Tion and coronary heart disease. We evaluated data on a series of 568 married men who died of coronary heart disease and an equal number of controls matched for age, sex, and neighborhood of residence. Information was collected from the wives of both cases and controls on a large number of variables, including usual occupation, job-related and leisure-time physical activity, medi- cal history, and life-style. Usual occupation was dichotomized into blue-collar and white-collar work according to the Edwards classification. White-collar workers had a statistically significant 30% decreased risk of fatal coronary heart disease compared with blue-collar workers once the effects of reported coronary risk factors were considered (relative risk, 0.70; 95% confidence limits, 0.5 to 0.96). These data suggest that occupation is significantly associated with fatal coronary heart disease, and that this increased risk is not explained by a large number of known coronary risk factors. It still remains unclear, however, whether other uncontrolled variables explain the observed association. (JAMA 1987;258:791-792) DESCRIPTIVE data indicate that cor¬ onary heart disease is generally more common in wealthy, industrialized countries than in developing nations.1 Moreover, at least through the late 1960s, within any single country rates of coronary heart disease rose as the over¬ all level of affluence increased.2 These observations suggest a positive rela¬ tionship of socioeconomic status with risk of coronary heart disease. To inves¬ tigate this, a number of analytic studies have explored the association between occupation, a major component of socio- economic status, and coronary heart disease. While some studies have found no clear relation,3 others have reported a significant inverse association be¬ tween occupational status and coronary heart disease, with individuals in oc¬ cupations representing higher socioeco¬ nomic status having lower risks.46 Such a finding is opposite to what would have been formulated from descriptive data. Any observed inverse association may result from occupation being a marker for other differences between the groups that are related to risk of coronary heart disease. For example, level of physical activity and history of cigarette smoking are independent cor¬ onary risk factors. If they also vary by occupation, they could account, at least in part, for any observed differences in coronary heart disease rates. To investi¬ gate these possibilities, we evaluated data on occupation, other risk factors, and mortality due to coronary heart disease in a case-control study.