Empirical studies on job strain and cardiovascular disease (CVD), their internal validity, and the likely direction of biases were examined. The 17 longitudinal studies had the highest validity ratings. In all but two, biases towards the null dominated. Eight, including several of the largest, showed significant positive results; three had positive, nonsignificant findings. Six of nine case-control studies had significant positive findings; recall bias leading to overestimation appears to be fairly minimal. Four of eight cross-sectional studies had significant positive results. Men showed strong, consistent evidence of an association between exposure to job strain and CVD. The data of the women were more sparse and less consistent, but, as for the men, most of the studies probably underestimated existing effects. Other elements of causal inference, particularly biological plausibility, corroborated that job strain is a major CVD risk factor. Additional intervention studies are needed to examine the impact of ameliorating job strain upon CVD-related outcomes.

Ninety reports of systematic evaluations of job-stress interventions were rated in terms of the degree of systems approach used. A high rating was defined as both organizationally and individually focused, versus moderate (organizational only), and low (individual only). Studies using high-rated approaches represent a growing proportion of the job-stress intervention evaluation literature. Individual-focused, low-rated approaches are effective at the individual level, favorably affecting individual-level outcomes, but tend not to have favorable impacts at the organizational level. Organizationally-focused high- and moderate-rated approaches are beneficial at both individual and organizational levels. Further measures are needed to foster the dissemination and implementation of systems approaches to examining interventions for job stress.

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New systems of work organization, such as lean production and total quality management, have been introduced by employers throughout the industrialized world to improve productivity, quality, and profitability. However, few studies have examined the impact of such systems on occupational injuries or illnesses or on job characteristics related to job strain, which has been linked to hypertension and cardiovascular disease. The studies reviewed provide little evidence to support the hypothesis that lean production "empowers" auto workers. In fact, auto industry studies suggest that lean production creates intensified work pace and demands. Increases in decision authority and skill levels are modest or temporary, whereas decision latitude typically remains low. Thus, such work can be considered to have job strain. In jobs with ergonomic stressors, intensification of labor appears to lead to increases in musculoskeletal disorders. The evidence for adverse health effects remains inconclusive for related new work systems in other industries, such as modular manufacturing or patient-focused care.