Comparative Validation of Five Early Trauma Scores for 24-Hour In-Hospital Mortality in Traumatic Brain Injury

Background Early risk stratification after traumatic brain injury (TBI) is crucial to guide monitoring, escalation of care, and interfacility transfer within the first hours. Bedside scores (RTS, GAP, mREMS, MGAP, MEWS) are simple and widely available, yet their comparative accuracy for predicting 24-hour in-hospital mortality in TBI remains uncertain. Prior studies often use mixed trauma cohorts, later endpoints, and provide limited evaluation of calibration or threshold-level clinical utility. TBI-specific head-to-head evidence is therefore needed. Methods This study analyzed consecutive traumatic brain injury admissions in 2024 at a tertiary medical center in Nantong, China (n = 2,287; 24-hour mortality 7.3%). Five bedside scores (RTS, GAP, mREMS, MGAP, MEWS) were recalibrated with a single logistic equation, and performance (AUROC, AUPRC, Brier score, calibration intercept and slope) and clinical utility (net benefit per 100 patients at 10% and 20% thresholds) were estimated with 95% confidence intervals from 1,000 bootstrap resamples; precision–recall curves were referenced to the cohort prevalence. Results RTS and GAP showed the strongest discrimination, with mREMS close. AUROC: RTS 0.874 (95% CI 0.841–0.903), GAP 0.863 (0.831–0.898), mREMS 0.856 (0.826–0.883); MGAP and MEWS were lower (0.632, 0.606). AUPRCs were 0.465 (0.381–0.531) for RTS, 0.382 (0.308–0.453) for GAP, and 0.370 (0.280–0.424) for mREMS (MGAP 0.154 (0.112–0.199); MEWS 0.129 (0.098–0.159)). Brier scores were 0.050, 0.053, and 0.055 for RTS, GAP, and mREMS, respectively. After simple logistic recalibration, calibration intercepts were near 0 and slopes near 1, with observed-vs-predicted curves close to the 45° line across deciles. At 10% and 20% thresholds, RTS and GAP achieved the highest net benefit and more favorable trade-offs per 100 patients; mREMS was intermediate. Conclusion RTS and GAP showed the best balance of discrimination, calibration, and net benefit at 10% and 20% thresholds; mREMS was comparable after simple recalibration. These findings support prioritizing RTS and GAP for early TBI risk stratification.