Occupational differences in suicide mortality among Japanese men of working age

•Over 10,000 Japanese men of working age commit suicide each year.•Suicide risk appears to vary across occupations and industries among Japanese men.•Administrative and managerial, services and agriculture had the highest suicide risk.•By industry, mining incurred by far the greatest suicide risk.•Interventions for preventing suicide are urgently needed in Japanese workplaces.

BackgroundAlthough 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.MethodsWe 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.ResultsSuicide 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).LimitationsBias 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.ConclusionsThese 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.