Coronary Heart Disease Attributable to Psychosocial Stressors at Work

BACKGROUND: Psychosocial stressors at work, including job strain and effort-reward imbalance (ERI), have been associated with an increased risk of coronary heart disease (CHD). However, the proportion of CHD events attributable to these exposures has not been quantified in a prospective cohort study. OBJECTIVES: The purpose of this study was to estimate the fraction of CHD events attributable to psychosocial stressors at work in a 20-year prospective cohort study. METHODS: This prospective cohort study included employees from public and semipublic organizations in Quebec City, Canada, followed from 2004 and 2018. A total of 6,295 participants without cardiovascular disease at baseline were included. Job strain and ERI were assessed using validated instruments. Incident CHD events were identified through universally covered health care databases. Attributable fractions were estimated using the Kaplan-Meier method. Multiple imputation and inverse probability weighting were applied to address selection and confounding. The first 5 years of follow-up were excluded to minimize reverse causation. RESULTS: During 15-year follow-up, 669 CHD events occurred over 112,297 person-years, yielding a CHD incidence rate of 5.96 per 1,000 person-years. The attributable fraction for job strain was 18.2% (95% CI: 1.8%-34.7%), and for ERI, it was 3.3% (95% CI: -1.6% to 8.2%). Combined exposure to both stressors resulted in an attributable fraction of 19.5% (95% CI: 0.7%-38.4%). CONCLUSIONS: In this cohort, combined exposure to job strain and ERI accounted for approximately one-fifth of CHD events. Findings suggest that psychosocial stressors at work could be relevant targets for reducing the burden of CHD through prevention strategies.