Article : Is Working Too Hard Really Bad for Your Heart?

A collaborative meta-analysis suggests that the effect is real but smaller than previously thought.

In a recent meta-analysis of published cohort studies, job strain was associated with about a 40% increase in risk for coronary heart disease. However, these studies are susceptible to publication bias and limited by methodological idiosyncrasies. To minimize these shortcomings, investigators conducted a participant-level meta-analysis of 13 published and unpublished European studies including 197,473 individuals (mean age, 42; 49% women). The same validated model was used in all of the studies to assess baseline job strain.

Fifteen percent of the cohort reported job strain, defined as high demands and low control. Compared with participants without job strain, those with job strain had a significantly higher risk for incident myocardial infarction or death from coronary artery disease (hazard ratio, 1.23). In separate analyses of published and unpublished data, the effect was higher in published studies than in unpublished studies (HR, 1.43 and 1.16, respectively), but remained significant in both when adjusted for age, sex, and socioeconomic status. The association was also significant in an analysis excluding coronary events that occurred within 3 years after baseline (HR, 1.31).


Kivimäki M et al. Job strain as a risk factor for coronary heart disease: A collaborative meta-analysis of individual participant data. Lancet 2012 Sep 14; [e-pub ahead of print].