Coronary heart disease and mortality in middle aged men from different occupational classes in Sweden

In the Gothenburg primary prevention study 7083 middle aged men were classified into five categories by occupational state. A retrospective analysis of the data showed that low occupational class was associated with slight increases in smoking rates, systolic blood pressure, serum cholesterol concentration, body mass index, and heart rate. Alcohol abuse was strongly associated with low occupational class. After a mean of 11.8 years' follow up the incidence of coronary heart disease was found to be strongly and inversely related to occupational class. For death from coronary heart disease this association fell just below significance when other risk factors were taken into account, but the inverse association between non-fatal myocardial infarction and occupational class persisted even in multivariate analysis. A weak but independent inverse relation was found between occupational class and fatal cancer. Mortality from all causes in the lowest occupational class was 12% compared with 6% in the highest class, and this difference could only partly be explained by other factors. After 10 years a sub-sample of the men were examined again. Risk factors had decreased in all occupational classes, but the changes in risk were not associated with occupational class. Social class, defined by occupation, in Sweden is clearly related to the incidence of coronary heart disease.