Job strain and prevalence of hypertension in a biracial population of urban bus drivers

Objectives. In this study we tested the association between occupational stress-as measured by job demands, decision latitude, and job strain-and hypertension in a population of 1396 Black and White bus drivers. Methods. Height, weight, blood pressure, and medical history were assessed by physical exam. Drivers completed a questionnaire assessing their work schedules, personal habits, and self-perceptions about job demands and decision latitude. Results. Univariate analyses revealed significant inverse associations; lower levels of job demands and job strain were associated with a higher prevalence of hypertension for Blacks and Whites. After 12 confounding variables were controlled for, the association between these two measures of occupational stress and hypertension became nonsignificant. Decision latitude was also not significantly associated with hypertension. Conclusions. Our findings are inconsistent with previous studies' findings of a positive association between job strain and chronic diseases. The difference in results may be explained by our incorporation of individuals' perceptions in the measurement of occupational stressors and our use of individuals from a single occupation with comparable job responsibilities and income, thus controlling for potential confounding by social class.