Socioeconomic and sex inequalities in health of Japanese civil servants with international comparisons: Role of job strain, work hours and work-family conflicts

Social inequalities in health and their international variations are well known. This review aims to summarize the results from a series of epidemiological studies on social inequalities in health among Japanese civil servants and their international comparisons. In the Japanese civil servants study, there were socioeconomic status (SES) and sex inequalities in job strain, work hours, and work-family conflicts. In general, low SES employees were more likely to have low job control, low job demands, low social support at work, and shift work. In addition, high SES female employees are more likely to have high work-to-family conflict. Women had low job control, high job demands, long work hours, shift work, high work-to-family conflict, and high family-to-work conflict. SES and sex inequalities in poor sleep and poor physical and mental functioning also existed (i.e. the lower the SES, the poorer the health; women had poorer health than men). Such SES and sex inequalities in health reduced considerably after adjustment for job strain, work hours and work-family conflicts. The findings from our international comparative studies on British, Finnish and Japanese civil servants indicate that, among Finnish men and women, SES inequalities in psychosocial stress were relatively smaller and work-family balances were better, which lead to somewhat smaller SES inequalities in physical health and rather reverse SES inequalities in mental health. Sex inequalities in low job control, high job demands, and long work hours among Finnish employees were also smaller than among British and Japanese employees, leading Finnish employees to have smaller sex inequalities in physical and mental functioning. These results suggest that SES and sex inequalities in job strain, work hours, and work-family conflicts are potential determinants of SES and sex inequalities in physical and mental health and their international variations. Universal and egalitarian treatment in Finnish social democratic welfare state regime may play a role in reducing social inequalities in health. However, in our comparative studies, the associations of work and family stresses with health risk behaviors were weak and inconsistent. In addition, while there were SES inequalities in health risk behaviors among British and Finnish men and women, such associations were not observed among Japanese men and women. These results suggest that work and family stresses have a limited value in explaining SES inequalities in health through health risk behaviors, particularly among Japanese employees. In conclusion, reducing SES and sex inequalities in job strain, work hours, and work-family conflicts may have beneficial effects on social inequalities in health.