Abstract
BACKGROUND: Accurate early identification of bleeding trauma patients remains challenging. Several clinical prediction tools-including the Assessment of Blood Consumption (ABC) score, Trauma-Associated Severe Hemorrhage (TASH) score, and shock index (SI)-have been developed to guide transfusion decisions, but their performance across clinically meaningful outcomes remains uncertain. METHODS: We conducted a retrospective cohort study of trauma patients with massive hemorrhage protocol (MHP) activation at a university-affiliated, regional referral trauma center in Ontario, Canada, from July 2019 to September 2022. We included patients aged ≥ 16 years who presented within 3 h of injury. We evaluated the ABC score, TASH score, and SI for predicting massive transfusion (≥ 10 PRBCs in 24 h or ≥ 5 PRBCs in 4 h), the critical administration threshold (CAT; ≥3 PRBCs in 1 h), need for hemostatic intervention, and hemorrhage-related mortality. Score performance was assessed using area under the ROC curve (AUC), sensitivity, and specificity. RESULTS: Among 331 patients, 10.6% received ≥ 10 PRBCs, 20.8% met the 5-unit threshold, 30.8% met CAT, 27.8% required hemostatic intervention, and 4.2% died from hemorrhage during the index admission. The TASH score had the highest AUCs (0.72-0.82) but poor sensitivity. The ABC score showed moderate, threshold-dependent performance (AUCs 0.66-0.76). The shock index (≥ 1.0) showed fair discrimination for major transfusion thresholds (AUC ~ 0.74) but was less predictive for hemostatic intervention (AUC 0.60). CONCLUSION: The ABC, TASH, and SI scores performed poorly to moderately across key bleeding outcomes. These findings highlight the need for improved tools aligned with real-time, clinically actionable endpoints in trauma resuscitation.