Abstract
BACKGROUND: Traumatic brain injury (TBI) is a major cause of trauma-related morbidity and mortality worldwide. Early identification of patients at risk of clinical deterioration is essential for optimizing emergency management. The Modified Early Warning Score (MEWS) and the reverse Shock Index multiplied by the Glasgow Coma Scale (rSIG) are simple, rapidly calculable tools that may assist clinicians in early prognostic assessment. This study aimed to evaluate the prognostic performance of MEWS and rSIG in predicting poor outcomes among patients with isolated head trauma. METHODS: This retrospective observational study included patients presenting to the emergency department of Manisa Celal Bayar University Hospital between June 2021 and June 2024 with isolated head trauma. Demographic, clinical, and laboratory data were retrieved from the hospital information system. MEWS, Shock Index (SI), reverse Shock Index (rSI), and rSIG values were calculated for each patient. Group comparisons were performed using nonparametric tests. Correlations were analyzed using Spearman coefficients. Receiver operating characteristic (ROC) curves were constructed to assess discriminative power, and binary logistic regression was used to identify independent predictors of poor outcomes, defined as intensive care unit admission and/or in-hospital mortality. RESULTS: A total of 705 patients (65.7% male; mean age 37.2+-27.0 years) were analyzed. Pathological cranial CT findings were present in 24.7%, and the overall mortality rate was 2.7%. Patients with poor outcomes exhibited significantly higher MEWS and SI values, whereas GCS, rSI, and rSIG were markedly lower (all p <0.001). ROC analysis showed moderate predictive ability for rSIG (AUC=0.701) and limited discriminative power for MEWS (AUC=0.610), with optimal cut-offs of ≤21.35 and ≥0.5, respectively. In multivariate analyses, MEWS and rSIG demonstrated independent prognostic significance for poor outcomes in separate models, with rSIG remaining significant in models excluding GCS. MEWS correlated positively with hospital stay (r=0.385, p<0.001), while rSIG showed a negative correlation (r=-0.252, p<0.001). CONCLUSION: MEWS and rSIG are practical bedside tools that may support early risk stratification in patients with isolated head trauma. MEWS reflects early physiological deterioration, while rSIG provides complementary hemodynamic-neurological information and should be interpreted as an adjunct rather than a standalone triage instrument. Routine use of these scores may support early clinical decision-making and patient monitoring in the emergency setting when interpreted as adjuncts to standard clinical assessment.