Comparison of the revised Shock Index multiplied by the Glasgow Coma Scale and the Trauma and Injury Severity Score for predicting survival in paediatric patients with trauma: a nationwide retrospective cohort study in Japan

OBJECTIVES: The Trauma and Injury Severity Score (TRISS) is widely used to predict survival in patients with trauma; however, its predictive accuracy in paediatric populations remains suboptimal. In contrast, the revised Shock Index multiplied by the Glasgow Coma Scale (rSIG), a simple physiological marker, has shown potential utility in adults and children. Therefore, we aimed to compare the predictive performance of rSIG and TRISS in paediatric patients with trauma. DESIGN: Retrospective cohort study. SETTING: Japan Trauma Data Bank. PARTICIPANTS: Paediatric patients with trauma aged ≤17 years who were registered in the Japan Trauma Data Bank between 2009 and 2021. PRIMARY AND SECONDARY OUTCOME MEASURES: The optimal cut-off value for rSIG was determined using the derivation cohort (2009-2018). In the validation cohort (2019-2021), the predictive accuracy of rSIG and TRISS for in-hospital survival was compared using the area under the receiver operating characteristic curve (AUC). RESULTS: In the derivation cohort, the optimal cut-off value for rSIG was 10.13. In the validation cohort, the overall AUC for rSIG was 0.857 (95% CI 0.796 to 0.918) compared with 0.740 (95% CI 0.661 to 0.820) for TRISS, demonstrating the significantly superior predictive accuracy of rSIG (p=0.006). Age-stratified analyses revealed that rSIG significantly outperformed TRISS in the 7-12 and 13-17 age groups. CONCLUSIONS: The rSIG demonstrated higher predictive accuracy for in-hospital survival among paediatric patients with trauma than TRISS. These findings suggest that rSIG is a more effective prognostic tool for paediatric trauma care. Validation and the establishment of age-specific cut-off values are warranted to enhance its clinical applicability.