Sociodemographic Factors, Health Behaviors, and Biological Indicators Associated With Suicide Mortality Among Young Adults in South Korea: A Nationwide Cohort Study Among 15 Million Men and Women

Objective: 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 explore the association of these variables with the risk of death by suicide among young adults.

Methods: The study population consisted of 15,534,438 individuals aged 20-39 years from the Korean National Health Insurance Service. Sociodemographic factors associated with death by suicide during 2006-2015 were evaluated. 3,396,353 individuals who underwent health examinations between 2002 and 2005 were separately assessed for health behaviors and biological indicators associated with death by suicide. Cox proportional hazards regression analysis was used to determine the hazard ratios (HRs) and 95% confidence intervals (CIs) for suicide mortality according to sociodemographic factors (age, household income, job status, residence, and Charlson comorbidity index score), health behaviors (physical activity, smoking, and alcohol consumption), and biological indicators (blood pressure, total cholesterol level, body mass index, and fasting serum glucose level).

Results: Low household income, self- and non-employment, increased comorbidity, smoking, and normal weight elevated the risk of death by suicide among young adults. While older age was associated with elevated risk for death by suicide among men (adjusted HR [aHR] = 2.11; 95% CI, 2.02-2.20 for men aged 35-39 years), older age reduced the risk for death by suicide among women (aHR = 0.72; 95% CI, 0.69-0.75 for women aged 35-39 years). Elevated blood pressure and fasting serum glucose level were associated with increased risk for death by suicide among men (aHR = 1.16; 95% CI, 1.05-1.28 and aHR = 1.48; 95% CI, 1.26-1.75, respectively). Finally, high total cholesterol levels were associated with increased risk for death by suicide among women (aHR = 1.59; 95% CI, 1.19-2.13)

Conclusions: Sociodemographic factors, health behaviors, and biological indicators were associated with suicide mortality among young adults.