Job control, job demands and job strain and suicidal behaviour among three million workers in Sweden

Objective To investigate the association between job control, job demands and their combination (job strain) and suicide attempts and deaths among male and female workers in Sweden. Methods Job control and demands were measured separately for men and women using a job exposure matrix, which was linked to around three million individuals based on their occupational title in 2005. Suicide attempts and deaths were measured in the hospital and cause of death registers from 2006 to 2016. HRs were estimated using discrete proportional hazards models with annually updated age as the time axis. Models were adjusted for sociodemographic, family, health, labour market and childhood factors, as well as the time-varying effects of unemployment, sick leave and family factors during follow-up. Results Low job control was associated with an increased risk of suicide attempts and deaths among both men and women while high job demands tended to be associated with a decreased risk. The combination of job control and job demands (job strain) reflected the increased risk of low control jobs and the decreased risk of high demand jobs. Associations were attenuated but still present after adjustments. Conclusions Low job control is related to suicide attempts and deaths, and this is only partially explained by important covariates measured both prebaseline and during follow-up. Attempts to increase job control among workers may be beneficial in preventing suicide.