Reuterwall C (1,2), Ahlbom A (3), Doderichsen F (4), de Faire U (3,5), Hallqvist J (4), Hogstedt C (1,2), Perchagen G (3), Theorell T (4,6), Wolk A (7), and the Sheep Study Group. (1) National Institute for Working Life, Solna / Karolinska Hospital and Institute, Stockholm: (2) Department of Occupational Medicine, (3) Institute of Environmental Medicine, (4) Department of Public Health Sciences, (5) Department of Cardiovascular Medicine; (6) National Institute for Psychosocial Factors and Health; (7) University Hospital, Uppsala; the Medicine Departments at all 10 emergency hospitals in the Stockholm County, Sweden.
Aim: The Stockholm Heart Epidemiology Program (SHEEP) was initiated to test several hypotheses concerning risk factors for myocardial infarction (MI), such as exposures to occupational, social, environmental, life style, and biological factors. Special focus is on gender differences and on interaction between the various risk factors.
Method: SHEEP is a population based case-referent study covering all residents in the Stockholm county aged 45-69 yrs (~600,000 persons). Cases (n~2300, whereof ~780 women) were all persons who experienced a clinically diagnosed first event of acute MI during 1992-1993 (women also 1994); referents (1/case), stratified for sex and age, were chosen randomly from the population. Here we present results from the non-fatal cases and their referents.
Results: Odds Ratios from Logistic Regression Analysis (insert table)
*The analyses were adjusted for the following factors: Job strain for factors a,s,hw; smoking for a,j,hw; diabetes for a,d,j,s,hw; S-cholesterol for a,d,j,s,hw, where a=age, d=diabetes, hw=hip/waist ratio, j=job strain, and s=smoking. S-cholesterol cut off point = 6.5 mmol/l.
The relative risks are higher in women. Taking into account that the base line risk is higher in men than in women, the results might, however, indicate that the risk difference is smaller.
Tsutsumi A (1,2), Theorell T (2,3,4), Hallqvist J (5), Reuterwall C (4,6), and the Sheep Study Group. (1) Akaike Town Hospital, Tukuoka, Japan; (2) National Institute for Psychosocial Factors and Health, Stockholm, Sweden; (3) Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden; (4) Department of Occupational Health, Karolinska Hospital, Stockholm, Sweden; (5) Department of International Health and Social Medicine, Karolinska Institute, Stockholm, Sweden; (6) National Institute for Working Life, Solna, Sweden.
Aim: The combination of high psychological demands and low decision latitude is more frequent in subjects with myocardial infarction (MI) in most studies published so far. IN the SHEEP (Stockholm Heart EpidEmiology Program) study we can (1) explore methodological aspects (e.g., important recall bias) and (2) adjust for biomedical as well as psychosocial potential risk factors other than job strain.
Method: SHEEP is a population based case-referent study covering all residents in the Stockholm county aged 45-69 yrs (~600,000 persons). Cases (n~2300) were all persons who experienced a clinically diagnosed first event of acute MI during 1992-1993 (women also 1994); referents (1/case), stratified for sex and age, were chosen randomly from the population. Here we present results from a restricted set of subjects, viz., those occupationally active and working full time, aged 4564 yrs. The self-reported observation was derived form a Swedish version of the Karasek-Theorell demand-control questionnaire and job strain was defined by the upper quartile of the quotient (demand-latitude).
Results: Exposure to job strain was more common among cases (men: OR= 1.4, 95% CI 1.0-1.8; women: OR= 2.3, 95% CI 1.2-4.4; from logistic regressions) after adjustment for age, supervision status, night work, shift work, overtime work, HDL- and LDL- cholesterol, and smoking. Using chest pain preceding MI (a condition that could influence both work description and work career) as an explanatory variable, strengthened the observed associations.
Conclusion: Self-reported job strain was associated with MI status, even after adjustment for certain potential confounders, The association was stronger and more consistent for women than for men.
Uehata T, Sekiya A, Ishihara S, Saito Y, Doi Y. Department of Epidemiology, The Institute of Public Health, Japan Workers Stress and Health Survey (JAST) Group.
Purpose: To know the work-related risk factors of cardiovascular diseases such as sudden heart failure, ischemic heart disease and cerebral stroke which are known as Karoshi in middle-aged Japanese workers.
Methods: 16,700 male workers in 258 workers unions of 16 industrialized fields for ages 30-59, were registered by self-reported questionnaires of their health and life habits, consisting of 145 items including weekly working hours, monthly overtime, night duties, job stress, type A behavior, and Karasek’s demand/control model from 1989-1982. After 1.5-2.0 years, new onset of cardiovascular disease was surveyed by questionnaires and interviews, and was compared with non-onset workers matched with age and job of work-stress and other life habits factors in baseline datas.
Results: 102 workers were confirmed as new onset of cardiovascular diseases including 28 cerebral strokes, 73 heart attacks, and 1 aortic rupture. Compared with control workers, these cases were quantitatively more working in hours and qualifitatively had more work stress both in job pressure and subjective complaints at the questionnaire of baseline survey.
Conclusion: It was thought that work-related background of Japanese Karoshi cases caused by overwork were showed by epidemiological findings.
Bach E (1), Alfredsson L (2), Hammar N (3), Tuchsen F (1). (1) National Institute of Occupational Health, Copenhagen, Denmark; (2) Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden; (3) ?
Aims: The main purpose of the present study is to identify occupations with an excess risk of AMI by pooling data from Denmark and Sweden.
Methods: The International Classification of Diseases is a useful tool which facilitates international comparison of disease rates. The International Classification of Occupations and The International Standard Industrial Classification of All Economic Activity should facilitate international comparison of occupations and industries, but national extensions and especially national exceptions are a major obstacle. Denmark has chosen to use a newer version of the ISCO-classification than the other Nordic countries. For demographic analyses comparison on a less specific level was used in former comparison of cause specific mortality, but this approach is not satisfactory for identification of high risk groups.
Results: This study demonstrates to some extent that it is possible to compare specific occupations and the results are cost effective. An increases risk for men of acute myocardial infarction (AMI) was found among cannery workers, slaughterhouse workers, chemical industry workers, rubber workers, and ‘other metal workers’. A formerly found zero effect was supported for male paper and foundry workers. The results were especially interesting for women due to the small number of employees in each country. This study supports the fact that female brewery workers, cannery workers, slaughterhouse workers and rubber workers may have an increased risk of AMI.
Conclusion: Twenty occupations were of interest for comparison, but it was only possible to pool nine of them. Incompatibility due to different classification was a hindrance for comparison of the remaining occupations. Since the results for most of the none occupations are convincing we recommend and increased use of Nordic data and to pay more attention to their compatibility.