Objectives: This study focused on estimating the relative risk of coronary heart disease (CHD) in association with work stress, as indicated by the job-strain model, the effort-reward imbalance model, and the organizational injustice model.
Methods: A systematic review and meta-analysis of prospective cohort studies were carried out. Studies were eligible if they had published a quantitative estimate of the association between work stress and incident CHD or cardiovascular mortality by January 2006.
Results: Fourteen prospective cohort studies were identified. For a total of 83 014 employees, the age- and gender-adjusted relative ratio of CHD for high versus low job strain was 1.43 [95% confidence interval (95% CI) 1.15-1.84], but the ratio decreased to 1.16 (95% CI 0.94-1.43) after adjustment for risk factors and potential mediators. The age- and gender-adjusted risk ratio for a combination of high efforts and low rewards was 1.58 (95% CI 0.84-2.97) for 11 528 employees, and no reduction in the risk ratio was seen after further adjustments. For organizational injustice, the age- and gender-adjusted, and multiple-adjusted relative risks were 1.62 (95% CI 1.24-2.13) and 1.47 (95% CI 1.12-1.95), respectively, for a population of 7246 men and women. There was little standardization in the assessment of work stress within all three stress models, and significant heterogeneity in the effects of stress was observed between studies. Few studies were available for female samples.
Conclusions: Observational data suggest an average 50% excess risk for CHD among employees with work stress. Further research is needed to confirm that a reduction in work stress will lead to a reduction in CHD risk.