Predictive Performance of Trauma Scoring Systems for Mortality in Patients with High-Energy Trauma in the Emergency Department

Background/Objectives: Early identification of high-risk trauma patients is essential for optimizing clinical decision-making and improving outcomes. Several trauma scoring systems are available, but their comparative performance for predicting early and short-term mortality remains uncertain. This study compared the prognostic performance of the Injury Severity Score (ISS), Trauma and Injury Severity Score (TRISS), Rapid Emergency Medicine Score (REMS), and Shock Index for predicting both 24-h and 28-day mortality in patients with high-energy trauma. Methods: This prospective observational study included 277 consecutive adult patients presenting with high-energy trauma to a tertiary emergency department. ISS, TRISS, REMS, and Shock Index were calculated on admission. The primary outcomes were 24-h and 28-day mortality. Discriminatory performance was assessed using receiver operating characteristic (ROC) analysis. Optimal cut-off values were determined using the Youden index, and pairwise ROC comparisons were performed using the DeLong method. An exploratory multivariable logistic regression analysis was conducted to evaluate factors associated with 28-day mortality. Results: The 24-h mortality rate was 1.4% (4/277), whereas the 28-day mortality rate was 5.4% (15/277). For predicting 28-day mortality, TRISS (AUC 0.939, 95% CI 0.898–0.979), REMS (AUC 0.907, 95% CI 0.842–0.971), and ISS (AUC 0.900, 95% CI 0.827–0.973) demonstrated excellent and comparable discrimination, whereas Shock Index showed significantly lower predictive performance (AUC 0.696, 95% CI 0.519–0.874). Pairwise DeLong comparisons demonstrated no significant differences among ISS, TRISS, and REMS, whereas Shock Index performed significantly worse than all three scores. Exploratory multivariable analysis identified antiplatelet therapy, abdominal trauma, head and neck trauma, any comorbidity, and age ≥ 65 years as factors associated with increased odds of 28-day mortality. Conclusions: ISS, TRISS, and REMS demonstrated comparable and excellent performance for predicting 28-day mortality following high-energy trauma, whereas Shock Index showed significantly lower discriminatory ability. REMS may provide a practical bedside tool for early risk assessment, while ISS and TRISS remain valuable for comprehensive prognostic evaluation. Because of the limited number of mortality events, the multivariable analysis should be considered exploratory and requires validation in larger prospective multicenter studies.