Effectiveness of participatory training on improving occupational health in small and medium enterprises in China.

BACKGROUND: Participatory training on occupational health is widely used in the world. Evaluations of local experiences are necessary to its successful performance. OBJECTIVES: The project evaluated the effectiveness of participatory training on occupational health improvement in small and medium enterprises of China, and explored local practice experiences. METHODS: Participatory training was provided to 525 welding workers from 25 small and medium enterprises in ship building and machinery manufacturing industries. This training consisted of interactive learning, worksite assessment and group discussion on laws/regulations, safety of machine operation, prevention of slips and trips, fire/explosion prevention, ergonomics, and recognition and prevention of other workplace hazards. Workers completed knowledge, attitude, and practice and worksite assessment questionnaires before and 3 months after intervention. RESULTS: Knowledge, attitude, and practice scores were significantly increased through the training. An inventory of workplace safety modifications was proposed by participants and many were fixed by workers and employers. Health management and personal protective equipment provision/use were most often improved, but improvements in engineering control and health-related accommodations remained unsatisfactory. CONCLUSIONS: Workers could recognize and fix workplace hazards after the participatory training. More efficient measures in China are to be explored to improve implementing solutions, especially on preventive engineering and human ergonomics.

Environmental tobacco smoke exposure and Chinese schoolchildren's respiratory health: a prospective cohort study.

BACKGROUND: Although China is the most coveted cigarette market worldwide, few studies have examined the longitudinal effects of environmental tobacco smoke (ETS) on health. PURPOSE: To examine the relationship between exposure to ETS and respiratory health in Chinese schoolchildren. METHODS: The study subjects included 1718 children, who were never-smokers, aged 10.05±0.86 years and asthma-free at baseline. The children performed spirometric tests in 2006 and 18 months later. Parents reported the children's respiratory symptoms and illnesses, ETS exposure, and other related information by self-administered survey at both assessment points. The data were analyzed in 2010. RESULTS: Significant exposure-response relationships were found between ETS exposure and coughing at night (p for trend<0.001); sneezing (p for trend=0.031); and sneezing with itchy, watery eyes (p for trend=0.006) in the first survey, and coughing at night (p for trend=0.019); phlegm without a cold (p for trend<0.001); and sneezing (p for trend=0.036) in the second survey. Compared with those who reported no ETS exposure in either survey, children who had a high ETS exposure level (>5 cigarettes/day) in either survey had lower growth rates in forced expiratory flow between 25% and 75% of forced vital capacity (FEF(25-75); ß= -0.104, p=0.020) and forced expiratory flow at 25% of forced vital capacity (FEF(25); ß= -0.077, p=0.027). A monotonic exposure-response effect was observed between ETS exposure and the deficits in the growth rate of FEF(25) and FEF(25-75.) CONCLUSIONS: Exposure to ETS increased the risks of respiratory symptoms in Chinese school-aged children and was associated with impaired lung function growth. A dose-response relationship was observed for the latter effect.

Physical activity, cardiorespiratory fitness, and obesity among Chinese children.

OBJECTIVE: To investigate the relationships of cardiorespiratory fitness (CRF) and physical activity (PA) with the risk of overweight/obesity in Chinese schoolchildren. METHODS: A total of 1795 children aged 8-13 years at baseline were followed-up for 18 months from 2006 to 2008 in Guangzhou, China. Children were categorized as "normal weight", "overweight", and "obese" using Chinese obesity cut-off points. Data on self-reported PA were obtained. CRF was determined by the 20-meter multistage fitness test, and the sex-specific median values were set as the cut-off points for the classification of high and low CRF. RESULTS: Significantly higher CRF was found in children with normal weight (from 6.55 to 8.65 ml/kg/min) or physically active children (from 0.42 to 1.22 ml/kg/min) compared with the reference group. CRF was inversely associated with the kg/m(2) change in BMI during the follow-up period (ß=-0.63 kg/m(2) and -0.64 kg/m(2) for boys and girls, respectively, both p<0.001). Significant association of baseline CRF with overweight/obesity was found in boys (odds ratio (OR) 8.71; 95% confidence interval (CI) 2.59-29.26, p<0.001), whereas the association was marginally insignificant in girls (OR 6.87; 95% CI 0.96-49.09, p=0.055). CONCLUSIONS: The results showed a strong negative association between CRF levels and children's BMI and weight gain.

Effects of ambient air pollution on lung function growth in Chinese schoolchildren.

OBJECTIVE: To evaluate the adverse effect of exposure to air pollution on lung function growth in school-aged children. METHODS: A cohort of 1983 children from three districts in Guangzhou, China was followed-up for 6 months. The children performed pulmonary function tests twice, and their parents reported the child's respiratory symptoms by self-administered questionnaires in both surveys. RESULTS: The annual mean concentrations of air pollutants for the past 5 years for particulate matter less than 10 microns in diameter (PM(10)), nitrogen (NO(2)), and sulfur dioxide (SO(2)) were respectively: 96.1 microg/m(3), 76.0 microg/m(3), and 65.7 microg/m(3) in the highly-polluted district (HPD), 80.3 microg/m(3), 67.6 mug/m(3), and 54.5 microg/m(3) in the moderately-polluted district (MPD), and 80.0 microg/m(3), 48.1 microg/m(3), and 52.2 microg/m(3) in the least-polluted district (LPD). After adjustment for potential confounders, significant deficits were found in the annual growth rates of forced expiratory flows at 25% (FEF(25)), and between 25% and 75% (FEF(25-75)) in boys and FEF(25) in girls (In boys, for FEF(25), -0.136 l/s, p = 0.008 in MPD and -0.153 l/s, p = 0.004 in HPD, respectively; for FEF(25-75), -0.176 l/s, p = 0.013 in MPD and -0.167 l/s, p = 0.021 in HPD, respectively. In girls, for FEF(25), -0.123 l/s, p = 0.043 in HPD), using LPD as the reference. Deficits in the annual growth rate of forced expiratory volume in 1 s (FEV(1)) were also negatively associated with air pollution in boys (-0.063 L, p = 0.032 in HPD). CONCLUSIONS: The study adds more evidence that exposure to air pollution has adverse effects on lung function growth in schoolchildren.

Interaction between continuous variables in logistic regression model / 中华流行病学杂志

Rothman argued that interaction estimated as departure from additivity better reflected the biological interaction. In a logistic regression model, the product term reflects the interaction as departure from multiplicativity. So far, literature on estimating interaction regarding an additive scale using logistic regression was only focusing on two dichotomous factors. The objective of the present report was to provide a method to examine the interaction as departure from additivity between two continuous variables or between one continuous variable and one categorical variable.We used data from a lung cancer case-control study among males in Hong Kong as an example to illustrate the bootstrap re-sampling method for calculating the corresponding confidence intervals.Free software R (Version 2.8.1) was used to estimate interaction on the additive scale.

Mental health issues in Chinese offshore oil workers.

BACKGROUND: Offshore oil platform work is regarded as a stressful occupation, and occupational stress has been shown to be an important risk factor for mental illness. Little, however, is known about the main and interactive effects of occupational stress and coping styles on the mental health of Chinese offshore oil platform workers. AIMS: To explore the association of mental health with occupational stress, coping styles and their interaction among Chinese offshore oil platform workers. METHODS: A cross-sectional survey was conducted among 561 Chinese offshore oil platform workers. They were sent a self-administered questionnaire exploring their socio-demographic characteristics, occupational stress, coping styles and mental health. Hierarchical multiple regression was used to assess the main and interactive effects of occupational stress and coping styles on mental health. RESULTS: After controlling for age, educational level, marital status and years of offshore working, poor mental health was significantly positively associated with occupational stress, 'internal behaviour' coping methods and the interaction between occupational stress and internal behaviour coping. CONCLUSIONS: The results of this study suggest that the mental health of Chinese offshore oil platform workers is associated with occupational stress, some coping styles and interactions of occupational stress and some coping styles.

Influence of occupational stress on mental health among Chinese off-shore oil workers.

AIM: To explore the influence of occupational stress on mental health in off-shore oil production. METHODS: A cross-sectional survey was conducted among 561 Chinese off-shore oil workers. The workers were invited to fill in a self-administered questionnaire exploring their socio-demographic characteristics, occupational stress levels, and 12-item general health questionnaire. A hierarchical multiple regression procedure was used to assess the effects of occupational stress on mental health. RESULTS: After controlling for age, educational level, marital status and years of off-shore work, poor mental health was found to have a significant positive association with seven of the nine identified sources of occupational stress. They were: conflict between job and family/social life, poor development of career and achievement at work, safety problems at work, management problems and poor relationship with others at work, poor physical environment of the work place, uncomfortable ergonomic factors at work, and poor organizational structure at work. All of these occupational stress sources together explained 19.9% of the total variance. CONCLUSIONS: The results confirmed that occupational stress was a major risk factor for poor mental health among Chinese off-shore oil workers. Reducing or eliminating occupational stressors at work would benefit workers' mental health.

Birth weight and lung function in a cohort of Chinese school children.

OBJECTIVE: Evidence on the association between birth weight and lung function is conflicting. We evaluated the children's lung function in relation to their birth weight in China. METHODS: A prospective cohort study was conducted in 1,599 school children. Baseline data on birth weight and other potential confounding variables were obtained from self-administered questionnaires. Pulmonary function tests were performed with a standard procedure and repeated 6 months later. RESULTS: There were no significant differences in the standard deviation score (SDS) of forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) between children with low birth weight (LBW) and those with normal birth weight (NBW). The growth rates in lung function between children with LBW and NBW were also insignificant. CONCLUSIONS: No association between birth weight and lung function was found among Chinese school children.

Direct and interactive effects of occupational stress and coping on ulcer-like symptoms among Chinese male off-shore oil workers.

BACKGROUND: Off-shore oil production is widely regarded as a stressful occupation and digestive system problems were commonly observed in off-shore oil workers. Is occupational stress from off-shore oil work associated with the occurrence of digestive problems among off-shore oil workers? And are coping styles also related to their occurrence? The aim of this study was to explore the direct and interactive association of occupational stress and coping styles with ulcer-like symptoms in Chinese male off-shore oil workers. METHODS: A cross-sectional survey was conducted among 561 Chinese male off-shore oil workers. They were invited to fill in a self-administered questionnaire exploring their socio-demographic characteristics, occupational stress, coping style, and ulcer-like symptoms. A stepwise multiple regression procedure was used to assess the direct and interactive effects of occupational stress and coping behaviors on ulcer-like symptoms. RESULTS: After controlling for age, educational level, marital status and years of off-shore working, the ulcer-like symptoms were significantly positively associated with occupational stress and "internal behavior" coping methods, negatively associated with external/social behavior coping methods, and positively associated with the interaction between occupational stress and internal behavior coping. CONCLUSION: The results of the present study suggest that occupational stress was associated with gastric health problems and that this association might be moderated by certain coping behaviors.

Study on the interaction under logistic regression modeling / 中华流行病学杂志

When study on epidemiological causation is carried out,logistic regression has been commonly used to estimate the independent effects of risk factors.as well as to examine possible interactions among individual risk factor by adding one or more product terms to the regression model.In logistic or Cox's regression model.the regression coefficient of the product term estimates the interaction on a muhiplicative scale while statistical significance indicates the departure from multiplicativity.Rothman argues that when biologic interaction iS examined,we need to focus on interaction as departure from additivity rather than departure from multiplicativity.He presents three indices to measure interaction on an additive scale or departure from additivity.using logarithmic models such aS logistic or Cox's regression model.In this paper,we use data from a case-control study of female lung cancer in Hong Kong to calculate the regression coefficients and covariance matrix of logistie model in SPSS.We then introduce an Excel spreadsheet set up by Tomas Andersson to calculate the indices of interaction on an additive scale and the corresponding confidence intervals.The results can be used as reference by epidemiologists to assess the biologic interaction between factors.The proposed method is convenient and the Excel spreadsheet is available online for free.

Socioeconomic distribution of health and health care utilization in a new town in Hong Kong, China.

OBJECTIVES: To assess the association of socioeconomic indicators with various chronic and acute illnesses and the utilization of public health care in a new town in Hong Kong, China. METHODS: Illness experience and socioeconomic and demographic data of 7570 residents from 2022 randomly selected households were collected through telephone interviews. The relationships between socioeconomic indicators and illnesses/choice of health care were explored using stepwise logistic regressions after adjusting for sex and age. RESULTS: Significant positive associations were noted between low household income and diabetes mellitus, any chronic illnesses among adults and flu among younger subjects; low educational level and accident-related illness among adults; being born in Chinese mainland and flu, any acute illness in adults. For the utilization of public health care, low household income was the most consistent risk factor. CONCLUSION: This study did not demonstrate a unidirectional socioeconomic gradient in health but supported the hypothesis that socioeconomic deprivation was associated with the utilization of public health care.

Cluster of SARS among medical students exposed to single patient, Hong Kong.

We studied transmission patterns of severe acute respiratory syndrome (SARS) among medical students exposed exclusively to the first SARS patient in the Prince of Wales Hospital in Hong Kong, before his illness was recognized. We conducted a retrospective cohort study of 66 medical students who visited the index patient's ward, including 16 students with SARS and 50 healthy students. The risk of contracting SARS was sevenfold greater among students who definitely visited the index case's cubicle than in those who did not (10/27 [41%] versus 1/20 [5%], relative risk 7.4; 95% confidence interval 1.0 to 53.3). Illness rates increased directly with proximity of exposure to the index case. However, four of eight students who were in the same cubicle, but were not within 1 m of the index case-patient, contracted SARS. Proximity to the index case-patient was associated with transmission, which is consistent with droplet spread. Transmission through fomites or small aerosols cannot be ruled out.

A case-control study of eye injuries in the workplace in Hong Kong.

OBJECTIVE: Eye injury in the workplace is common worldwide. This study proposed to explore both risk and preventive factors re eye injuries in Hong Kong. DESIGN: Case-control study. PARTICIPANTS: A total of 239 work-related eye injury patients, and 253 subjects without a history of any eye injury as controls. METHODS: Patients with all incident cases of work-related eye injuries attending the ophthalmology clinics of 3 major public hospitals in Hong Kong during the first 3 months of 2000 were invited to participate. Controls were selected from the general population and were frequency matched to patients based on gender. Patients were interviewed face-to-face by trained interviewers in the ophthalmology clinics, using a structured questionnaire. Telephone interviews were used for controls. MAIN OUTCOME MEASURES: Risk and protective factors associated with eye injuries. RESULTS: Among eye injury cases, 158 patients (66.1%) reported having incurred 1 episode of eye injury during employment, 49 (20.5%) having suffered 2 episodes, and 32 (13.4%) having experienced >/==" BORDER="0">3 eye injuries at work. Most of the patients (85.4%) did not wear any protective devices at the time of injury. Subjects who wore safety glasses regularly were less likely to have eye injuries (odds ratio [OR] = 0.29, 95% confidence interval [CI] = 0.14-0.62). Having a safety requirement for wearing safety glasses was negatively associated with eye injuries (OR = 0.31, 95% CI = 0.15-0.62). Multivariate analysis indicated that exposures to certain work hazards and working in the construction industry were positively associated with eye injuries. Subjects who worked longer in their current job, who reported having received job safety training before employment, or whose machines or equipment were maintained or repaired regularly by employers were at lower risk of experiencing eye injuries. CONCLUSIONS: Construction workers and those exposed to multiple hazards may get eye injuries at work. They should be provided with protective devices that are effective in preventing such exposures. Health education and safety training are important in preventing eye injuries. Maintenance and repair of machines and equipment may effectively reduce or eliminate the sources of exposures.

Can schoolchildren provide valid answers about their respiratory health experiences in questionnaires? Implications for epidemiological studies.

To evaluate the relative validity of information on children's respiratory experience given by different informants, we examined and compared the relationship between low ventilatory function (defined as more than 1 standard deviation below the corresponding mean) and schoolchildren's respiratory symptoms or illnesses reported separately by the children and their parents, using a standard respiratory questionnaire. A total of 1,963 children aged 8-12 years from 12 primary schools in three districts of Hong Kong provided parent-completed and self-completed questionnaires, as well as acceptable spirometric measurements. Prevalence of low forced expiratory volume ratio (FEV1/FVC) and low forced expiratory flow rate between 25-75% of FVC (FEF25-75) were higher among those with either parent or child-reported symptoms/illnesses. Child-reported cough and phlegm performed better than the corresponding parent-reported symptoms in predicting low FEV1/FVC. The contrary was true for wheezing and bronchitis. For low FEF25-75, parent-reported wheezing, asthma, and bronchitis performed better, while the opposite was true for cough. Subgroup analysis by age showed that for older children (age 10 or above), child-reported symptoms/illnesses performed better in general in the prediction of low FEV1/FVC. On the other hand, parent-reported symptoms/illnesses seemed to have an advantage over child-reported ones in predicting low FEF25-75. Subgroup analysis by sex did not reveal any clear pattern. Overall, there was little difference between respiratory illness experiences reported by schoolchildren and their parents in terms of their associations with low ventilatory function. In a population-based study in which schoolchildren are subjects, it would be appropriate for respiratory questionnaires to be administered to the children themselves, especially if they have reached age 10. By doing so, higher response rates, and perhaps also better yields of correct information, may be obtained.

Awareness, treatment and control of hypertension in patients attending hospital clinics in China.

OBJECTIVES: To determine awareness, treatment and control of hypertension in patients attending hospital clinics in China. DESIGN: A cross-sectional survey. PATIENTS AND SETTING: Patients over the age of 35 years, who were attending outpatient clinics in 18 hospitals of eight major cities of Northern and Southern China, were interviewed face-to-face between June and July 1999. METHODS: Trained fieldworkers completed questionnaires regarding demographics, hypertension knowledge and awareness, treatment history and quality of life issues. Qualified physicians performed blood pressure assessment. RESULTS: A total of 9703 volunteers enrolled, of which 4510 (46.5%) were hypertensives. Among hypertensives, 23% were unaware of their high blood pressure. Although 89% of those aware reported receiving therapy, only 56% of them were taking medication regularly, and 33% were thus controlled. Although 69% of all hypertensives measuring at examination reported taking antihypertensive therapy, only 44% of them were actually taking medication regularly. Furthermore, 73% of hypertensives believed hypertension was not a serious problem, and required no regular medication. CONCLUSIONS: The results showed that a substantial number of outpatients have a hypertensive range of blood pressure. Although most of these patients are already being treated with drug regimen, the patient's misconceptions and lack of knowledge about the disease appear to be the major cause of treatment failure. The low rate of high blood pressure control for both sexes calls for further improvements.

A cross-sectional study of health-related behaviors in rural eastern China.

OBJECTIVE: This study examined the status of health-related behaviors among rural residents and the factors influencing the practice of such behaviors. METHODS: One thousand and ninety subjects aged 15 years or over in a rural community, Anhui Province, China were surveyed. A questionnaire was used to collect information on the health knowledge, attitude and behavior of the subjects. Information on health behavior included smoking, drinking, dietary habits, regular exercises, sleeping pattern and oral health behavior. RESULTS: The prevalence of smoking and drinking in the male subjects was 46.5% and 46.9%, respectively. There was a positive significant association between smoking and drinking. Only 8.3% of all subjects ate three regular meals a day regularly. Among subjects who ate two meals a day, 89.7% did not have breakfast. Only 1.7% of subjects took part in regular exercise. About 85% of subjects slept 6 to 8 h per day. Only 38.4% of the respondents had the habit of hand washing before eating and after using the lavatory. 79.3% of the subjects brushed their teeth every day, and among them, only 10.6 percent brushed their teeth twice a day. Further analyses showed that 64.8% of subjects had 3-5 items of positive health behaviors out of 8 items and only 16.9% had six or more items. Logistical regression analyses suggested that better health behavior was affected by sex, age, years of education, income and health knowledge. CONCLUSION: The status of health behaviors among rural residents was generally poor. It is thus urgent to reinforce health education in rural communities in China.