published_or_final_version / Public Health / Master / Master of Public Health

Objective: To evaluate the effectiveness of exercises on fall prevention among community-dwelling elderly. Design: Systematic review of randomized controlled trials. Method: The literature search of articles was conducted through the electronic databases of PubMed, Medline and EMBASE and manual search, and was confined to articles in English language with full text and publications from 2002 to 2012. Randomized controlled trials with exercise as the only intervention which aimed at reducing falls in older people aged 60 or above in community i.e. community-dwelling elderly were included. The primary outcomes were number of fallers, fall rate, time to the first and subsequent falls. Data Extraction: A total of 145 articles were retrieved through the electronic data bases (137 articles) and manual search (8 articles) of which 10 were selected after applying the inclusion criteria. According to the checklist developed by National Institute for Health and Clinical Excellence (NICE) for randomized controlled trials, the overall methodological quality of the 10 studies was rated as good as they had fulfilled 79%-93% of the assessment criteria in the NICE checklist. Results: The studies involved a sample size of 3,138 at the median age of 69 to 83. All the subjects were ambulatory and able to mobilize independently. The duration of exercise interventions ranged from 1.5 months to 12 months at a total of 11-156 hours. Eight studies showed that exercises were effective in fall prevention whereas two studies found no evidence of such effectiveness. The effect of exercises on fall prevention was multifactorial including the duration, frequency and continuity of the exercise programs, the health status of the target population and the individuals’ adherence to the exercise programs. Shorter exercise programs and make-up class arrangement resulted in higher adherence rate. Tailor-made (based on the functional capabilities of the subjects) and progressive (gradual increase of the intensity and challenge of the exercises during the intervention period) nature of the exercise programs also enhanced their effectiveness on the elderly. For the studies in which exercise did not have any positive effect on fall prevention, the subjects were generally older (median age at 81) and frailer (with 3-7 frail attributes). Conclusions: This review suggests exercise may be an effective intervention for fall prevention among community-dwelling elderly. Different types of exercise including strengthening, balance, endurance and weight-bearing exercises as well as Tai Chi may prevent falls. The elderly’s age and health status must be taken into consideration when designing exercise intervention programs for the elderly. Further researches are recommended to determine the optimal type, intensity, frequency and duration of exercises in fall prevention. Observations from the studies provide insights for future researches, such as the fall prevention effect of group and home exercises, tailor-made and progressive exercise programs. In Hong Kong, no randomized controlled trial studies have been conducted to examine different intervention programs on fall prevention. To achieve generalizabilty of the studies in the review, further local researches, particularly well designed and powered randomized controlled trials have to be conducted to assess the effect of different kinds of exercise interventions on fall prevention among the community-dwelling elderly. / published_or_final_version / Public Health / Master / Master of Public Health

Introduction: Due to the high prevalence of smoking in China, exposure to second hand smoke (SHS) is a serious public health issue. However, school-aged children’s behavioral responses to SHS exposure and the associated factors are unclear. Aims: This study aims to (a) identify the sources and settings of SHS exposure among school-aged sick children and their mothers in Guangzhou, China; (b) describe the behavioral responses of those children and mothers when exposed to SHS; and (c) examine the personal and environmental factors associated with children’s responses to SHS exposure. Methods: Qualitative and quantitative methods were combined in this study. Forty-five in-depth individual interviews were conducted to investigate sick school-aged children and their mothers’ understanding of and responses to SHS. A pilot survey was used to assess the validity and reliability of the questionnaire and the feasibility of the study. A cross-sectional survey was conducted with the children and their mothers at three hospitals in Guangzhou in 2012. All sick children who were aged 6 to 12 years, able to communicate in Mandarin Chinese, and not acutely or severely ill, along with their nonsmoking mothers, were invited to join this study. Results: A total of 339 pairs of sick children and their mothers were included in the data analysis. Of these pairs, 169 (49.9%) lived with smokers. All sick children and their mothers experienced high-level SHS and third hand smoke (THS) exposure inside or outside the home. Those living with nonsmokers were also at risk of household SHS and THS exposure from guests. Most of the sick school-aged children were unaware of the dangers of SHS and THS, while the mothers had a better understanding of SHS and THS. The majority of children would adopt self-protective behaviors when exposed to SHS. The regression model for children’s behavioral responses to SHS exposure by family smokers found two significant factors: amount of social support and family smoke-free policy. Five factors were associated with children’s behavioral responses to SHS exposure by guest smokers, including boys, living with smokers, amount of social support, family members informed of the dangers of smoking, and fathers protecting children from SHS. The amount of social support, and fathers protecting children from SHS were also associated with children’s behavioral responses to SHS exposure by stranger smokers. Conclusions: To our knowledge, this is the first study to describe self-protective behavioral responses to SHS exposure among sick school-aged children in mainland China and the personal and environmental factors associated with these responses. Boys, living with smokers, and a partial smoke-free policy at home were negatively related to children’s responses to SHS exposure; however, more information about smoking, fathers’ protection from SHS, and information about the harms of smoking by family members were associated with greater self-protection among sick school-aged children. Therefore, multiple-direction interventions should be considered for children’s health promotion about smoking and SHS. / published_or_final_version / Nursing Studies / Master / Master of Philosophy

Background Smoking prevalence is the highest in people with mental illness. As more and more countries develop governmental regulations to protect employees from exposure to environmental tobacco smoke, complete smoking bans or partial smoking bans have been introduced in many psychiatric hospitals. Objectives To systematically review the literature to examine the impact of smoking bans in psychiatric hospitals, to identify the obstacles to implement tobacco-free policy and provide recommendations for policy-making in Mainland China on implementing tobacco-free policy in psychiatric hospitals. Methods Multiple searches for key words were conducted through electronic sources including PubMed, Medline, PsycINFO, Cochrane Library, Google Scholar, and CNKI database for all relevant English language and Chinese language articles. The PICO (patient problem or population, intervention, comparison and outcomes) indicators were used as basic inclusion/exclusion criteria, data extraction and quality assessment. Results A total of 227 studies were identified (188 English language articles including 4 reviews and 39 Chinese language articles), and 25 articles (19 English articles and 5 Chinese articles) were included in this paper. For the English language studies, psychiatric inpatients generally had positive attitudes towards the tobacco-free policy in psychiatric hospitals and increasing number of inpatients wanted to quit smoking after hospitalized in a tobacco-free psychiatric hospital. Increasing number of staff members working in psychiatric hospitals were supportive of the tobacco-free policy compared to previous reviews. No change in patients’ aggressive behaviors after implementing smoking bans in the psychiatric hospitals was observed in most studies. Factors identified for successful implementation of tobacco-free policy in psychiatric hospitals included comprehensive planning time, good leadership and significant attitudinal and system changes, high level and consistency of staff support and cohesive teamwork, extensive training for staff and effective use of nicotine replacement therapy (NRT). For the Chinese language studies, negative outcomes of psychiatric inpatients were observed after a total smoking ban in one psychiatric hospital, but positive effects were observed when only the smoking amount was controlled in four psychiatric hospitals. Conclusions The tobacco-free policy aims at eliminating tobacco smoking for both staff members and patients in psychiatric hospitals so as to create a healthy place for work and stay. This goal can be achieved with the efforts of the hospitals and staff, and the cooperation of patients. National legislation to ban smoking in all hospitals, indoor and outdoor, are urgently needed in China Mainland. / published_or_final_version / Public Health / Master / Master of Public Health

This study aimed to (1) review the reported levels of fluoride in drinking waters, food stuffs and other environmental media around the world, and the current magnitude of prevalence of fluorosis observed in human being and animals, with special reference to India and (2) critically evaluate the strategy adopted for prevention and control of the fluorosis problem in India by conducting questionnaire surveys with professionals from 11 endemic districts, and high school students of two schools located at an endemic area with high fluorosis incidences. Through a comprehensive literature review, it was able to identify 18 endemic states in India with high fluoride levels in their drinking waters while having various degrees of fluorosis problems. These states were further classified into three categories, namely high (>10 mg/L fluoride in drinking waters), moderate (5-9.9 mg/L) and low (1-4.9 mg/L) endemic regions. There were five, nine and four states falling into the high, moderate and low endemic categories, respectively. High fluoride concentrations were observed in the soil near industrial sites, foodstuffs and beverages, and tea leaves. Also, adverse effects of fluoride on terrestrial and aquatic plants, terrestrial vertebrates and invertebrates, and aquatic vertebrates and invertebrates, were observed and demonstrated in laboratory conditions. The questionnaire survey with Indian professionals in 11 fluoride endemic districts found that although all districts had received funds for combating fluorosis problems, there had been delays in executing the associated health promotion, monitoring and treatment programmes in some districts and the utilisation of the fund for the programmes was quite slow. Staff appointment, staff training, medical treatment provision, education and awareness activities, referral hospital facility provision, vehicle facility, monthly reporting, clinical survey and water and urine samples testing, timely monitoring and supervision, and involvement of various medical staff, were found to be inadequate in most districts. In the questionnaire survey conducted at the two high schools, one of the schools (school A) was supplied with alternate source of filtered water (i.e., with normal fluoride concentration) and the second school (school B) was one, which had non-defluoridated ground water supply for drinking (i.e., with high fluoride concentration). This survey found that the awareness about signs of fluorosis, field visit of health worker, cause and preventability of fluorosis, and perception of spread of fluorosis, was comparatively better amongst students of school A than that of school B. Both the schools’ students had positive attitude towards cooperation, prevention and control efforts being made for fluorosis. / published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

Background: Air pollution is a serious concern all over the world, and there have been numerous studies showing its adverse effects on health outcomes including disease-specific hospitalization and mortality. Most of these studies were conducted in Western settings and focused on NO2, SO2, PM10 and black smoke; limited results on PM2.5 in Asia have been published. Objectives: This study attempted to identify association between PM2.5 concentration and daily mortality due to all-natural causes, cardiovascular diseases, and respiratory diseases in Hong Kong, a tropical city in Asia from 2008 to 2011. Methods: The study used a case-crossover study design with time-stratified referent selection strategy. The referents were selected on the same day of the week of the same month and year as the event day. In this way, biases due to autocorrelation, time trend, and seasonal pattern were controlled for by study design. Covariates including temperature, humidity, and gaseous pollutants (NO2, SO2, O3 and CO) were adjusted for by statistical modelling. The statistical method applied was Conditional Logistic Regression. Sensitive analyses using matched by month strategy were also conducted to check the robustness of the main analyses. The health outcome variables included were mortality due to all natural causes, cardiovascular disease, and respiratory disease. Each model was examined for effects of PM2.5 at each lag 0 through lag 5 day and, for the current and lag 1 day moving average (lag 0-1). Effects were measured in Excess Risks (ER) associated with 10 μg/m^3 increase in PM2.5. Results: Significant associations with PM2.5 were observed for mortality from all natural causes and cardiovascular disease at lag 0, lag 1, and lag 0-1; and from respiratory disease only at lag 1. At lag 0-1, PM2.5 was associated with mortality from all natural causes, cardiovascular disease, and respiratory disease with the ER (95% confidence interval) of 0.74% (95% CI: 0.29, 1.19), 1.4% (95% CI: 0.52, 2.27), and 0.67% (95% CI: -0.30, 1.64), respectively. After adjusting for each of the co-pollutants in two-pollutant model, the effect magnitude dropped except that one adjusting for CO. The ERs of mortality in co-pollutant models from all natural causes ranged from 0.23% to 1.72%, from cardiovascular disease ranged from 1.00% to 2.93%, and from respiratory disease ranged from -0.10% to 1.83%. The results were robust in sensitivity analyses. Conclusion: My study provides some information to support formulation of air quality control strategies and policies, and for updating air quality standards. Such information includes the overall and seasonal patterns of air pollutants and mortality in Hong Kong, as well as the excess risks of mortality associated with increase in PM2.5. Studies with individual data stratified for subgroups can be conducted in the future to investigate effect modification of lifestyle factors for the individuals and population. / published_or_final_version / Public Health / Master / Master of Public Health

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Proponents of marriage, both politicians and scholars, emphasize that marriage benefits health and empirical evidence supports the view that the married are healthier than the unmarried. While a significant body of work establishes the link between marital status and health, previous studies do not consider historical trends in this association. The main objective of the present study is to describe whether and how the association between marital status and health has changed over the past three decades in the United States. Given longstanding observations about gender and race differences in family and health processes, the second objective is to consider gender and race variation in marital status/health trends. Third, I consider whether those health trends by marital status can be attributed to change in family income--which is often viewed as an explanatory mechanism between marriage and health. Results based on three decades’ national health survey data show that over the span of the past three decades, the self-rated health of the never-married became more similar to that of the married; in contrast, over this same time span, the self-rated health of the widowed, divorced, and separated worsened over time, relative to the married. Analyses of two additional health measures (i.e. activity limitation and mortality) show that differences in both activity limitation status and general mortality between the married and each of the unmarried groups--including the widowed, divorced, separated and never married--have widened over recent decades. For each measure of health status, I find important gender and race variation in those health trends by marital status and challenge some long-held assumptions about gender, marital status, and health. Moreover, I find little evidence that family income explains those health trends by marital status. Potential explanations and implications of those trends in health and marital status are discussed. / text

The main research questions examined in this thesis concern the extent to which social class influence individuals' health, and how and whether individuals' occupation, education and lifestyles mediate between class and health. The conclusions drawn from the analysis of these empirical questions cast further light on the widening health inequalities seen in developed societies in recent decades. In particular, this research suggests that, employment conditions as well as educational levels are variables that need to be taken into account when planning policies aimed at tackling differences in health outcomes. Lifestyle variables, on the other hand, would appear to be almost irrelevant when explaining why the members of the more privileged social classes not only live longer than those in other classes, but also enjoy significantly better health over the course of their lives. In trying to understand the association between class and health, I define a theoretical framework that specifies the mechanisms through which class is linked to health. Social structure influences health by distributing certain factors such as material resources or some health-related behaviour that ultimately result in individuals having different living conditions. Educational attainment also affects the way these resources are employed and, therefore, lifestyles. A fundamental element of a social class is occupation: individuals' employment and working conditions also affect their health. Furthermore, the nature of a social structure has an effect on health at the aggregate level of analysis since social policies are partly the result of the structure of class interests. Four mechanisms are specified in order to systematically test this theoretical framework. Mechanisms (2) and (3), those that relate class and health through education and lifestyle lie at the heart of the empirical analysis. This analysis employs individual-level data drawn from health surveys carried out during the first half of the 1990s in the two countries selected for the analysis, United Kingdom and Spain. These countries are treated as contexts in which to test the theoretical explanation. The main results of the analysis reveal the importance of social class in determining health outcomes. Indeed, individuals from different classes enjoy distinct degrees of health. Specifically, individuals in the most privileged class categories have persistently better health than those in the other class categories. Differences exist in terms of both objective and subjective or self-perceived health. Moving on from observation to explanation, the analysis suggests that the distribution of certain resources across classes accounts for some of the variance in health outcomes. Hence, education is identified as a significant variable to comprehend part of the health inequalities in developed societies. Lifestyle, on the other hand, does not appear relevant in accounting for health outcomes. The small differences found between the United Kingdom and Spain in the mechanisms that link class and health suggest that the process through which class affects health is essentially similar in developed societies.

M. Tech. Environmental Health / The purpose of the study was to determine the knowledge and perception of the Environmental Health Practitioner regarding enforcing environmental health legislation and the procedures which must be followed in terms of building control. The objectives of the study were: to determine the knowledge of the Environmental Health Practitioner regarding enforcing environmental health legislation on building plans; to determine the perceptions of the Environmental Health Practitioner towards their roles and responsibility to enforce environmental health legislation through building control; to determine the perceptions of the Environmental Health Practitioner regarding the working relationship between environmental health and building control; and to compare the practical application when building plans are scrutinised by Environmental Health Practitioner with the legal requirements needed to prevent environmental health hazards.