Do changes in effort-reward imbalance at work contribute to an explanation of the social gradient in angina?

AIMS To determine whether an increase in effort-reward imbalance over time increases the risk of angina, and whether such increases are associated with lower occupational position. METHODS Effort-reward imbalance (ERI) at work was measured in the Whitehall II occupational cohort of London based civil servants at baseline (1985-88) and in 1997. Coronary heart disease was measured in a self-reported health questionnaire by combining the Rose Angina Questionnaire with doctor diagnosed angina in 2001. RESULTS Among men, increase in ERI over time was associated with an increased risk of incident angina. Moreover, as increases in ERI were more common among lower grade civil servants, change in imbalance, to some extent, contributed to explaining the social gradient in angina. Among women, increases in imbalance were not associated with risk of angina, and therefore did not contribute to the explanation of the social gradient. CONCLUSIONS Reductions in effort-reward imbalance at work may reduce the risk of coronary heart disease among men.