Is the impact of job control on stroke independent from socioeconomic status?: A large-scale study of the Swedish working population

Background and Purpose - The main purpose of this study was to test whether the impact of job control on stroke mortality is independent of socioeconomic factors. Methods - This was a register- based cohort study of nearly 3.5 million working people ( 25 to 64 years of age in the 1990 Swedish Census) with a 5- year follow- up for stroke mortality. Job control was aggregated to the data from a secondary data source ( job exposure matrix). Gender- specific Poisson regressions were performed. Results - Compared with high job control occupations, low job control was significantly related to hemorrhagic ( relative risk, 1.54; 95% CI, 1.10 to 2.17) and all- stroke mortality ( relative risk, 1.50; 95% CI, 1.11 to 2.03) in women but not in men. The significance of job control in women was independent of all confounders included ( marital status, education level, and occupational class). Class- specific analyses indicated a consistent effect of job control for most classes ( significant for female lower nonmanuals). However, low job control did not increase the risk of stroke mortality in upper nonmanuals. Conclusions - Job control was significantly related to hemorrhagic and all- stroke mortality in women but not in men.