Occupational differences in suicide mortality among Japanese men of working age

Abstract

Background: Although suicide rates among Japanese men of working-age have steadily increased over the past two decades, the distribution by occupation and industry is not uniform. Little is known regarding occupation and industry differences in relation to suicide risk. This study examined differences in suicide risk among Japanese men of working age (25-59 years) during 2010.

Methods: We analysed the Japanese government's 2010 national survey data regarding occupation and industry-specific death rates. Poisson regression models were formulated for each occupation and industry to estimate the relative risk of death by suicide. Potential interactions between age and occupation/industry were also examined.

Results: Suicide incidence was highest among workers in the fields of agriculture and mining. When compared with referent groups (sales for occupation and wholesale and retail for industry), the age-adjusted relative risk of suicide was highest for administrative and managerial workers (Incident Relative Risk [IRR]: 3.91, 95% Confidence Interval [95%CI]: 3.16-4.85), service industries (IRR: 3.63, 95%CI: 2.93-4.51) and agriculture (IRR: 3.53, 95%CI: 2.84-4.38) occupations, and for mining (IRR: 23.9, 95%CI: 19.4-29.4), fisheries (IRR: 6.26, 95%CI: 5.03-7.80), electricity and gas (IRR: 5.86, 95%CI: 4.71-7.30) and agricultural industries (IRR: 4.73, 95%CI: 3.78-5.91).

Limitations: Bias resulting from misclassification of deceased individuals' occupation or industry was a potential limitation of this study. Furthermore, detailed information regarding occupation-related factors, such as employment status, had not been recorded in the initial survey.

Conclusions: These findings help elucidate Japanese occupations and industries with a higher suicide risk, most likely due to economic changes or workplace factors relating to stress and depression.

Keywords: Industry; Japan; Mortality; Occupation; Suicide.