Association Between Community Social Capital and Suicide Mortality in Rural Areas of Japan: An Evaluation of Temporal Changes

Abstract

Background: Although previous studies have reported that suicide mortality was associated with social capital, the relation between social capital and suicide mortality has remained controversial. Thus, we evaluated the relation between social capital and suicide mortality in rural areas of Japan, and examined the association between temporal changes in social capital and suicide mortality over the last ten years. Methods: We examined the Standardized Mortality Ratio (SMR) for suicide for 26 municipalities of Miyazaki Prefecture and used the data to calculate the average suicide SMRs for two five-year periods: an earlier period, 2004–2008; and a later period, 2012–2016. Social capital (social cohesion and social participation of older people) was measured using information from questionnaire surveys. A multiple linear regression analysis of suicide SMR was conducted for each social capital variable, adjusting for potential confounding factors (population density, the proportion of older people, annual divorce rate, unemployment rate, and proportion of workers engaged in primary industries). Results: We demonstrated that male suicide SMR for the earlier period was significantly and positively associated with social cohesion after the adjustment of confounding factors. Temporal changes in male suicide SMRs were significantly and negatively associated with temporal changes in the social participation of older people in the adjusted model. No association was found for female suicide SMRs in either period. Conclusion: The present findings suggest that the social participation of older people might reduce suicide among males.