Background: This prospective cohort study examined the association between educational level and major causes of death in Japan.
Method: A baseline survey was conducted between 1988 and 1990 among 110,792 inhabitants of 45 areas aged 40-79 years. Follow-up surveys were conducted annually and causes of death were identified from death certificates. The analysis was restricted to 16,715 men and 23,284 women.
Results: During the follow-up period (377,139 person-years), 6628 deaths were recorded. Individuals with low levels of education had an increased overall risk of death [relative risk (RR)=1.16, 95% confidence interval (CI): 1.08, 1.25, in men; RR=1.26, 95% CI: 1.14, 1.39, in women], cancers (RR=1.17, 95% CI: 1.04, 1.32, in men; RR=1.10, 95% CI: 0.93, 1.30, in women), and death from external causes (RR=1.81, 95% CI: 1.29. 2.54, in men; RR=1.78, 95% CI: 1.18, 2.70, in women). Ischemic heart disease risk was marginally reduced in men with low levels of education (RR=0.77, 95% CI: 0.58, 1.01).
Conclusions: These results show that health inequalities exist in Japan, even though wealth inequalities are relatively low. Social and political initiatives will be needed to correct these inequities between different socioeconomic statuses.