A disease map of male suicide in Japan and its association with socioeconomic factors

INTRODUCTION: Suicide is well known as a major social problem in Japan, and the male suicide rate has been particularly high for many years. The present study shows a disease map of male suicides in Japan and explores associated factors that might prove useful for determining public health strategies in consideration of locality.

METHODS: We conducted an ecological study referring to government statistics, including vital statistics, municipality tax records, and a national census. The study population comprised Japanese men living in Japan in 2010. Relative risk of death from suicide in each municipality was used as an outcome variable, calculated from conditional autoregressive models. Trend analysis was also conducted to explore associated factors and examine the direction of association (i.e., negative or positive).

RESULTS: Hot spots of suicide were detected in the north and south of Japan. Income, local finance, proportion of doctors to local population and proportion of doctors to local gross area showed negative trends for relative risk of suicide. Unemployment rate and primary industry worker rate in area of residence showed positive trends for relative risk of suicide (all p-values <0.01).

CONCLUSIONS: Although the present study was designed as an ecological study and our findings need more precise investigation based on individual data, disparities in socioeconomic factors may help explain regional differences in suicide risk. Arrangement of doctors who can deal with mental health difficulties in hot spots of suicide may be warranted.