Increased risk of suicide among individuals with chronic obstructive pulmonary disease: A nationwide cohort study in Korea

Abstract

Background: Previous studies have established that individuals with chronic obstructive pulmonary disease (COPD) have an increased risk of suicidal behaviors. However, it is uncertain which subgroups of individuals with COPD are at higher risk of suicide. Method: We analyzed data from the Korean National Health Insurance Service. The exposure was COPD, and the outcome was death by suicide. Participants were followed until their date of death by suicide, the censoring date, or December 31, 2021, whichever came first. A Fine-Gray proportional hazards model for subdistribution was used to determine the associations between COPD and death by suicide. Results: During a median follow-up of 11.3 years (interquartile range, 11.1–11.6 years), individuals with COPD had an increased risk of death by suicide compared to those without (adjusted subdistribution hazard ratio [aSHR] = 1.20, 95 % confidence interval [CI] = 1.08–1.32). When stratified by the presence or absence of potential risk factors and COPD, the risk of suicide was highest in the COPD population with current smoking habits ≥20 PY (aSHR = 1.71, 95 % CI = 1.39–2.12), depression (aSHR = 2.46, 95 % CI = 1.97–3.08), and anxiety (aSHR = 2.71, 95 % CI = 1.87–3.92) compared to their corresponding reference groups (non-COPD population without the corresponding potential risk factors). Conclusions: COPD increased the risk of death by suicide. This risk was particularly pronounced when current heavy smoking habits, depression, and anxiety coexisted with COPD.