Arul Earnest

User acceptability and feasibility of self-testing with HIV rapid tests

Objective:Because HIV rapid tests are considered for self-testing, this study aims to determine the user acceptability and feasibility of self-testing. Methods:A cross-sectional study was performed on 350 systematically sampled participants across 2 Singapore HIV testing centers using the Abbott Determine HIV 1/2 blood sample rapid test (Abbott Laboratories, Abbott Park, IL). Participants were surveyed on knowledge of and attitudes toward rapid testing. To determine interrater agreement between self-testing and trained personnel testing, participants performed self-testing with visual instructions, followed by trained personnel testing. Ability to identify test outcomes was determined through interpretation of sample test results. Results:Eighty-nine percent of participants preferred testing in private, but most indicated that confidential counseling by trained counselors was necessary. Almost 90% found the kit easy to use and instructions easy to understand. Nevertheless, 85% failed to perform all steps correctly, especially blood sampling, and 56% had invalid results because of incorrect test performance. Interrater agreement between results from self-testing and trained personnel testing had a κ value of 0.28. Twelve percent could not correctly determine results using sample tests, including 2% and 7% who read positive and negative samples, respectively, incorrectly. Conclusions:A substantial proportion could not perform self-testing or identify outcomes. Self-testing with the Determine HIV 1/2 kit in Singapore should be deferred.

Quality of care achievements of the Prostate Cancer Outcomes Registry-Victoria.

Objective: To analyse the performance of the quality of prostate cancer (CaP) care over a 5‐year period with reference to three quality indicators (QIs) reported by the Prostate Cancer Outcomes Registry–Victoria (PCOR‐Vic):u2028QI‐1: Alignment with the modified Prostate Cancer Research International Active Surveillance (PRIAS) protocol guideline;u2028QI‐2: Timeliness of CaP care for men with high risk and locally advanced disease;u2028QI‐3: Positive surgical margins (PSMs) for organ‐confined pathological T2 disease.

Timeliness of lung cancer care in Victoria: a retrospective cohort study.

Objective: To assess factors associated with second‐line delays in the management of patients diagnosed with lung cancer.

Sample size calculations for the design of cluster randomized trials: A summary of methodology.

Cluster randomized trial designs are growing in popularity in, for example, cardiovascular medicine research and other clinical areas and parallel statistical developments concerned with the design and analysis of these trials have been stimulated. Nevertheless, reviews suggest that design issues associated with cluster randomized trials are often poorly appreciated and there remain inadequacies in, for example, describing how the trial size is determined and the associated results are presented. In this paper, our aim is to provide pragmatic guidance for researchers on the methods of calculating sample sizes. We focus attention on designs with the primary purpose of comparing two interventions with respect to continuous, binary, ordered categorical, incidence rate and time-to-event outcome variables. Issues of aggregate and non-aggregate cluster trials, adjustment for variation in cluster size and the effect size are detailed. The problem of establishing the anticipated magnitude of between- and within-cluster variation to enable planning values of the intra-cluster correlation coefficient and the coefficient of variation are also described. Illustrative examples of calculations of trial sizes for each endpoint type are included.

Effects of Bariatric Surgery on Liver Function Tests in Patients with Nonalcoholic Fatty Liver Disease

ObjectivesNonalcoholic fatty liver disease (NAFLD) affects over 80% of obese patients and is fueled by the metabolic syndrome. Weight loss is strongly advocated as a central treatment for NAFLD and has been shown to induce histological improvement. We aimed to define the patterns of improvement in NAFLD with weight loss and determine target weight goals for NAFLD resolution.MethodsA prospective study of 84 morbidly obese patients with NAFLD undergoing bariatric surgery was conducted. Intraoperative liver biopsies were taken. Monthly follow-up, including blood tests and measurements, was performed. We monitored improvements in NAFLD by monthly alanine aminotransferase (ALT) and gamma glutamyltransferase (GGT) levels over 1xa0year.ResultsThere was rapid improvement in ALT, particularly in the first 6xa0months following surgery, with statistically significant reduction in ALT at 2xa0months (35 vs 27xa0IU/L, pxa0<xa00.001). In multivariate analysis, there were significantly increased odds of ALT normalization after a %TBWL of 10–15% (odds ratio 2.49, pxa0=xa00.005). The odds of resolution increased with increasing weight loss. Triglyceride levels (odds ratio 0.59, pxa0=xa00.021) and baseline NAFLD activity score (odds ratio 0.28, pxa0<xa00.001) were also significantly related to ALT normalization. Improvements in ALT occurred prior to metabolic improvement and well before traditional ideal weight goals were reached.ConclusionImprovements in NAFLD occurred rapidly after bariatric surgery and were closely related to weight loss and metabolic factors. A 10–15% reduction in body weight is an appropriate target to achieve substantial improvement in ALT levels.Trial registration number: Australian Clinical Trials Registry (ACTRN12610000049077).

Spatial Analysis of Ambulance Response Times Related to Prehospital Cardiac Arrests in the City-State of Singapore

Abstract Objectives. The main objective of this study was to establish the spatial variation in ambulance response times for out-of-hospital cardiac arrests (OHCAs) in the city-state of Singapore. The secondary objective involved studying the relationships between various covariates, such as traffic condition and time and day of collapse, and ambulance response times. Methods. The study design was observational and ecological in nature. Data on OHCAs were collected from a nationally representative database for the period October 2001 to October 2004. We used the conditional autoregressive (CAR) model to analyze the data. Within the Bayesian framework of analysis, we used a Weibull regression model that took into account spatial random effects. The regression model was used to study the independent effects of each covariate. Results. Our results showed that there was spatial heterogeneity in the ambulance response times in Singapore. Generally, areas in the far outskirts (suburbs), such as Boon Lay (in the west) and Sembawang (in the north), fared badly in terms of ambulance response times. This improved when adjusted for key covariates, including distance from the nearest fire station. Ambulance response time was also associated with better traffic conditions, weekend OHCAs, distance from the nearest fire station, and OHCAs occurring during nonpeak driving hours. For instance, the hazard ratio for good ambulance response time was 2.35 (95% credible interval [CI] 1.97–2.81) when traffic conditions were light and 1.72 (95% CI 1.51–1.97) when traffic conditions were moderate, as compared with heavy traffic. Conclusions. We found a clear spatial gradient for ambulance response times, with far-outlying areas’ exhibiting poorer response times. Our study highlights the utility of this novel approach, which may be helpful for planning emergency medical services and public emergency responses.

Composite Measures of Individual and Area-Level Socio-Economic Status Are Associated with Visual Impairment in Singapore

Purpose To investigate the independent relationship of individual- and area-level socio-economic status (SES) with the presence and severity of visual impairment (VI) in an Asian population. Methods Cross-sectional data from 9993 Chinese, Malay and Indian adults aged 40–80 years who participated in the Singapore Epidemiology of eye Diseases (2004–2011) in Singapore. Based on the presenting visual acuity (PVA) in the better-seeing eye, VI was categorized into normal vision (logMAR≤0.30), low vision (logMAR>0.30<1.00), and blindness (logMAR≥1.00). Any VI was defined as low vision/blindness in the PVA of better-seeing eye. Individual-level low-SES was defined as a composite of primary-level education, monthly income<2000 SGD and residing in 1 or 2-room public apartment. An area-level SES was assessed using a socio-economic disadvantage index (SEDI), created using 12 variables from the 2010 Singapore census. A high SEDI score indicates a relatively poor SES. Associations between SES measures and presence and severity of VI were examined using multi-level, mixed-effects logistic and multinomial regression models. Results The age-adjusted prevalence of any VI was 19.62% (low vision = 19%, blindness = 0.62%). Both individual- and area-level SES were positively associated with any VI and low vision after adjusting for confounders. The odds ratio (95% confidence interval) of any VI was 2.11(1.88–2.37) for low-SES and 1.07(1.02–1.13) per 1 standard deviation increase in SEDI. When stratified by unilateral/bilateral categories, while low SES showed significant associations with all categories, SEDI showed a significant association with bilateral low vision only. The association between low SES and any VI remained significant among all age, gender and ethnic sub-groups. Although a consistent positive association was observed between area-level SEDI and any VI, the associations were significant among participants aged 40–65 years and male. Conclusion In this community-based sample of Asian adults, both individual- and area-level SES were independently associated with the presence and severity of VI.

Effect of dietary advanced glycation end products on inflammation and cardiovascular risks in healthy overweight adults: a randomised crossover trial

Diets high in advanced glycation end products (AGEs) are thought to be detrimental to cardiovascular health. However, there remains uncertainty about the beneficial effect of a low AGE diet on cardiovascular risk factors and inflammatory markers in overweight individuals. We thus performed axa0randomised, double blind, crossover trial to determine whether consumption of low AGE diets reduce inflammation and cardiovascular risks in overweight and obese otherwise healthy adults. All participants (nu2009=u200920) consumed low and high AGE diets alternately for two weeks and separated by a four week washout period. Low AGE diets did not change systolic (pu2009=u20090.2) and diastolic blood pressure (pu2009=u20090.3), mean arterial pressure (pu2009=u20090.8) and pulse pressure (pu2009=u20090.2) compared to high AGE diets. Change in total cholesterol (pu2009=u20090.3), low-density lipoprotein (pu2009=u20090.7), high-densityxa0lipoprotein (pu2009=u20090.2), and triglycerides (pu2009=u20090.4) also did not differ and there was no difference in inflammatory markers: interleukin-6 (pu2009=u20090.6), monocyte chemoattractant protein-1 (pu2009=u20090.9), tumour necrosis factor α (pu2009=u20090.2), C-reactive protein (pu2009=u20090.6) and nuclear factor kappa beta (pu2009=u20090.2). These findings indicate that consumption of low AGE diets for two weeks did not improve the inflammatory and cardiovascular profiles of overweight and obese adults.

Weight loss after laparoscopic adjustable gastric band and resolution of the metabolic syndrome and its components

Background:Substantial weight loss in the setting of obesity has considerable metabolic benefits. Yet some studies have shown improvements in obesity-related metabolic comorbidities with more modest weight loss. By closely monitoring patients undergoing bariatric surgery, we aimed to determine the effects of weight loss on the metabolic syndrome and its components and determine the weight loss required for their resolution.Methods:We performed a prospective observational study of obese participants with metabolic syndrome (Adult Treatment Panel III criteria) who underwent laparoscopic adjustable gastric banding. Participants were assessed for all criteria of the metabolic syndrome monthly for the first 9 months, then 3-monthly until 24 months.Results:There were 89 participants with adequate longitudinal data. Baseline body mass index was 42.4±6.2u2009kgu2009m−2 with an average age was 48.2±10.7 years. There were 56 (63%) women. Resolution of the metabolic syndrome occurred in 60 of the 89 participants (67%) at 12 months and 60 of the 75 participants (80%) at 24 months. The mean weight loss when metabolic syndrome resolved was 10.9±7.7% total body weight loss (TBWL). The median weight loss at which prevalence of disease halved was 7.0% TBWL (17.5% excess weight loss (EWL)) for hypertriglyceridaemia; 11% TBWL (26.1–28% EWL) for high-density lipoprotein cholesterol and hyperglycaemia; 20% TBWL (59.5% EWL) for hypertension and 29% TBWL (73.3% EWL) for waist circumference. The odds ratio for resolution of the metabolic syndrome with 10–12.5% TBWL was 2.09 (P=0.025), with increasing probability of resolution with more substantial weight loss.Conclusions:In obese participants with metabolic syndrome, a weight loss target of 10–12.5% TBWL (25–30% EWL) is a reasonable initial goal associated with significant odds of having metabolic benefits. If minimal improvements are seen with this initial target, additional weight loss substantially increases the probability of resolution.

Derivation of indices of socioeconomic status for health services research in Asia.

Background Environmental contexts have been shown to predict health behaviours and outcomes either directly or via interaction with individual risk factors. In this paper, we created indexes of socioeconomic disadvantage (SEDI) and socioeconomic advantage (SAI) in Singapore to test the applicability of these concepts in an Asian context. These indices can be used for health service resource allocation, research and advocacy. Methods We used principal component analysis (PCA) to create SEDI and SAI using a structured and iterative process to identify and include influential variables in the final index. Data at the master plan geographical level was obtained from the most recent Singapore census 2010. Results The 3 areas with highest SEDI scores were Outram (120.1), followed by Rochor (111.0) and Downtown Core (110.4). The areas with highest SAI scores were Tanglin, River Valley and Newton. The SAI had 89.6% of variation explained by the final model, as compared to 67.1% for SEDI, and we recommend using both indices in any analysis. Conclusion These indices may prove useful for policy-makers to identify spatially varying risk factors, and in turn help identify geographically targeted intervention programs, which can be more cost effective to conduct.