Discrete time modelling of disease incidence time series by using Markov chain Monte Carlo methods

Summary.  A stochastic discrete time version of the susceptible–infected–recovered model for infectious diseases is developed. Disease is transmitted within and between communities when infected and susceptible individuals interact. Markov chain Monte Carlo methods are used to make inference about these unobserved populations and the unknown parameters of interest. The algorithm is designed specifically for modelling time series of reported measles cases although it can be adapted for other infectious diseases with permanent immunity. The application to observed measles incidence series motivates extensions to incorporate age structure as well as spatial epidemic coupling between communities.     

上海市空气污染造成人群健康经济损失的研究

文章通过对上海市空气污染季节性状况的描述 ,分析了各种污染物的污染程度和变化趋势 ,并利用对上海某市级医院的实地调查数据 ,对空气污染物与医院呼吸系统疾病患者日门诊量之间的相关关系进行研讨 ,建立了多元分析模型 ,探讨了患者健康经济损失的计量方法 ,并对由空气污染造成呼吸系统疾病患者健康经济损失进行了估算。研究表明 ,在其他条件不变的情况下 ,NOX 日指数每增长 10 % ,被调查医院呼吸系统疾病患者的日门诊人次增加 7 7人次 ,而这些疾病患者由于患病产生的年度健康经济损失为 2 11万元。据此作保守的推断估计 ,上海市一年内因NOX 超标而发生的呼吸系统疾病门诊行为造成的健康经济损失可以达到 4 2亿元。同样 ,SO2 和TSP造成门诊患者的健康经济损失分别为 1 5亿元和 0 86亿元     

Analysis of Regional Scale Risk of Whirling Disease in Populations of Colorado and Rio Grande Cutthroat Trout Using a Bayesian Belief Network Model

Introduction and spread of the parasite Myxobolus cerebralis, the causative agent of whirling disease, has contributed to the collapse of wild trout populations throughout the intermountain west. Of concern is the risk the disease may have on conservation and recovery of native cutthroat trout. We employed a Bayesian belief network to assess probability of whirling disease in Colorado River and Rio Grande cutthroat trout (Oncorhynchus clarkii pleuriticus and Oncorhynchus clarkii virginalis, respectively) within their current ranges in the southwest United States. Available habitat (as defined by gradient and elevation) for intermediate oligochaete worm host, Tubifex tubifex, exerted the greatest influence on the likelihood of infection, yet prevalence of stream barriers also affected the risk outcome. Management areas that had the highest likelihood of infected Colorado River cutthroat trout were in the eastern portion of their range, although the probability of infection was highest for populations in the southern, San Juan subbasin. Rio Grande cutthroat trout had a relatively low likelihood of infection, with populations in the southernmost Pecos management area predicted to be at greatest risk. The Bayesian risk assessment model predicted the likelihood of whirling disease infection from its principal transmission vector, fish movement, and suggested that barriers may be effective in reducing risk of exposure to native trout populations. Data gaps, especially with regard to location of spawning, highlighted the importance in developing monitoring plans that support future risk assessments and adaptive management for subspecies of cutthroat trout.     

Statement of Withdrawal: Statistical analysis of an endemic disease from a capture–recapture experiment

There are a number of statistical techniques for analysing epidemic outbreaks. However, many diseases are endemic within populations and the analysis of such diseases are complicated by changing population demography. Motivated by the spread of cowpox among rodent populations, a combined mathematical model for population and disease dynamics is introduced. An MCMC algorithm is then constructed to make statistical inference for the model based on data being obtained from a capture–recapture experiment. The statistical analysis is used to identify the key elements in the spread of the cowpox virus.     

Risk Assessment for Hospital-Acquired Diseases: A Risk-Theory Approach

We introduce a new approach to hospital-acquired disease risk assessment from public health databases. In a spirit similar to actuarial risk theory, we define an adjustment coefficient that can quantify the risk associated with a hospital department, allowing comparisons of similar departments. The adjustment coefficient characterizes the tail of the distribution of the total patient length of stay in a department before the first disease event occurs. We show that this coefficient is the solution of a Lundberg-like equation, and we provide a nonparametric estimation procedure for this measure, based on a Cramér-Lundberg approximation for the tail of the distribution. Using simulations, we provide evidence of the robustness of the approximation to various individual risk models. In addition, we illustrate the relevance of this approach by evaluating the risk associated with a standard patient safety indicator in 20 hospitals of southeastern France.     

医疗保险对老年人身体机能健康和心理健康的影响及其机制研究

随着我国人口老龄化不断加剧,切实保障好老年人健康格外紧迫。基于此,文章采用中国健康与养老追踪调查数据从身体机能健康和心理健康两个维度实证考察了医疗保险对老年人健康的影响及其作用机制。研究发现,医疗保险能够显著提高老年人身体机能健康和心理健康。机制研究表明,医疗保险能够显著提高老年人医疗服务利用、降低老年人慢性病发生率进而影响到老年人健康。因此,进一步扩大老年人医疗保险覆盖面、提高医疗保障水平、促进医疗服务公平性和可及性,是我国人口老龄化不断加剧状况下保障老年人健康的重要途径。     

关于我国农民工职业病维权困境的思考——从“开胸验肺”事件谈起

农民工张海超为确诊个人患有尘肺病不惜冒生命危险“开胸验肺”,这一事件引发了社会对农民工职业病维权问题的关注。我国农民工职业病维权面临着工伤认定程序漫长和维权成本高等困境。究其原因主要是法律不健全,职业病鉴定机构监管的缺失以及社会保障缺失。若要化解农民工职业病维权困境,必须健全相关法律,完善工伤保险制度并加强政府主导作用,只有这样才可切实保障农民工职业病患者权益。     

ASSOCIATIONS BETWEEN AIR POLLUTION AND HOSPITAL VISITS FOR CARDIOVASCULAR DISEASES IN THE ELDERLY IN SYDNEY USING BAYESIAN STATISTICAL METHODS

Using generalized linear models (GLMs), Jalaludin  et al. (2006;  J. Exposure Analysis and Epidemiology   16 , 225–237) studied the association between the daily number of visits to emergency departments for cardiovascular disease by the elderly (65+) and five measures of ambient air pollution. Bayesian methods provide an alternative approach to classical time series modelling and are starting to be more widely used. This paper considers Bayesian methods using the dataset used by Jalaludin  et al.  (2006) , and compares the results from Bayesian methods with those obtained by Jalaludin  et al.  (2006) using GLM methods.     

Incorporating human sexuality content into a positive youth development framework: Implications for community prevention

As approaches to positive youth development (PYD) gain momentum, the issue of sexuality – a critical component of human development – is being subsumed by ideological debates. In the current political climate, sexuality education is often relegated to biological and/or values-based approaches, neglecting essential relational and collective aspects of sexuality. Through the explication of sexuality as an important component of youth's social ecology, this paper provides a conceptual link between the goals of the Sexuality Information and Education Council of the United States' (SIECUS) Guidelines for comprehensive sexuality education and those of PYD. We argue that sexuality, as a normative part of human development, culture, identity, and relationships, be approached from an asset-based perspective, rather than a deficit-based perspective. We propose a framework that illustrates how aspects of sexuality are embedded within PYD contexts, and demonstrates how a sexuality education program rooted in SIECUS guidelines can further PYD goals across community contexts.     

Mate Availability and Women's Sexual Experiences in China

Data from the 1999-2000 Chinese Health and Family Life Survey were merged with community-level data from the 1982, 1990, and 2000 Chinese censuses to examine the relationship between the local sex ratio (number of men per 100 women) and sexual outcomes among women (N = 1,369). Consistent with hypotheses derived from demographic-opportunity theory, multilevel logistic regression analyses showed that women are more likely to be sexually active, to have had premarital sexual intercourse, to have been forced to have sex, and to test positive for a sexually transmitted infection when there is a relative abundance of age-matched men in their local community. Education, birth cohort, and geographic location also emerged as significant predictors of women's sexual experiences.