M. Abid1, S. J. An1, A. Schneider1, J. Gallaher1, A. Charles1 1University Of North Carolina At Chapel Hill, Department Of Surgery, Chapel Hill, NC, USA
Introduction:
The worsening rates of suicide-related mortality in the U.S. have prompted renewed attention to this pressing public health issue. There are ongoing efforts to characterize the epidemiology of self-inflicted traumatic injury and death. This study compares the outcomes of trauma patients injured by assault to those injured by self-inflicted injury.
Methods:
We performed a propensity-matched retrospective analysis of patients with self-inflicted injuries ≥ 18 years presenting to a hospital in the National Trauma Data Bank from 2007-2021. Demographic and clinical information were collected. Outcomes were compared between patients with self-inflicted and assault injuries. The primary outcome was death. Secondary outcomes were hospital and intensive care unit (ICU) length of stay.
Results:
A total of 1,419,800 patients were included; 173,161 (12.2%) presented after self-inflicted injuries. The mean age in the self-injury group was 40.3 (SD 16.0) years, compared to the assault group at 34.9 (SD 13.2) years (p<0.01). The self-injury cohort had a higher proportion of females (24.3% versus 15.0% in the assault cohort, p<0.01) and higher severity of injury at presentation, with a mean Injury Severity Score (ISS) score of 11.4 (SD 12.6) compared to a mean ISS of 9.0 (SD 9.6) in the assault cohort (p<0.01). The most common type of injury in both groups was penetrating trauma, and the self-injury group had a higher proportion (81.5% compared to 58.2% in the assault group, p<0.01). The crude mortality rate was 18.9% in the self-inflicted injury group and 5.4% in the assault group (p<0.01). After propensity matching for age, sex, race, insurance categories, Charlson Comorbidity score, ISS, shock index, mechanism of injury, and time from scene to hospital, patients with self-inflicted injuries had 1.79 times higher odds of mortality (95% confidence interval [CI] 1.66, 1.93) and have longer hospital length of stay by 2.83 days (95% CI 2.46, 3.20).
Conclusions:
Compared to assaults, self-inflicted injuries confer an increased risk of mortality. Ongoing efforts to identify factors contributing to this mortality disparity will be critical to reducing suicides.