Comparison of the Thoracic Trauma Severity Score (TTSS) and Trauma and Injury Severity Score (TRISS) in predicting clinical outcomes in chest trauma patients: protocol for a prospective cohort study from Iraq.

Background: Thoracic trauma significantly contributes to Iraq's trauma mortality. While the Thoracic Trauma Severity Score (TTSS) and the Trauma and Injury Severity Score (TRISS) are validated internationally, their effectiveness in low-resource settings like Iraq remains unclear. This study aims to address this critical gap by evaluating and comparing the predictive performance of both tools in predicting clinical outcomes. The findings of this study will lay the groundwork for developing a more suitable chest trauma scoring model tailored to this unique setting and similar environments with limited resources. Methods: Prospective cohort study that will recruit 195 adult chest trauma patients (blunt/penetrating) from March to December 2025. Based on standardized protocols, TTSS and TRISS scores will be calculated within 6 hours of admission. Primary outcome: in-hospital mortality. Secondary outcomes: intensive care unit (ICU) admission, morbidity, early hospital discharge, and surgical intervention. Predictive accuracy will be compared using ROC-AUC analysis and sensitivity/specificity. Discussion: TTSS is likely to demonstrate greater specificity for thoracic outcomes than TRISS. Possible limitations include resource-related constraints that lead to inappropriate ICU allocation and prehospital delays affecting physiological measures. If validated, TTSS may streamline emergency room triage across Iraq-utilizing scarce critical care resources more effectively. Further studies should be done to validate findings across the various trauma centers in Iraq and develop hybrid scoring models.