Sociodemographic Factors, Health Behaviors, and Biological Indicators Associated With Suicide Mortality Among Young Adults in South Korea: A Nationwide Cohort Study Among 16 Million Men and Women

Abstract

Background: The role of sociodemographic factors, health behaviors, and biological indicators as potential risk factors for suicide is relatively understudied among young adults. The aim of this study is to determine the association of sociodemographic factors, health behaviors, and biological indicators on the risk of death from suicide among young adults. Methods and Findings: The study population consisted of 16,277,532 individuals aged 20-39 years from the Korean National Health Insurance Service. Sociodemographic factors, determined at 2005, associated with death from suicide during 2006-2015 were evaluated. Furthermore, 2,055,789 individuals who underwent health examinations between 2002-2005 were separately assessed for health behaviors and biological indicators associated with death from suicide. Cox proportional hazards regression analysis was used to determine the hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk of death from suicide according to sociodemographic factors (age, household income, job status, residence, and Charlson comorbidity index), health behaviors (smoking, physical activity, and alcohol consumption), and biological indicators (body mass index, blood pressure, fasting serum glucose, and total cholesterol). Low household income, non-employment, increased comorbidity, smoking, and normal weight elevated the risk of death from suicide among young adults. While older age was associated with elevated risk for death from suicide among men, older age reduced the risk for death from suicide among women. Elevated blood pressure and fasting serum glucose were associated with increased risk for death from suicide among men. Finally, high total cholesterol levels were associated with increased risk for death from suicide among women. Conclusions: Sociodemographic factors, health behaviors, and biological indicators were associated with risk of death from suicide among young adults. The main limitation of our study is that we did not have data on family history of suicide or previous experience of suicidal attempts. Future studies that elucidate the mechanisms behind the risk elevating effect of such factors are needed to further validate the findings from our study. Funding Statement: This study was supported by the Ministry of Health and Welfare of Korea (Grant No: 20170322652-00). Declaration of Interests: The authors of this paper, Yoosun Cho, Seulggie Choi, Kyuwoong Kim, and Sang Min Park, declare that we have no conflict of interest. Ethics Approval Statement: This study was approved by the Seoul National University Hospital Institutional Review Board (IRB number: 1703-039-836) and the requirement for informed consent was waived as the NHIS database is anonymized according to strict confidentiality guidelines.