Abstract
IMPORTANCE: Previous studies suggest that critically injured patients are at increased risk of suicide following discharge, but these have mainly been single-center studies or had limited data on comorbidities and socioeconomic factors. OBJECTIVE: To examine the risk of suicide after hospitalization for traumatic injuries. DESIGN, SETTING, AND PARTICIPANTS: This nationwide register-based cohort study used data from 5 Norwegian nationwide health registries and Statistics Norway between 2014 and 2020. Patients registered in the Norwegian Trauma Registry (NTR) for whom trauma team activation at hospital arrival was mandated by national guidelines between 2015 and 2018 were matched to general-population controls on gender and birth year in a 1:10 ratio according to a matched cohort design. Patients discharged alive were followed-up for a minimum of 2 years. All Norwegian hospitals treating patients with traumatic injuries provide data to the NTR. The final analysis was conducted in April 2025. EXPOSURES: Traumatic injury, admitted to hospital, and registered in the NTR. MAIN OUTCOMES AND MEASURES: The outcome of interest was suicide, as registered in the Norwegian Cause of Death Registry. Cumulative incidence ratios (CIR) of suicide with 95% CIs, taking nonsuicidal death as a competing event into account, were estimated. Adjustments for Charlson Comorbidity Index, previous psychiatric illness, and socioeconomic position (SEP) were conducted using inverse probability of treatment weights. RESULTS: A total of 25 536 patients with traumatic injuries (165 897 [67%] male; mean [SD] age, 41 [23] years) were matched to 247 095 controls, with a mean (SD) age of 41 (23) years and 68% male. The cumulative incidences of suicide were 0.18% at 2 years and 0.34% and 5 years for patients with traumatic injuries and 0.02% at 2 years and 0.05% at 5 years for controls (2-year CIR, 9.3 [95% CI, 5.4-13.0]; 5-year CIR, 6.9 [95% CI, 4.4-9.1]). Patients with traumatic injury were older at the age of suicide compared with controls (mean [SD] age, 43 [19] years vs 36 [17] years; P = .03) and female patients with traumatic injury had higher incidence of suicide compared with female controls (36% vs 17%; P = .005). CONCLUSIONS AND RELEVANCE: In this cohort study of patients in Norway discharged alive after critical injury, a 9-fold increased risk of suicide after 2 years was observed. These findings suggest that follow-up is warranted for possible psychological distress in this patient group.