Kivimäki M, Virtanen M, Elovainio M, Kouvonen A, Väänänen A, Vahtera J. Work stress in the etiology of coronary heart disease-a meta-analysis. Scand J Work Environ Health 2006;32(6 special issue):431-442.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.
MethodsA 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.
ConclusionsObservational 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.Key terms cardiovascular disease; effort-reward imbalance; job strain; mortality; organizational justice; prospective cohort study; psychosocial factors; systematic review; working population. Activation of the stress system in the hypothalamus and the brain stem helps the body to overcome the influence of short-term physical stressors. However, prolonged overactivity of these systems may cause wear and tear and play a role in coronary heart disease (CHD), infection, and accelerated aging (1). The recognition that the physiological reactions to stress cannot only protect, but also damage the body has provided a basis for epidemiologic research on work stress.Three models for work stress and coronary heart disease Work-stress models aim at describing factors that are likely to elicit harmful stress at work in a large proportion of employees. These factors are conceptualized at a level of generalization that allows for their identification in a wide range of occupations. The stress model most often cited and most widely tested is the two-dimensional job-strain model (2-4) ( Work stress in the etiology of coronary heart disease strain model adds...