Background Few studies have examined the health effects of employment situation among women, taking social and economic conditions into consideration. The objective of this research was to investigate the association of employment situation (full-time or part-time employee and self-employed) with mortality risk in women over a 20-year follow-up period. Additionally, we examined whether the association between employment situation and mortality in women differed by education level and marital status.

Methods We investigated the association of employment situation with mortality among 16 692 women aged 40–59 years enrolled in the Japan Collaborative Cohort Study. Multivariate HRs and 95% CIs for total deaths by employment situation were calculated after adjustment for age, disease history, residential area, education level, marital status and number of children. We also conducted subgroup analysis by education level and marital status.

Results Multivariate HRs for mortality of part-time employees and self-employed workers were 1.48 (95% CI, 1.25 to 1.75) and 1.44 (95% CI, 1.21 to 1.72), respectively, with reference to women working full-time. Subgroup analysis by education level indicated that health effects in women according to employment situation were likely to be more evident in the low education-level group. Subgroup analysis by marital status indicated that this factor also affected the association between employment situation and risk of death.

Conclusions Among middle-aged Japanese women, employment situation was associated with mortality risk. Health effects were likely to differ by household structure and socioeconomic conditions.