Performance Stability in Severe Traumatic Brain Injury Care Despite Increasing Patient Age and Severity: A 10-Year Outcome Analysis at a Regional Trauma Center

Background: The epidemiology of traumatic brain injury (TBI) is shifting toward an older population with greater clinical severity.This study evaluates the 10-year performance of a regional trauma center using conventional and modified survival prediction models to analyze these demographic changes.Methods: We retrospectively analyzed 3,697 patients with TBI admitted between 2016 and 2025.A subgroup analysis was performed for patients with severe TBI (n = 1,167), defined as an initial Glasgow Coma Scale score ≤ 8 and a Head Abbreviated Injury Scale score ≥ 4. Survival outcomes were evaluated using the conventional Trauma Score and Injury Severity Score (cTRISS) and modified Trauma Score and Injury Severity Score (mTRISS) models.Multivariable logistic regression was used to identify independent predictors of mortality.Results: The median age increased from 54.5 to 61.0 years (P = 0.008), and injury severity increased over the study period.Although crude mortality increased, the mean time to the operating room decreased from 1.83 to 1.25 hours (P = 0.035).In the severe TBI subgroup, the cTRISS model yielded a negative W score (-11.99).In contrast, the mTRISS model showed an observed-to-expected ratio of 0.739 and a W score of +19.30 (Z score 12.06, P < 0.001).Multivariable analysis confirmed that age (odds ratio, 1.032; P < 0.001) and injury severity were independent predictors of mortality; however, calendar year was not a significant independent predictor (P = 0.978), indicating stable institutional performance.Conclusion: Although crude mortality in TBI is increasing in parallel with population aging, our analysis using the mTRISS model demonstrates that meaningful survival benefits can be maintained through dedicated system optimization.Specifically, a full-time neurotrauma team and hyperacute triage protocols effectively offset the increasing baseline risks associated with an aging demographic.These findings suggest that integrated, specialized systems are essential for sustaining stable clinical performance amid shifting trauma epidemiology.