89 male workers of vapor iron were subjected to the study. The investigation of labor evironment and worker conditions showed that: indoor temperature exceeds that of hygiene standard by 0,2-1,0oC, humidity and wind velocity is tense (2080 movement for each shift) working movement duration is short (12 second for each movement), in the shift, breaking time is insufficient to meet the need of rest. After a working day, memory, the attention, the tonus of muscle decrease dramatically in comparing with those before the shift the decrease is significant statistically. Many sites of pain occur considerably and concentrate in the nape, right arm, back, thigh and knee
Environment ; Hospitals ; Healthy Worker Effect

The basic advantages in the national tuberculosis control programme: policies of our government and party, the public health system and health worker worldwide in whole country, support from International organization. The disadvantages in tuberculosis control programme: survey of epidemiology on tuberculosis were n’t taken in all country, HIV/AIDS epidemic, tuberculosis resistance/ antidrug, lack of health workers for tuberculosis control, manage and control the private health system is limited, shortage finance. The solving method in the future: the stable method is communication activities and immobilization aids from society, finance and human resources serve for tuberculosis control, combination of private healthy that take part in the activities of tuberculosis control, but first of all must maintain a good observation programme for tuberculosis and survey of epidemiology on tuberculosis
Tuberculosis ; Healthy Worker Effect ; health

The working environment of 138 workers at Binh Dinh construction factory was studied concerning the harmful factors determined by the Institute of Occupational Medicine and Working environment. Almost harmful factors are highest then allowed standard, especially total dust (>3,7 times), high SiO2 content level 24-42%. In almost studied field, the noise density is higher than standard (90 dBA). There is a high incidence of some diseases such as stomato-dental diseases (50,27%), ENT and respiratory diseases (37,14%). Occupational safety and health care for workers were neziligible; commonly available masks for respiration are not proper for filtering the dust
Environment ; Healthy Worker Effect ; Health

Study was performed in the mountainous district of Mai Son and the plain district of Vinh Bao. 560 health workers at commune level were interviewed by a questionnaire designed of opened and semi opened questions on the skill and the practices of these workers. The authors showed that the knowledges and the skills on health education of health workers are very limited. High percentages of them have no awareness on the skills, the contents, and the management of their duty. This issue raises the necessary of train and retrains for these health workers on health education and manage of this activity
Medical Staff, Healthy Worker Effect, Knowledge

In the year 2001, the influence of working environment of the tunel of Hoa Binh hydraulic power station on workers’ labour capacity was studied. Results show that in a shift of workers, the decline of capacity accounts for 39.71% generally for some occupational function, the most decreased is loss of memory (60.88%). Between two shifts the less rest time, the more decrease of capacity. The degree of decline of labour capacity increases progressively along the occupational age
Healthy Worker Effect ; Occupational Diseases ; Health Occupations

OBJECTIVES: The strategy for the labor flexibility through subcontracted labor have brought a negative effect on the lives of the workers, such as the increase of the unstable employment. This study was conducted to analyze the relationship between the employment of subcontracted firms and the health status of them, and to find out some problems which have been caused in the process of health evaluation and the characteristics of social exclusion. METHODS: We reviewed the periodical health examination and preemployment health examination in order to compare health status of the subcontracted workers with those of the parent firm workers. The SF-36 questionnaire was administered to assess the self-perceived health status. RESULTS: The result shows that compared to the working duration of the parent firm workers, those of the subcontracted workers were shorter, and the job transfer rate was higher. In the periodical health examination, the prevalence of occupational and general disease was higher in the parent firm(10%) than in the subcontracted firms(6%). Preemployment health examination plays an important role in worker's health management. Among 6,260 workers who received preemployment health examination, the prevalence of disease was 37.9%. Mean scores of health status measured by SF-36 were lower in the subcontracted firm than in the parent firm. CONCLUSIONS: Due to social exclusion of the subcontracted workers from the periodical health examination, there is a possibility that the periodical health examination have the healthy worker effect. These results suggests that the preemployment health examination could be a more appropriate indicator which is able to assess the health status of the subcontracted workers than the periodical health examination.
Employment ; Healthy Worker Effect ; Humans ; Parents ; Pliability ; Prevalence ; Questionnaires

OBJECTIVES: The present study was designed to determine the characteristics of shift work and the relationship between shift work and the level of self-rated health using the Korean Labor and Income Panel Study (KLIPS) data, which represents urban households in Korea. METHODS: Using the 9th wave of KLIPS, this study analyzed 2,087 male workers aged 25 to 64 years; participants missing data were excluded from analysis. To determine the impact of shift work on the level of self-rated health, logistic regression analysis was applied that controlled for socio-demographic characteristics, labor environment, and health-related behaviors. RESULTS: Shift workers comprised 13.4% of study subjects overall. The majority(69.2%) of participants were in 2-teams and in 2-shifts. Week 1 shift cycle changes were the highest, 56.3%. The risk of poor self-rated health was not significantly higher among shift workers compared to non-shift workers (OR=1.08, 95% CI=0.79~1.48). When divided by tenure, shift workers with more than 10-years experience (OR=1.79, 95% CI=0.91~3.50) tended to show greater risk than non-shift workers at marginal significance. CONCLUSIONS: In the present study, a significantly higher risk of self-rated poor health among shift workers was not observed. However, shift workers with more than 10-years experience tended to show increased health risk compared to non-shift workers. Further studies are required to determine time-series data and to consider both healthy worker effect and information bias.
Aged ; Bias (Epidemiology) ; Family Characteristics ; Healthy Worker Effect ; Humans ; Korea ; Logistic Models ; Male

PURPOSE: The healthy worker effect is an important issue in occupational epidemiology. This study was conducted to propose a new method to test the relation between exposure and mortality in the presence of the healthy worker effect. METHODS: In this study, the healthy worker hire effect was assumed to operate as a confounding variable of health status at the beginning of employment and healthy worker survival effect as a confounding and intermediate variable of employment status. In addition, the proposed method reflects the length bias sampling caused by changing of an employment status. Simulation studies were also carried out to compare the proposed method with Cox's time dependent covariates models . RESULTS: The theoretical development of the healthy worker survival effect is based on the result that an observation with change of an employment status requires that the survival time without intermediate event exceeds the waiting time for the intermediate event. According to our simulation studies, both the proposed method and Cox's time dependent covariates model which includes the change of employment status as time dependent covariates seem to be satisfactory at 5% significance level. However, Cox's time dependent covariates models without or with the change of employment status as time fixed covariate are unsatisfactory. The proposed test is superior in power to tests based on Cox's model. CONCLUSIONS: The healthy worker effect may not be controlled by classical Cox's proportional hazards models. The proposed method performed well in the presence of healthy worker effect in terms of level and power
Bias (Epidemiology) ; Confounding Factors (Epidemiology) ; Employment ; Epidemiology ; Healthy Worker Effect* ; Mortality ; Proportional Hazards Models

OBJECTIVES: The present study evaluated the effects of job stress, including organisational system to self-rated depression through a panel study of male municipal firefighters in the Republic of Korea. METHODS: A panel of 186 municipal firefighters reported self-rated depressive symptoms according to the Beck Depression Inventory (BDI). The effects of job stress were evaluated using the Korea Occupational Stress Scale, taken one year earlier and classified by the median value. Panel members were classified into Depression or Control groups according to BDI scores, with a cut-off level of \'over mild depression' in a follow-up survey. RESULTS: The Depression group included 17 (9.1%) workers. Firefighters who scored high on occupational system had an 8.3 times greater risk of being assigned to the Depression group than those who had not (adjusted odds ratio [OR] = 8.03, 95% confidence interval (CI) = [1.73-37.22]). In contrast, job stress from a \'difficult physical environment' revealed negative risks related to being classified in the Depression group (AOR = 0.20, 95% CI = [0.04-0.92]). CONCLUSIONS: Although the healthy worker effect may be involved, job stress based on perceptions of organisational system was a strong risk factor for depression. A comprehensive approach should be considered that encompasses social issues when assessing or mental health in high-risk groups, as well as the practical issue of physiochemical hazards.
Depression* ; Firefighters* ; Follow-Up Studies ; Healthy Worker Effect ; Humans ; Korea ; Male* ; Mental Health ; Odds Ratio ; Republic of Korea ; Risk Factors

Exposure to manganese (Mn) is associated with neurobehavioral effects. There is disagreement on whether commonly occurring exposures in welding, ferroalloy, and other industrial processes produce neurologically significant neurobehavioral changes representing parkinsonism. A review of methodological issues in the human epidemiological literature on Mn identified: (1) studies focused on idiopathic Parkinson disease without considering manganism, a parkinsonian syndrome; (2) studies with healthy worker effect bias; (3) studies with problematic statistical modeling; and (4) studies arising from case series derived from litigation. Investigations with adequate study design and exposure assessment revealed consistent neurobehavioral effects and attributable subclinical and clinical signs and symptoms of impairment. Twenty-eight studies show an exposure-response relationship between Mn and neurobehavioral effects, including 11 with continuous exposure metrics and six with three or four levels of contrasted exposure. The effects of sustained low-concentration exposures to Mn are consistent with the manifestations of early manganism, i.e., consistent with parkinsonism. This is compelling evidence that Mn is a neurotoxic chemical and there is good evidence that Mn exposures far below the current US standard of 5.0 mg/m3 are causing impairment.
Bias (Epidemiology) ; Healthy Worker Effect ; Humans ; Jurisprudence ; Manganese* ; Models, Statistical ; Neurobehavioral Manifestations ; Neuropsychological Tests ; Occupations* ; Parkinson Disease ; Parkinsonian Disorders* ; Welding