Performance evaluation and validation of the animal trauma triage score and modified Glasgow Coma Scale with suggested category adjustment in dogs: A VetCOT registry study.

Abstract

To examine the animal trauma triage (ATT) and modified Glasgow Coma Scale (mGCS) scores as predictors of mortality outcome (death or euthanasia) in injured dogs. Observational cohort study conducted from September 2013 to March 2015 with follow-up until death or hospital discharge. Nine veterinary hospitals including private referral and veterinary teaching hospitals. Consecutive sample of 3,599 dogs with complete data entries recruited into the Veterinary Committee on Trauma patient registry. None. We compared the predictive power (area under receiver operating characteristic [AUROC]) and calibration of the ATT and mGCS scores to their components. Overall mortality risk was 7.3% (n = 264). Incidence of head trauma was 9.5% (n = 341). The ATT score showed a linear relationship with mortality risk. Discriminatory performance of the ATT score was excellent with AUROC = 0.92 (95% confidence interval [CI] 0.91 to 0.94) and pseudo R2 = 0.42. Each ATT score increase of 1 point was associated with an increase in mortality odds of 2.07 (95% CI = 1.94-2.21, P<0.001). The "eye/muscle/integument" category of the ATT showed poor discrimination (AUROC = 0.55). When this component together with the skeletal and cardiac components were omitted from calculation of the overall score, there was no loss in discriminatory capacity (AUROC = 0.92 vs 0.91, P = 0.09) compared with the full score. The mGCS showed good performance overall, but performance improved when restricted to head trauma patients (AUROC = 0.84, 95% CI = 0.79-0.90, n = 341 vs 0.82, 95% CI = 0.79-0.85, n = 3599). The motor component of the mGCS showed the best predictive performance (AUROC = 0.79 vs 0.66/0.69); however, the full score performed better than the motor component alone (P = 0.002). When assessment was restricted to patients with head injury (n = 341), the ATT score still performed better than the mGCS (AUROC = 0.90 vs 0.84, P = 0.04). In external validation on a large, multicenter dataset, the ATT score showed excellent discrimination and calibration; however, a more parsimonious score calculated on only the perfusion, respiratory, and neurological categories showed equivalent performance.