Economic and environmental factors in Hong Kong suicides

We study the geographical suicide pattern in Hong Kong and examine the influence of socio-economic status on suicides. The geographical distributions of suicide at different age categories (youth, middle-aged, and elderly) varied albeit those of the youth and middle-aged seemed more alike. High population density would lead to more youth and middle-aged suicides while a high proportion of Cantonese speaking residents and low proportion of owner-occupiers would lead to more middle-aged suicides. Four etiological factors of suicides - financial status, environmental setting, self-independence, and homemakers (mainly housewives) - were identified. Strong financial status and self-independence with less homemakers would decrease suicide rates at all age categories. Poor environmental factors would however increase suicide in the youth and middle-aged categories.postprin

Study of family violence poly-victimization in China: design and preliminary findings

Session G4 - Panel 47: Family Violence Poly-Victimization in ChinaThe population survey adopts a combined approach in using school and household-based approaches. The school-based approach is more appropriate to gather information from children aged 15 – 17 to estimate the prevalence of child victimization experienced by them. The household-based approach, with both children aged 15 – 17 and parents with children aged below 18 were interviewed, is adopted. The household approach is the only viable option for interviewing parents and to collect information on child victimization experienced by children under age 15. The primary objective of this approach is to collect data to better estimate of prevalence rates of CSA and child victimization experienced by children under age 15, and to test a comprehensive profile of individual and family risk factors correlating to CSA and child victimization. From the school survey, a cohort of about 13,000 secondary students aged 15-17 will be interviewed in schools. From the household survey, a cohort of about 5,000 parents or guardians of children aged 0 – 17 and about 2,000 young persons aged 15 – 17 drawn from large representative samples from households in Hong Kong and 5 Mainland provinces will be interviewed face-to-face by trained interviewers. Data collection will be completed in June, 2010. Prevalence rates of IPV, elder abuse, in-law violence and child poly-victimization will be presented.postprin

Brief education to increase uptake of influenza vaccine among pregnant women: a study protocol for a randomized controlled trial

published_or_final_versionpublished_or_final_versio

Anxiety, but not depression, mediates stress and somatic symptoms in Chinese

Posters: abstract no. 2980Conference Theme: Stretching the Boundaries: From Mechanisms of Disease to Models of Healthpublished_or_final_versio

Factors associated with breastfeeding duration and exclusivity in mothers returning to paid employment postpartum

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Modelling variation of lower leg length growth in early life

We consider the estimation of sources of variation for panel data with repeated measurements. With no repeated measurements and known measurement error, models for variation decomposition have been proposed when there are one or more types of measurements. Estimation was performed using the EM algorithm accompanied by model augmentation that demands more computational efforts. In this article we extend previous variation models and modify the estimation methods in order to estimate various variation components after eliminating the unknown effects of measurement error. Specifically, methods that dispense with model augmentation and estimation of time-dependent covariates are considered. A set of lower leg length data from Chinese infants is analysed by using the proposed model. Interestingly, our results are consistent with the well-accepted three-phase (infancy-childhood-puberty) growth transition proposition for human growth. Moreover, gender effect is found to be time-varying. Copyright © 2001 John Wiley & Sons, Ltd.postprin

Estimating the effect of multiple imputation on incomplete longitudinal data with application to a randomized clinical study

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Cost-effectiveness simulation and analysis of colorectal cancer screening in Hong Kong Chinese population: comparison amongst colonoscopy, guaiac and immunologic fecal occult blood testing

Background: The aim of this study was to evaluate the cost-effectiveness of CRC screening strategies from the healthcare service provider perspective based on Chinese population. Methods: A Markov model was constructed to compare the cost-effectiveness of recommended screening strategies including annual/biennial guaiac fecal occult blood testing (G-FOBT), annual/biennial immunologic FOBT (I-FOBT), and colonoscopy every 10 years in Chinese aged 50 year over a 25-year period. External validity of model was tested against data retrieved from published randomized controlled trials of G-FOBT. Recourse use data collected from Chinese subjects among staging of colorectal neoplasm were combined with published unit cost data ($USD in 2009 price values) to estimate a stage-specific cost per patient. Quality-adjusted life-years (QALYs) were quantified based on the stage duration and SF-6D preference-based value of each stage. The cost-effectiveness outcome was the incremental cost-effectiveness ratio (ICER) represented by costs per life-years (LY) and costs per QALYs gained. Results: In base-case scenario, the non-dominated strategies were annual and biennial I-FOBT. Compared with no screening, the ICER presented$20,542/LYs and $3155/QALYs gained for annual I-FOBT, and$19,838/LYs gained and $2976/QALYs gained for biennial I-FOBT. The optimal screening strategy was annual I-FOBT that attained the highest ICER at the threshold of$50,000 per LYs or QALYs gained. Conclusion: The Markov model informed the health policymakers that I-FOBT every year may be the most effective and cost-effective CRC screening strategy among recommended screening strategies, depending on the willingness-to-pay of mass screening for Chinese population. Trial registration: ClinicalTrials.gov Identifier NCT02038283published_or_final_versio

Dynamic Random Effects Models for Times between Repeated Events

We consider recurrent event data when the duration or gap times between successive event occurrences are of intrinsic interest. Subject heterogeneity not attributed to observed covariates is usually handled by random effects which result in an exchangeable correlation structure for the gap times of a subject. Recently, efforts have been put into relaxing this restriction to allow non-exchangeable correlation. Here we consider dynamic models where random effects can vary stochastically over the gap times. We extend the traditional Gaussian variance components models and evaluate a previously proposed proportional hazards model through a simulation study and some examples. Besides, semiparametric estimation of the proportional hazards models is considered. Both models are easily used. The Gaussian models are easily interpreted in terms of the variance structure. On the other hand, the proportional hazards models would be more appropriate in the context of survival analysis, particularly in the interpretation of the regression parameters. They can be sensitive to the choice of model for random effects but not to the choice of the baseline hazard function.postprin

The effect of health-related quality of life (HRQOL) on health service utilisation of a Chinese population

This study was designed to find out whether health-related quality of life (HRQOL) was an independent determinant of health service utilisation of a Chinese population and to determine whether the addition of HRQOL data to sociodemographic and morbidity factors could significantly increase the explanatory power of risk-adjustment models. A cross-sectional random telephone survey of the general adult Chinese population in Hong Kong was conducted among 2410 Chinese aged 18-88yr old, 52% were females and 38% had one or more chronic diseases. Health service utilisation was measured by annual consultation, monthly consultation and hospitalisation rates. HRQOL was measured by the SF-36. Multivariate regressions were used to test the dependence of service utilisation rates on sociodemographic factors, chronic morbidity and the SF-36 scores. Structured multiphase regression analyses were used to determine the magnitude of the effect of the SF-36 scores, in addition to those of sociodemographic and chronic morbidity factors, on service utilisation. Five of eight SF-36 scores were independent determinants of consultation rates. They doubled and tripled the percentages of variance explained for annual and monthly consultation rates, respectively. Role limitation by physical problems and bodily pain scores had a significant effect on hospitalisation rates. This was the first study showing a linear relationship between HRQOL and service utilisation on a Chinese population. It confirmed the clinical relevance of the SF-36 to a culture and health care system that is different from that of the United States where the instrument originated. © 2002 Elsevier Science Ltd. All rights reserved.postprin