Incidence and mortality of severe trauma in South Korea: A nationwide registry-based cohort study, 2016 to 2024.

Severe trauma is a leading cause of mortality worldwide; however, contemporary data on mechanism-specific incidence trends and factors associated with in-hospital mortality remain limited. We conducted a nationwide cohort study using a South Korean severe trauma registry spanning 2016 to 2024. Severe trauma was defined as an Injury Severity Score (ISS) ≥ 16. Annual incidence trends were assessed using negative binomial regression with incidence rate ratios (IRRs) and 95% confidence intervals (CIs). Factors associated with in-hospital mortality were identified using multivariable logistic regression, performed separately for patients with and without prehospital cardiac arrest. A total of 73,232 patients were included, of whom 44.9% had prehospital cardiac arrest. Overall in-hospital mortality was 58.2% (26.0% vs 97.7% for patients without versus with prehospital cardiac arrest, respectively). Transport-related injuries were the most common (53.5%), followed by falls/slips (38.2%). Transport-related severe trauma declined by 3.6% annually (IRR, 0.964; 95% CI, 0.955-0.974; P < .001), whereas falls/slips increased by 3.7% annually (IRR, 1.037; 95% CI, 1.024-1.050; P < .001). Among patients without prehospital cardiac arrest, higher ISS (ISS 25-40: adjusted odds ratio [aOR], 3.45; 95% CI, 3.26-3.64; ISS 41-75: aOR, 6.12; 95% CI, 5.40-6.93) and older age (≥65 years: aOR, 2.87; 95% CI, 2.16-3.84) were the strongest independent predictors of in-hospital mortality. Male sex, unintentional injury, lower-level receiving emergency departments, and falls/slips as the injury mechanism (aOR, 1.19; 95% CI, 1.13-1.26) were also independently associated with increased mortality. Among patients with prehospital cardiac arrest, conventional trauma system factors lost prognostic significance; self-harm was the strongest independent predictor (aOR, 2.14; 95% CI, 1.53-3.08). Female sex and injury in nonmetropolitan areas were also independently associated with increased mortality. The epidemiology of severe trauma in South Korea is evolving, with transport-related injuries declining and falls/slips increasing. Preventive strategies for falls/slips should become a public health priority. Given the near-universal mortality among patients with prehospital cardiac arrest, in whom conventional trauma system factors lose prognostic significance, primary prevention strategies, including suicide prevention and injury awareness programs, may yield greater reductions in severe trauma mortality than trauma system development alone.