such EMGs.
 
We also need to be aware that a large proportion of diabetes patients followed up at public GOPCs are from lower-income groups and the geriatric populations. Younger Chinese T2DM patients might be more inclined to seek help from Specialist Clinics and private doctors. Thus, these findings might not be directly applicable to private or other specialist settings. Nevertheless, the present findings suggest important groundwork for further local and international studies.
 
The demographic characteristics of diabetes patients within EMGs indicated that their gender ratios also varied dramatically. Among Filipino patients, the M/F ratio was 0.31 and all Indonesian patients were female. By contrast, most Pakistani, Indian, and Nepalese diabetes patients were male (M/F ratios being 2.62, 1.51, and 1.35, respectively). These findings were consistent with a thematic report on ethnic minorities in the 2011 HK population consensus, which showed considerable variations in the gender composition of different ethnic groups in the community3; the M/F ratios of Indonesians and Filipinos were extremely low but the ratios were converse among Pakistanis and Nepalese. This was because large proportions of Filipinos and Indonesians in HK were foreign domestic helpers, of whom 99% were female.3 On the contrary, most Nepalese and Pakistanis worked in elementary occupations such as at construction sites or as security guards, and most were males. This difference in gender composition also contributed to a greater proportion of Nepalese and Pakistanis being chronic smokers as compared with the other Asian minorities. As the different age and sex distributions among EMGs was an important confounder of clinical outcomes, no direct comparison on diabetes control between different subgroups was feasible. Nevertheless, we found that Pakistani diabetes patients had particularly higher HbA1c levels and lower HDL concentrations. Indeed, studies have shown that the epidemiology and determinants of diabetes in Pakistan reveal a peculiar combination of risk factors.13 Strong genetic and environment factors interplay along with in-utero programming, in the context of low birth weights and gestational diabetes contributing to a high prevalence and poor control of T2DM in Pakistanis.14 On the other hand, Nepalese diabetes patients had suboptimal DBP control. This finding is in line with World Health Organization reports that Nepal has a high burden of HT and that the blood pressure control rates have been poor due to the inadequate awareness and lack of proper treatment.15 16 Local doctors should therefore pay particular attention to the needs of different ethnic groups and offer a flexible care package that reflects their physical, psychological, social, and cultural needs and at the same time upholds their autonomy, dignity, privacy, and personal choice.
 
Diabetes is a significant problem among both the Chinese and EMGs in HK. It is important that government officials, clinicians, and allied health workers understand the evidence and implement strategies to address shortcomings actively. Our local practice has emphasised empowering people with diabetes to support their own care management by proper diet control and active lifestyle strategies. In addition, concerted efforts are needed to raise awareness of diabetes and disseminate prevention messages to high-risk groups in collaboration with their community opinion leaders. Nowadays, information, interpretation, and advocacy services have been provided in HKHA clinics, which is definitely a positive step towards improving understanding of the disease among ethnic minority patients. Meanwhile, our services should assimilate aspects of ethnicity and culture, and implement culturally specific interventions to improve diabetes control in HK EMGs.
 
Implications to the primary care
Family physicians are at the forefront of T2DM management, and aim to achieve optimal metabolic control to prevent macro- and micro-vascular complications. This study provides important background information on the demographic characteristics of diabetes patients from certain EMGs as compared to Chinese diabetes patients. Since certain South Asian groups tend to have poorer glycaemic control, culturally tailored health care interventions are required to improve their general health and chronic disease management.
 
Study limitations
One limitation was that only diabetes patients who were regularly followed up in a single clinic and had annual blood and urine checkups were studied. Second, the ethnic composition in other clinics and elsewhere in HK might differ considerably. Third, patients who were followed up at this clinic but never attended for annual assessment (n=781, 14.1%), whatever the reason, were excluded and must have given rise to a selection bias. However, we have compared the major epidemiological characteristics including age and gender of such patients and found that there were no obvious differences between them and the studied patients (P=0.45 and P=0.60, respectively). Fourth, all variables were measured at least once during the 1-year study period, and if more than one blood test was performed, the most recent result was used for analysis. Therefore, variability of measurements might have confounded the findings. Fifth, the relatively small sample size of certain EMG subgroups and their age and gender distribution discrepancies prevented direct comparison of their metabolic control. Nevertheless, the present results may lay the groundwork for similar studies in the future both locally and internationally. Lastly, concomitant chronic diseases (HT, IHD, and stroke) were retrieved via the ICPC code in the CMS, and so inadequate ICPC coding may have underestimated co-morbidity rates in both Chinese and EMG diabetes patients.
 
Conclusions
Ethnic minority groups are an integral part of the HK population. Compared with Chinese diabetes patients, EMG diabetes patients were much younger and more obese. Deficiencies existed in their understanding of diabetes management, particularly glycaemic control. Culturally tailored health care interventions are therefore necessary to promote patient education and clinical effectiveness for these patient groups and improve their long-term health.
 
Acknowledgements
We extend our gratitude to Dr King Chan for his continuous inspiration and support during this study. We also thank Ms Elise Chan, EA III of Department of Family Medicine and GOPC, for her patience during data entry and Mr Carl Chak, statistical officer of Queen Elisabeth Hospital, for his expertise and support in data analysis.
 
References
1. Chan JC, Malik V, Jia W, et al. Diabetes in Asia: epidemiology, risk factors, and pathophysiology. JAMA 2009;301:2129-40. CrossRef
2. Leung GM, Lam KS. Diabetic complications and their implications on health care in Asia. Hong Kong Med J 2000;6:61-8.
3. Hong Kong 2011 population census thematic report: ethnic minorities. Available from: http://www.statistics.gov.hk/pub/B11200622012XXXXB0100.pdf. Accessed Dec 2012.
4. Abate N, Chandalia M. The impact of ethnicity on type 2 diabetes. J Diabetes Complications 2003;17:39-58. CrossRef
5. McKeigue PM, Shah B, Marmot MG. Relation of central obesity and insulin resistance with high diabetes prevalence and cardiovascular risk in South Asians. Lancet 1991;337:382-6. CrossRef
6. Khan NA, Wang H, Anand S, et al. Ethnicity and sex affect diabetes incidence and outcomes. Diabetes Care 2011;34:96-101. CrossRef
7. Gholap N, Davies M, Patel K, Sattar N, Khunti K. Type 2 diabetes and cardiovascular disease in South Asians. Prim Care Diabetes 2011;5:45-56. CrossRef
8. American Diabetes Association. Diagnosis and classification of diabetes mellitus. Diabetes Care 2010;33(Suppl 1):S62-9. CrossRef
9. Levey AS, Bosch JP, Lewis JB, Greene T, Rogers N, Roth D. A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Modification of Diet in Renal Disease Study Group. Ann Intern Med 1999;130:461-70. CrossRef
10. Chobanian AV, Bakris GL, Black HR, et al. Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Hypertension 2003;42:1206-52. CrossRef
11. Gatineau M, Mathrani S. Obesity and ethnicity. Available from: http://www.noo.org.uk/uploads/doc/vid_9444_Obesity_and_ethnicity_270111.pdf. Accessed Jan 2011.
12. Gupta M, Singh N, Verma S. South Asians and cardiovascular risk: what clinicians should know. Circulation 2006;113:e924-9. CrossRef
13. Rees SD, Britten AC, Bellary S, et al. The promoter polymorphism -232C/G of the PCK1 gene is associated with type 2 diabetes in a UK-resident South Asian population. BMC Med Genet 2009;10:83. CrossRef
14. Samad S, Fatima J, Asma M. Prevalence of diabetes in Pakistan. Diabetes Res Clin Pract 2007;76:219-22. CrossRef
15. WHO STEPS Surveillance: Non Communicable Disease Risk Factors Survey. Kathmandu: Ministry of Health and Population, Government of Nepal, Society for Local Integrated Development Nepal (SOLID Nepal) and WHO; 2008.
16. Sharma D, Bkc M, Rajbhandari S, et al. Study of prevalence, awareness, and control of hypertension in a suburban area of Kathmandu, Nepal. Indian Heart J 2006;58:34-7.

Social obstetrics: non-local expectant mothers admitted through accident and emergency department in a public hospital in Hong Kong

Hong Kong Med J 2014;20:213–21 | Number 3, June 2014 | Epub 9 May 2014
DOI: 10.12809/hkmj134181
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Social obstetrics: non-local expectant mothers admitted through accident and emergency department in a public hospital in Hong Kong
WK Yung, MB, BS, FHKAM (Obstetrics and Gynaecology)1; Winnie Hui, MB, BS1; YT Chan, MB, BS, MRCOG1; TK Lo, FHKAM (Obstetrics and Gynaecology)1; SM Tai, BSc, MSc1; C Sing, BSc, MSc1; YY Lam, MB, BS, FHKAM (Paediatrics)2; CM Lo, FRCP (Irel), FHKAM (Emergency Medicine)3; WL Lau, MB, BS, FRCOG1; WC Leung, MD, FHKAM (Obstetrics and Gynaecology)1
1 Department of Obstetrics and Gynaecology, Kwong Wah Hospital, 25 Waterloo Road, Hong Kong
2 Department of Paediatrics, Kwong Wah Hospital, 25 Waterloo Road, Hong Kong
3 Department of Accident and Emergency, Kwong Wah Hospital, 25 Waterloo Road, Hong Kong
 
Corresponding author: Dr WC Leung (leungwc@ha.org.hk)
Abstract
Objectives: To review the pregnancy outcomes of non-booked, non-local pregnant women delivering in Kwong Wah Hospital via admission to the Accident and Emergency Department 1 year after the announcement by the Hospital Authority to stop antenatal booking for non-eligible persons; and to perform a literature review of local studies about non-eligible person deliveries over the last decade.
 
Design: Case series.
 
Setting: A public hospital in Hong Kong.
 
Participants: All women who held the People’s Republic of China passport or the two-way permit and those non-eligible persons whose spouses were Hong Kong Identity Card holders, who delivered in Kwong Wah Hospital from 1 April 2011 to 31 March 2012.
 
Results: Overall, 219 women who were non-eligible persons delivered 221 live births during the study period. Compared with the annual statistics of Kwong Wah Hospital in 2011, non-local mothers were of higher parity; more likely to have hypertensive disease (including pre-eclamptic toxaemia), preterm deliveries (ie at <37 weeks), babies needing admission to the special care baby unit, and macrosomic babies (ie weighing >4.0 kg). The rates of induction of labour and caesarean section were lower in this group. There was no significant difference in the maternal and neonatal outcomes between women who had no booking and those who had a booking in another Hospital Authority or private hospital. There were many incidents of near-miss obstetric complications or suboptimally managed obstetric conditions due to lack of well-structured and continuous antenatal care in this group of non-eligible persons.
 
Conclusion: Non-eligible person delivering babies in Hong Kong has become a social obstetrics phenomenon. Despite the introduction of policies, reduction in the number of deliveries (quantity) did not improve the obstetric outcomes (quality). Health care professionals should continue to be prepared for managing the potential near-miss clinical complications in this group of ‘travelling mothers’.
 
 
New knowledge added by this study
  • Non-eligible person (NEP) delivery in Hong Kong has been a social obstetric phenomenon specific to this region (Hong Kong SAR) because of political circumstances. Despite the reduction in the quantity, these non-booked deliveries continue to run a high risk of adverse obstetric outcomes due to difficulties experienced by the expectant mothers in accessing a well-structured obstetric service.
Implications for clinical practice or policy
  • Regardless of the number of patient load, the NEP women remain potentially at risk of obstetric complications. Health care professionals should be prepared for managing the near-miss conditions.
 
Introduction
The influx of expectant mothers from Mainland China leading to overwhelming of the local obstetric and neonatal services has been a hot topic of discussion in the media in the past few years. In 2001, the Hong Kong Court of Final Appeal delivered a unanimous opinion by which Chong Fung-yuen, a Chinese baby born while his Mainland Chinese parents were in Hong Kong on two-way permits, was granted residency in Hong Kong. In addition, in 2003, the Hong Kong SAR Government introduced the Individual Visit Scheme which allowed travellers from Mainland China to visit Hong Kong and Macao on an individual basis. Since the introduction of these policies, there has been a dramatic increase in the number of ‘traveller’ mothers delivering in Hong Kong. This ‘birth tourism’—a travel to a country that practises birthright citizenship or permanent residency in order to give birth there, so that the child will be a citizen of the destination country—has significantly influenced the standard obstetric practice in Hong Kong, resulting in adverse pregnancy outcomes. We have described this phenomenon as social obstetrics.1 2 3
 
According to the Hospital Authority (HA) pay code, there are seven categories of non-eligible person (NEP). The categories of NE-2 (People’s Republic of China passport or two-way permit holder ‘雙非’) and NE-3 (NEP whose spouse is a Hong Kong Identity Card [HKID] holder ‘單非’) contribute to the majority of NEP deliveries in public hospitals.
 
In 2005, the HA launched an obstetric package to limit the number of non-local women delivering in public hospitals. The charge was HK$20 000 for 3 days and 2 nights of hospital stay including delivery. However, this policy did not discourage ‘traveller’ mothers from delivering in public hospitals.4
 
In February 2007, the HA launched a new obstetric package for non-local expecting mothers. This package charged almost double (HK$39 000) for the hospitalisation for 3 days and 2 nights. Those who have not booked were additionally charged.
 
Unfortunately, the growing number of NEP deliveries in HA hospitals outweighed the capacity of public obstetric and neonatal services. In 2010, there were about 88 000 deliveries in the territory, of which 50% were by mainland mothers (Fig 1a). The total capacity of neonatal intensive care units (NICUs; about 100 beds) in Hong Kong can only support an annual delivery rate of 75 000.5 This resulted in the formation of Hong Kong Obstetric Service Concern Group in March 2011—to urge the Hong Kong SAR Government to take action in preventing the collapse of public obstetric and neonatal services. The first remedial measure was to stop accepting new antenatal booking in HA hospitals from 8 April 2011 till the end of the year. One year later, on 26 April 2012, HA announced that there was no booking quota for non-local expecting mothers as public service was prioritised for the Hong Kong citizens to meet the surge of childbirth in the Chinese year of ‘Dragon’. The non-booked deliveries would be charged HK$90 000 for the 3-days-2-nights package. Lastly, the Government prohibited antenatal booking of non-local mothers in either public (for NE-2 and NE-3 categories) or private (for NE-2 category) sectors from 1 January 2013 onwards (Table 16 7).
 

Figure 1. (a) Number of non-eligible person (NEP) and total deliveries in Hong Kong (data from Hospital Authority). (b) Number of NEP deliveries in public hospitals via accident and emergency department (AED) and non-AED admissions (data from Hospital Authority)
 

Table 1. Milestones in non-eligible person deliveries in Hospital Authority Obstetric Units
 
However, if a pregnant woman, regardless of her identity card status, attended the accident and emergency department (AED) of a public hospital, the doctor-on-duty would assess her condition and offer admission to the obstetric unit if medically indicated. The admission rate via AED through the years varied with the implementation of obstetric package and government policy (Fig 1b). In 2005, when the first obstetric package was launched, the admission through AED for delivery was high. The second package in 2007 encouraged antenatal booking, and, thus, the AED admission rate dropped thereafter. Since April 2011, HA stopped all antenatal bookings for NEP, as a result of which the total number of NEP deliveries decreased drastically; however, the proportion of AED admissions increased.
 
In Kwong Wah Hospital, antenatal booking for non-local mothers had been stopped since April 2011. The NEP deliveries in our unit were mainly through AED admission or transfer from another HA or private hospital.
 
This retrospective study reviewed the pregnancy conditions and outcomes of a cohort of non-booked, non-local women admitted via AED of Kwong Wah Hospital over a 1-year period.
 
Methods
This study evaluated the demographics, peripartum events, and pregnancy outcomes of the non-local pregnant women (NE-2 and NE-3 categories) who were admitted through AED and who delivered in Kwong Wah Hospital from 1 April 2011 to 31 March 2012. This was the 1-year period after HA’s announcement (on 8 April 2011) of stopping antenatal booking for non-local women. The birth registry record of Kwong Wah Hospital was reviewed. Women who delivered in the captioned period with no HKID number were identified. Clinical records of the subjects were retrieved from the central record unit. Only women in NE-2 and NE-3 categories were recruited.
 
Clinical notes and electronic patient records of the subjects were reviewed. The pregnancy conditions studied included the presenting symptoms, antenatal complications, gestation at delivery, mode of delivery, intrapartum and postpartum complications, birth weight of babies, Apgar score, need for neonatal resuscitation, admission to NICU or special baby care unit, neonatal morbidities, congenital abnormalities, etc. Maternal and neonatal outcomes were further analysed according to their booking status before admission. The annual statistics of Kwong Wah Hospital 2011 were used as reference.
 
Statistical analysis
Skewed continuous variables and nearly normally distributed variables were presented as medians (interquartile ranges) and means (± standard deviations [SDs]), respectively. Categorical data were presented as counts and percentages. Mann-Whitney U test and independent sample t test were used for comparison of medians and means, respectively. Pearson Chi squared test or Fisher’s exact test were used for comparisons of frequencies, where appropriate. All analyses were performed with the Statistical Package for the Social Sciences (Windows version 16.0; SPSS Inc, Chicago [IL], US). A P value of less than 0.05 was regarded as statistically significant.
 
Ethics approval
Ethics approval for this study was granted by the Kowloon West Cluster Clinical Research Ethics Committee.
 
Results
A total of 219 maternities with delivery were identified during the study period. There were 221 live births (three pairs of twins) and one stillbirth. Two (0.9%) pregnancies had been achieved by assisted reproduction. The mean (± SD) age of women was 29.9 ± 5.6 years. Of the 219 women, 138 (63.0%) were multiparous, 28 (12.8%) of them had had one previous caesarean delivery, and one (0.5%) had had two previous Caesarean sections. Overall, 139 (63.5%) women were of NE-2 category and 53 (24.2%) were of NE-3 category; the remaining 27 (12.3%) did not provide information about their partners. A total of 138 (63.0%) women had no booking in Hong Kong; 61 (27.9%) women had antenatal booking in other HA hospitals; and 20 (9.1%) women were booked in private hospitals but were referred or chose to deliver in HA hospitals.
 
The reasons of admission were as follows: show or with irregular uterine contraction (n=98, 44.7%), suspected rupture of membranes (n=52, 23.7%), active phase of labour (n=40, 18.3%), and antenatal complications (n=21, 9.6%; these included 10 cases of antepartum haemorrhage, five cases of preterm prelabour rupture of membranes, three cases of concerns on fetal wellbeing, two cases of maternal pre-eclampsia, and one case of threatened preterm labour). Five women admitted for postdate pregnancy requested for delivery. Two pregnancies were delivered in an ambulance and one on arrival to AED. One pregnancy was a stillbirth diagnosed after admission.
 
Routine antenatal blood tests (complete blood picture, blood group and Rhesus factor, immune status for hepatitis, syphilis, rubella, and human immunodeficiency virus) were performed in 147 (67.1%) women. For the rest of the women, results of blood tests performed in another HA or private hospital were available via electronic or hard copies. Ultrasound assessment was performed for 126 (57.5%) women before delivery.
 
Of the 219 pregnancies, 23 (10.5%) were delivered before 37 weeks of gestation; two (0.9%) pregnancies were delivered after 42 weeks of gestation. A total of 141 (64.4%) women had spontaneous onset of labour; 32 (14.6%) needed induction of labour, and 22 (10.0%) needed augmentation of labour.
 
The majority of women (n=182; 83.1%) had normal vaginal deliveries. Three (1.4%) pregnancies required instrumental assistance. Caesarean section was performed in 13 (5.9%) pregnancies after labour and 21 (9.6%) without labour. The success rate of trial of vaginal delivery after one previous Caesarean section was 50%. There was no uterine scar rupture in any case. Primary postpartum haemorrhage occurred in 13 (5.9%) pregnancies. Seven (3.2%) women required blood transfusion. The mean length of postnatal hospital stay was 2.0 ± 0.4 days.
 
Peripartum maternal complications were divided into mild and significant. Mild complications included seven cases of gestational hypertension, two cases of mild pre-eclampsia without magnesium sulphate treatment, three cases of gestational diabetes on insulin treatment, three cases of moderate thrombocytopenia (platelet count 50-100 x 109 /L), five cases of retained placenta requiring surgical exploration, five cases of postpartum haemorrhage managed by medical therapy, three cases of post-delivery urinary retention, and five cases of postpartum fever. Significant complications included six cases of severe pre-eclampsia requiring magnesium sulphate treatment, two cases of placenta abruptio, two cases of major placenta praevia type IV, one case of massive primary postpartum haemorrhage requiring surgical intervention, and two cases of severe thrombocytopenia (platelet count <50 x 109 /L).
 
During the study period, there were 121 (54.8%) male and 100 (45.2%) female live births. The mean birth weight was 3.3 ± 0.5 kg. There were 19 (8.7%) babies with low birth weight (<2.5 kg); 13 (5.9%) were macrosomic (>4.0 kg). Two babies required neonatal resuscitation. The admission rates to the NICU and special care baby unit (SCBU) were 3.7% and 43.8%, respectively. Overall, 15 (6.8%) babies had minor congenital abnormalities. Three (1.4%) had major abnormalities, including one ventricular septal defect, one atrial septal defect, and one bilateral congenital cataract. Apart from congenital problems, 51 babies had neonatal jaundice requiring phototherapy, 22 had respiratory complications, 22 had infection episodes, five had electrolyte disturbance, three had birth trauma, three had congenital hypothyroidism, three had hypoglycaemia, one had hypothermia, one had polycythaemia, one had anaemia requiring blood transfusion, one had neonatal autoimmune thrombocytopenia requiring intravenous immunoglobulin treatment, and one had neurological complications. The composite neonatal morbidity rate was 39.8%.
 
The pregnancy outcomes of the study cohort were compared with the annual statistics (2011) of Kwong Wah Hospital, as shown in Table 2. Non-local mothers were of higher parity; more likely to have hypertensive disease (including pre-eclamptic toxaemia), preterm delivery (<37 weeks), babies requiring admission to SCBU, and macrosomic babies (>4.0 kg). The rate of induction of labour and caesarean section was lower in this group.
 
We also analysed the maternal and neonatal outcomes based on their antenatal booking before admission (ie no booking versus booking in other HA or private hospitals). We found that there was no significant difference in maternal and neonatal outcomes between the two groups. The results are shown in Table 3.
 

Table 2. Comparison of pregnancy outcomes between the non-booked, non-local women and the KWH annual statistics in 2011
 

Table 3. Maternal and neonatal outcomes of pregnancies based on antenatal booking before admission
 
Discussion
Standard obstetric practice is influenced by social behaviour such as ‘birth tourism’ resulting in adverse pregnancy outcomes; we have described this phenomenon as social obstetrics.1 2 3 Some women came because they wanted to evade the ‘one-child’ policy of Mainland China. This was reflected in our study which showed that 63% of the NEP mothers were multiparous versus 45% from the hospital annual statistics. The higher proportion of multiparity also explained the lower rate of labour induction and caesarean delivery in the study group. On the other hand, the significantly higher rates of preterm delivery, hypertensive disease, macrosomic babies, and SCBU admission suggest that the NEP mothers belonged to a high-risk group.
 
In this study cohort, 63.5% of women belonged to the NE-2 category. Their travelling permit only allowed a short period of stay. In principle, there could be shared care between Hong Kong and Mainland China; in reality, this form of shared care is often suboptimal because of the differences in clinical practice and culture between the two places. Some mothers could not make antenatal booking in Mainland China under the ‘one-child’ policy. Serious conditions may be detected for the first time during an emergency admission.8 This largely endangers the health of mothers and babies. We have chosen six typical cases for illustrating this issue (Table 49 10 11 12).
 

Table 4. Cases to illustrate social obstetrics phenomenon9 10 11 12
 
Over the years, two local studies have been published on the pregnancy outcomes of non-local expectant mothers delivering in public hospitals in Hong Kong.6 7 Yuk and Wong6 from Princess Margaret Hospital conducted a study between 2004 and 2006 when the HA launched the first obstetric package to the non-local women in 2005. During that period, around 35% of deliveries in Princess Margaret Hospital were attributed to non-local Chinese women. The proportion increased significantly from 27% in 2004 to 43% in 2006. Compared with local Chinese women, the NEPs were younger, of lower parity, and had fewer pre-existing medical problems. However, they had higher chances of unplanned vaginal breech deliveries, severe hypertensive disease in pregnancy, pre-eclampsia, delivering before arrival to hospital, and giving birth post-term (≥42 weeks). Neonatal complications including preterm birth, stillbirth, and neonatal death were also more frequent among the NEP women. In fact, the first obstetric package was proposed mainly to charge the NEPs for delivery service expenses; it did not cover the antenatal service. This resulted in many of them coming to the hospital only for giving birth. Many of them came at the ‘last-minute’ to reduce the length of hospital stay due to financial concerns. This created a heavy burden on the public obstetric services and increased the risk of adverse pregnancy outcomes.
 
The second obstetric package in 2007 encouraged the NEP mothers to receive proper antenatal checkup. Lam7 from Tuen Mun Hospital conducted a study from 2006 to 2008 investigating the impact of the package on public obstetric services and pregnancy outcomes. It was observed that the number of NEP deliveries decreased from 1868 to 1398 per year. The number of non-booked admissions through AED reduced. The rate of post-term pregnancies dropped from 3.2% to 1.8%. The reason for fewer deliveries was a shift of patients to private obstetric services after setting the quota and raising the cost. Nevertheless, this obstetric package did not improve the admission behaviour and pregnancy outcomes.
 
Thanks to our HA and the Hong Kong SAR Government’s policy of stopping NEP bookings altogether in HA Obstetric Units, the number of NEP deliveries during our study period (2011-2012) was significantly reduced and limited to non-booked cases admitted through AED (Fig 2). We observed that reduction in ‘quantity’ did not improve the ‘quality’ of care in this group of women. The admission pattern and pregnancy outcomes remained similar to those in previous local studies. We also observed that, although some women had prior ‘booking’ in other HA or private hospitals, their pregnancy outcomes were no better than the ‘no booking’ group (Table 3). One possible reason for this could be that their travelling permit hindered them from receiving the ‘standard’ antenatal care. It was difficult to measure the quality of the obstetric care received by the ‘booked group’ because of its heterogeneity. We have used case examples to illustrate how the common obstetric conditions could be ‘near-miss’ conditions or standard obstetric service could be compromised under this social obstetrics phenomenon. We foresee that the third obstetrics package introduced in 2012 is unlikely to make a significant improvement in pregnancy outcomes unless the NEP women attend a structured antenatal care like the local mothers do.
 

Figure 2. Number of non-eligible person (NEP) deliveries in Kwong Wah Hospital (data from Hospital Authority)
 
In our study, we compared the pregnancy outcomes of our NEP cohort admitted through A&E (n=219) with the general pregnant population from our annual statistics (n=5862). This might introduce a pre-selection bias. Our NEP cohort was also limited by its relatively small number. In the study by Yuk and Wong,6 the pregnancy outcomes of the NEP cohort (n=4657) were compared with those of the eligible-person cohort (n=8655) from 2004 to 2006. In the study by Lam,7 the pregnancy outcomes of two NEP cohorts (n=1868 in 2006/2007 vs n=1398 in 2007/2008) were compared.
 
Conclusion
Non-local expectant mothers delivering babies in Hong Kong has become a classic social obstetrics phenomenon. There is nothing wrong with these mothers who would like to have their children to be born in Hong Kong and become permanent residents of Hong Kong. Not long ago, Hong Kong mothers wanted to give birth in the US or Canada so that their children could become citizens of those countries. The problem in Hong Kong is the large volume of pregnancies which has exceeded our obstetric and neonatal capacities, thus affecting the health care of our local pregnant mothers and neonates. Although our Government now prohibits NEP bookings in both public (for NE-2 and NE-3 categories) and private (for NE-2 category) hospitals, non-local expectant mothers continue to admit themselves through AED for deliveries. Health care professionals should continue to be prepared for managing these potential near-miss clinical situations arising from this social obstetrics phenomenon. We hope this paper serves as one of the historical records in literature for this social obstetrics phenomenon in the recent obstetric history of Hong Kong.
 
References
1. Leung WC. Social obstetrics—non-local expectant mothers delivering babies in Hong Kong. The Hong Kong Medical Diary 2009;14:13-4.
2. Leung WC, Lau WL. Cross-border families: transgression and dialogue [in Chinese]. Hong Kong: Red Publishing; 2008: 55-9.
3. Leung WC. Social obstetrics (cross-border pregnant women) [in Chinese]. Chiu MC, editor. Children, medicine, law: a comparative study of Greater China. Hong Kong: Roundtable Publishing; 2012: 40-8.
4. Au Yeung SK. Impact of non-eligible person deliveries in obstetric service in Hong Kong. Hong Kong J Gynaecol Obstet Midwifery 2006;6:41-4.
5. Leung TY, Lao T. Influx of mainland expectant mothers: a blessing or a curse? Hong Kong J Gynaecol Obstet Midwifery 2009;11:9-10.
6. Yuk JY, Wong S. Obstetrical outcomes among non-local Chinese pregnant women in Hong Kong. Hong Kong J Gynaecol Obstet Midwifery 2009;9:9-15.
7. Lam KD. Is the new obstetrics package for non-local pregnant women making a change? Hong Kong J Gynaecol Obstet Midwifery 2010;10:62-8.
8. Kwan WY, So CH, Chan WP, Leung WC, Chow KM. Re-emergence of late presentations of fetal haemoglobin Bart's disease in Hong Kong. Hong Kong Med J 2011;17:434-40.
9. Lo TK, Yung WK, Lau WL, Law B, Lau S, Leung WC. Planned conservative management of placenta accreta—experience of a regional general hospital. J Matern Fetal Neonatal Med 2014;27:291-6. CrossRef
10. Yung C, Liu K, Lau WL, Lam H, Leung WC, Chin R. Two cases of postmaturity-related perinatal mortality in non-local expectant mothers. Hong Kong Med J 2007;13:231-3.
11. Yung WK, Liu AL, Lai SF, et al. A specialised twin pregnancy clinic in a public hospital. Hong Kong J Gynaecol Obstet Midwifery 2012;12:21-32.
12. Liu AL, Yung WK, Lai SF, et al. Factors influencing the mode of delivery and associated pregnancy outcomes for twins: a retrospective cohort study in a public hospital. Hong Kong Med J 2012;18:99-107.

Ibuprofen versus indomethacin treatment of patent ductus arteriosus: comparative effectiveness and complications

Hong Kong Med J 2014;20:205–12 | Number 3, June 2014 | Epub 30 Jan 2014
DOI: 10.12809/hkmj134080
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Ibuprofen versus indomethacin treatment of patent ductus arteriosus: comparative effectiveness and complications
NM Chan, MRCPCH, FHKAM (Paediatrics); CW Law, MB, BS, FHKAM (Paediatrics); KF Kwan, FHKAM (Paediatrics)
Department of Paediatrics, Queen Elizabeth Hospital, 30 Gascoigne Road, Kowloon, Hong Kong
 
Corresponding author: Dr NM Chan (cnm312@ha.org.hk)
Abstract
Objectives: To compare the effectiveness and complications of intravenous ibuprofen versus indomethacin treatment of patent ductus arteriosus in preterm infants.
 
Design: Retrospective case series.
 
Setting: A tertiary referral centre in Hong Kong.
 
Patients: A total of 95 infants who had received at least one course of indomethacin or ibuprofen for closure of patent ductus arteriosus from January 2008 to December 2011 were studied.
 
Main outcome measures: Following the total switch from indomethacin to ibuprofen in clinical use in April 2010, outcomes of infants receiving indomethacin and ibuprofen were compared. The primary outcomes including rates of failed medical closure and recourse to surgical ligation were compared. The secondary outcomes including rates of all-cause mortality, bronchopulmonary dysplasia, intestinal complications (necrotising enterocolitis, spontaneous intestinal perforation), change in urine output and serum creatinine, and progression of any intraventricular haemorrhage were also evaluated.
 
Results: The failure rate of medical treatment was similar in the indomethacin and ibuprofen groups, with 16 (31%) such infants in the indomethacin group and 14 (33%) in the ibuprofen group; for ibuprofen this yielded a relative risk of 1.06 (95% confidence interval, 0.66-1.67; P=0.852). The proportion of infants having surgical ligation was also similar. A higher rate of intestinal complications (necrotising enterocolitis or spontaneous intestinal perforation) was encountered in our ibuprofen group (P=0.043). No significant difference was observed in other secondary outcomes determined.
 
Conclusion: In our clinical practice, ibuprofen and indomethacin were shown to be equally effective for medical closure of patent ductus arteriosus in premature infants. With the higher rates of intestinal complications and similar effects on renal function in the ibuprofen group, we conclude that ibuprofen may not have fewer adverse effects than indomethacin.
 
 
New knowledge added by this study
  • Ibuprofen was shown to be as effective as indomethacin for the medical closure of patent ductus arteriosus in premature infants in clinical practice in Hong Kong.
  • Ibuprofen may not have fewer adverse effects than indomethacin, as it was associated with higher rates of intestinal complications and similar effects on renal function.
Implications for clinical practice or policy
  • Close monitoring for adverse effects is recommended in infants with patent ductus arteriosus treated with either indomethacin or ibuprofen.
 
Introduction
Patent ductus arteriosus (PDA) is a common problem in preterm infants. Its occurrence is associated with prematurity and respiratory distress syndrome (RDS).1 2 A persistent left to right shunt in preterm neonates may be associated with neonatal morbidities, including bronchopulmonary dysplasia (BPD), intraventricular haemorrhage (IVH), and necrotising enterocolitis (NEC).3
 
Pharmacological closure of PDAs with indomethacin was first described in 1970s.4 Reported complications associated with the use of indomethacin included renal impairment,5 NEC, spontaneous intestinal perforation,6 and impaired cerebral blood flow.7 Ibuprofen, another cyclo-oxygenase inhibitor, has been investigated as an alternative to indomethacin for the same purpose. Published randomised controlled trials reported that ibuprofen was as efficacious as indomethacin for PDA closure, and some studies claimed that it had fewer adverse effects and gave rise to less renal impairment than indomethacin.8 9 10 11
 
The use of ibuprofen for closure of PDA has been increasing in clinical practice worldwide. In Hong Kong, indomethacin has been replaced by ibuprofen since 2010 due to interruption of the supply of indomethacin from the pharmaceutical company. Local data on its effectiveness and safety in clinical practice are very limited. A study comparing the use of ibuprofen versus indomethacin for this purpose could provide valuable data for clinicians regarding their use in clinical practice. At our unit, intravenous indomethacin had been used for treatment of PDA in preterm infants until April 2010. After that date, ibuprofen was used due to cessation of the supply of indomethacin from the pharmaceutical company supplying our hospital. We therefore set out to compare the two infant cohorts for treatment effectiveness and complications when used in our local setting.
 
Methods
Patients and study design
This retrospective study was conducted in the neonatal intensive care unit (NICU) of Queen Elizabeth Hospital, a tertiary referral centre in Hong Kong with a level III neonatal intensive care service. The subjects in this study were all preterm infants admitted to the unit with their date of birth from 1 January 2008 to 31 December 2011 inclusive, and who had received at least one course of medical treatment for closure of a PDA with either indomethacin or ibuprofen. Due to the total switch from indomethacin to ibuprofen in clinical practice for this purpose in April 2010, we had information on two groups of infants—the indomethacin cohort (date of birth from 1 January 2008 to April 2010) and the ibuprofen cohort (date of birth from l April 2010 to 31 December 2011).
 
Preterm infants were defined as those who were born with less than 37 weeks of gestation. In our unit, preterm infants with clinical features suggestive of PDA, namely heart murmur, hypotension, hyperactive precordium, and increased ventilator settings were assessed by paediatric cardiologists. The diagnosis was then confirmed by echocardiography. Infants with a haemodynamically significant PDA were evaluated for medical closure with indomethacin/ibuprofen. Corresponding infants with features of heart failure, hypotension or who were ventilator-dependent were considered to have a haemodynamically significant PDA. Baseline assessments of these patients included platelet count, serum creatinine and electrolytes levels, urine output, and cranial ultrasound. Common contra-indications for the receipt of indomethacin/ibuprofen included thrombocytopenia, bleeding tendency, progressing IVH, NEC, and impaired renal function. Indomethacin was given at 0.1 mg/kg intravenously at 24-hour intervals for six doses or 0.2 mg/kg intravenously every 24 hours for three doses. Ibuprofen was given at 10 mg/kg, 5 mg/kg, and 5 mg/kg intravenously every 24 hours for a total of three doses. During the treatment courses, the infants were monitored for potential drug side-effects. Enteral feeding was withheld during the treatment course. Ductal closure was defined as persistent disappearance of the heart murmur; some of whom also had echocardiographic confirmation. Infants who failed the first course of medical treatment were re-evaluated and received a second course. Infants who failed two courses of medical treatment were considered for surgical ligation of the PDA in another tertiary referral centre in Hong Kong. Apart from the switch from indomethacin to ibuprofen in April 2010, the clinical practice for PDA management remained unchanged.
 
Data collection
Eligible infants were identified by the Clinical Data Analysis and Reporting System, and their medical records were retrieved for data extraction. The neonatal demographic variables and baseline characteristics of both groups were collected and compared. The effectiveness of the drugs was primarily measured by (1) the failure rate of PDA closure after medical treatment, and (2) rate of recourse to surgical ligation. Secondary outcomes included all-cause mortality before discharge, BPD, adverse effects on renal function, gastro-intestinal complications (NEC and spontaneous intestinal perforation), and IVH. Occurrence of BPD was defined as (1) the use of supplement oxygen at 28 days of life or (2) the use of supplement oxygen at 36 weeks’ postmenstrual age. Adverse effects on renal function were inferred by the magnitude of any serum creatinine and/or urine output change. Necrotising enterocolitis was diagnosed and classified according to modified Bell’s staging.12 Intraventricular haemorrhage was classified according to the standard grading system.13
 
Statistical analyses
The two groups of infants receiving indomethacin or ibuprofen were compared using independent sample t tests for continuous normally distributed data, while the Wilcoxon rank-sum test was used for continuous non-normal data. Chi squared and Fisher’s exact tests were used as appropriate for categorical variables. The relative risks (RRs) of the outcome measures between the two groups were determined. The extent of change in urine output and serum creatinine level during the treatment course (within-subject effect) and the difference in change between the two groups (between-subject effect) were analysed by repeated measures analysis of variance. Potential confounding factors for medical closure of the PDA,8 including gender, gestational age, RDS grading, PDA ductal diameter, and day of starting treatment were evaluated by logistic regression. Significant factors were then entered into a multivariate logistic regression model to determine adjusted odds ratios. In all the analyses, a P value of less than 0.05 was considered significant. The statistical analysis was performed using the Statistical Package for the Social Sciences (Windows version 16.0; SPSS Inc, Chicago [IL], US). The sample size estimation was based on the primary outcome measure: the difference in proportion of infants with medical closure between the two groups. The sample size calculation for a moderate effect size of 0.3, power of 80%, and an alpha of 0.05 indicated that around 40 subjects were needed in each group.
 
This study was approved by the Research Ethics Committee, Kowloon Central Cluster, Hospital Authority.
 
Results
Baseline characteristics
In all, 96 infants had medical treatment for closure of a PDA during the study period; 52 (55%) received indomethacin only and 43 (45%) received ibuprofen only. One infant, who received both indomethacin and ibuprofen during the transitional period, was excluded. There were no significant differences in the demographic variables and baseline characteristics of the two groups (Table 1), except for a higher proportion with severe IVH (grades 3 and 4) in the indomethacin group (P=0.01). There was no significant difference between these groups with respect to the number of infants receiving one or two courses of treatment (Table 1).
 

Table 1. Neonatal demographic variables and baseline characteristics*
 
Primary outcomes
Regarding the effectiveness of treatment, 20 (38%) of the infants in the indomethacin group and 18 (42%) in the ibuprofen group failed medical treatment after the first course; the RR of failure for the latter compared to indomethacin was 1.09, the 95% confidence interval (CI) being 0.69 to 1.69 (Table 2). Considering all courses of treatment with indomethacin or ibuprofen, 16 (31%) in the former group and 14 (33%) in the latter group failed medical treatment. Eleven (21%) infants in the indomethacin group and seven (16%) in the ibuprofen group underwent surgical ligation of the PDA. For the primary outcome measure, both groups were very comparable.
 
Factors with a potential to affect medical closure of PDA were evaluated. Among them, gestational age, RDS, and age at the start of medical treatment were shown to be significantly related to the rate of surgical ligation of PDA, with borderline significance for age at start of treatment in the univariate analysis (Table 3). When the above-mentioned significant factors were used in the multivariate analysis model, there was no significant difference between the two groups in terms of the rate of surgical ligation (adjusted odds ratio=0.94; 95% CI, 0.27-3.26; P=0.923).
 

Table 2. Effectiveness of treatment according to treatment group
 

Table 3. Factors associated with recourse to surgical ligation for patent ductus arteriosus by univariate and multivariate analyses
 
Secondary outcomes
Mortality
Within the study cohort, two (4%) infants in the indomethacin group and five (12%) in the ibuprofen group died before being discharged, but this yielded no statistically significant difference in all-cause mortality.
 
Respiratory outcomes
The rates of BPD were also similar in both groups (P=0.615 for use of supplement oxygen at 28 days and P=0.560 for use of supplement oxygen at 36 weeks’ postmenstrual age). The mean duration of invasive ventilation for the indomethacin group, however, was significantly longer than that for ibuprofen group (mean ± standard deviation, 35 ± 35 vs 20 ± 25 days; P=0.045), while the mean duration of oxygen dependency was similar (P=0.694; Table 4).
 

Table 4. Secondary outcomes according to treatment group*
 
Gastro-intestinal effects
Although not statistically significant, there was a higher rate of spontaneous intestinal perforation in the ibuprofen group (5% vs 0%, P=0.202), a higher rate of NEC (23% vs 12%, P=0.129), and NEC stage 2 or above (7% vs 2%, P=0.325) in the ibuprofen group (Table 4). On the other hand, on considering infants with NEC or spontaneous intestinal perforation together, there was a significantly higher rate in the ibuprofen than indomethacin group (P=0.043), and the same was true for gastro-intestinal bleeding (P=0.024).
 
Renal effects
Mean baseline serum creatinine concentrations and urine outputs were similar in the two groups (Table 1). Renal function related to the first course of treatment with indomethacin or ibuprofen was also studied. For within-subject effects, there were significant decreases in urine output (P<0.001) and increases in serum creatinine level (P=0.004) over time during treatment. For between-subjects effect, there was no significant difference in the changes of serum creatinine (P=0.829) and urine output (P=0.498) in the two groups, indicating that both drugs had a significant and comparable effect on renal function as measured by serum creatinine level and urine output (Fig).
 

Figure. (a) Urine output and (b) serum creatinine in the indomethacin and ibuprofen groups by day of treatment
 
Intraventricular haemorrhage
A larger proportion of infants in the indomethacin group had severe IVH at baseline. However, in both groups the rates of progression of IVH after treatment were similar (P=0.644).
 
Discussion
Our study compared the effectiveness and side-effects of intravenous indomethacin versus ibuprofen in treating PDA in preterm infants in two cohorts of Hong Kong patients. Our results demonstrate no significant difference in baseline characteristics between the two groups, thus justifying comparison of the cohorts. The two drugs appear to have similar effectiveness as measured by the rate of medical closure and surgical ligation rate of PDAs; such finding was also consistent with previous randomised controlled trials8 9 10 11and cohort studies.14 15 Even after potential confounding factors (discussed in the previous literature8) were controlled, the effectiveness of the two drugs did not differ significantly.
 
A higher all-cause mortality rate was observed in the ibuprofen group, although this did not reach statistical significance. The mortality case analysis was limited by the small number of deaths in each group; the power calculated was only 25%. Similar findings were reported by Katakam et al.15 When considering the individual cases, we observed that two infants in the ibuprofen group might have died of drug-related complications, namely spontaneous intestinal perforation and acute renal failure. Although one should not be biased by individual cases, these deaths illustrate the potential for fatal complications related to this drug.
 
We found no significant difference in the risk of BPD in the two groups; such result was consistent with that of a recent Cochrane review.16 By contrast another review by Jones et al17 concluded that intravenous ibuprofen may be associated with an increased risk of BPD when compared with intravenous indomethacin. These inconsistencies may be related to the definitions of BPD that were used. Our study considered BPD using the two most commonly used definitions (supplement oxygen use at 28 days and at 36 weeks' postmenstrual age, separately). Notably, similar rates of BPD were observed in the two groups for both definitions. By contrast, the duration of invasive ventilation was significantly longer in the indomethacin group. In this respect, a possible explanation and limitation of our study was that there may have been a gradual change in ventilation strategy over time, with a trend towards non-invasive ventilation.18
 
Regarding evaluation of possible gastrointestinal complications, two conditions (NEC and spontaneous intestinal perforation) have been described. Both are believed to be associated with impaired mesenteric blood flow due to a PDA as well as the use of cyclo-oxygenase inhibitors, though some recent studies have reported on the difference in clinical presentations and histological findings between these two entities.19 20 We observed a statistically higher rate of intestinal complications (NEC or spontaneous intestinal perforation) in the ibuprofen group (P=0.043). In contrast, the latest Cochrane review16 reported less NEC in the ibuprofen group (RR=0.68; 95% CI, 0.47-0.99). The management practice of preterm infants in our unit, including the feeding regimen, remained unchanged during the study period. Thus, this particular inconsistency could not be attributed to any known factors. Kushnir and Pinheiro14 studied 350 infants and also reported a higher rate of NEC in ibuprofen than indomethacin users (8% vs 4%; P=0.08). Rao et al19 studied 102 infants with PDA treated with ibuprofen, and reported a 9% rate of spontaneous intestinal perforation and 6% rate of NEC; such figures were comparable to those in our ibuprofen cohort. These findings suggest that compared with preterm infants treated with indomethacin, intestinal complications appear to be more common in those receiving ibuprofen.
 
We found that indomethacin and ibuprofen had a similar effect on renal function, though previous literature 8 9 15 16 17indicated that ibuprofen had less effect on renal blood flow and renal function. This inconsistency could be related to differences in how measurement of renal function was carried out. We evaluated the change in serum creatinine and urine output during the course of treatment. The change in these parameters, rather than the absolute values, might be better parameters to assess due to variations in serum creatinine with gestational age and the age of the infants.21 Another problem was the timing of measurements. Akima et al22 evaluated the renal effects of indomethacin and reported a significant increase in serum creatinine level on day 2 and day 7 of treatment when compared with the controls. Due to differences in the duration of treatment courses with the two drugs, the best time to carry out comparisons remains unclear. Moreover, as observed in one of our infants given ibuprofen who also developed acute renal failure 2 days after the completion of second course, there could be delayed and cumulative effects on renal function with repeat treatment courses. This was also shown by Kushnir and Pinheiro,14 whereby indomethacin had a more prominent effect on renal function during the first course while both drugs led to equal adversity at the second and third courses. However, the retrospective design of our study was a limitation as some data (especially on day 4 and later) in the ibuprofen group were influenced by the course lasting only 3 days, whilst data on the repeat courses of treatment were less complete. Hence, our study evaluated the first 4 days of the first course of treatment, and evaluation of repeat courses was excluded. With regard to the significant renal effects of ibuprofen and indomethacin noted in our study, we recommend close monitoring of renal function when either drug is used. Special cautions may be necessary for repeat courses of treatment.
 
Till now, published studies on the efficacy and safety of ibuprofen versus indomethacin were mainly randomised trials. The subjects in randomised trials were selected using inclusion and exclusion criteria that may be less representative of the whole spectrum of infants in clinical practice. For instance, randomised trials by Van Overmeire et al8 and Lago et al9 only studied infants with PDA treatment given in the first 2 to 4 days of life and RDS was an inclusion criterion. Our study included all infants that were treated within the study period, maximising the representativeness of the sample. Being a retrospective study to investigate the effectiveness and complications related to drug therapy in a clinical setting, the allocation of treatment was not randomised or blinded. However, selection bias was minimised as the drug treatment each infant received was only determined by the month and year they were admitted to the neonatal unit. On the other hand, being a study from two contiguous time periods, there may have been minor modifications of clinical practice despite that both infant cohorts being managed by the same group of clinicians and there being no change in departmental guidelines for management of PDAs.
 
Our study shared the limitations of most previous studies. Our sample size estimation was based on the primary outcome (the rate of successful medical closure). As the sample size was limited by the number of eligible infants within the study period, the effect size adopted in the sample size estimation was 0.3, which was moderate compared to other similar studies. Moreover, with respect to adverse outcome evaluation, infant numbers with positive findings were small, which affected the precision of our analyses. Another limitation was that two regimens of the indomethacin were used in our hospital: 0.1 mg/kg/dose every 24 hours for six doses (prolonged course) and 0.2 mg/kg/dose every 24 hours for three doses (short course). Fortunately, this heterogeneity within the group was small, as the majority of infants received the prolonged course (46 out of 52). Moreover, previous studies comparing these two regimens showed that their efficacy did not differ significantly.23 24 As for the generalisability of our study, variations in management of symptomatic PDA do exist between centres,25 26 and there is no consensus approach. Our practice, for trial of a second course of indomethacin or ibuprofen before considering surgical ligation, entailed intense monitoring for adverse effects, which was consistent with common practice.23 Thus, our study could provide useful information for other NICUs to consider for the management of PDA in preterm infants.
 
Conclusion
In clinical practice, intravenous ibuprofen is as effective as indomethacin for the medical closure of PDAs in premature infants. However, owing to the higher rates of intestinal complications after ibuprofen therapy, we conclude that it may not have fewer adverse effects than indomethacin. Neonatologists are therefore advised to cautiously monitor for possible side-effects in preterm infants receiving either indomethacin or ibuprofen for the treatment of PDAs.
 
Declaration
No conflicts of interests were declared by authors.
 
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