Refining the trauma triage algorithm at an Australian major trauma centre: derivation and internal validation of a triage risk score.

Abstract

To derive and internally validate a clinical prediction rule for trauma triage. Ambulance presentations requiring trauma team activation between 2007 and 2011 at a single inner city major trauma centre were analysed. The primary outcome was major trauma, defined as Injury Severity Score >15, intensive care unit admission or in-hospital death. Demographic details, vital signs on arrival at hospital, mechanism of injury and injured body regions were used in the modelling process. Multivariable logistic regression was used on a randomly selected derivation sample. Receiver operating characteristic (ROC) analysis and Hosmer-Lemeshow tests were used to assess the discrimination and calibration of the derived model. The model was further tested using bootstrapping cross-validation. A total of 3027 patients were identified. Predictors selected for the prediction model were age ≥65years (OR 1.58, 95%CI 1.08-2.32, p=0.02), abnormal vital signs (OR 3.72, 95%CI 2.64-5.25), Glasgow Coma Scale score ≤13 (OR 14, 95%CI 9.23-23.34 p<0.001), penetrating injury (OR 5.13, 95%CI 2.76-9.54, p<0.001), multiregion injury (OR 4.72 95%CI 3.45-6.46, p<0.001), falls (OR 1.51 95%CI 1.06-2.15, p=0.02) and motor vehicle crashes (OR 0.56, 95%CI 0.35-0.90, p=0.02). The ROC area under the curve (AUC) for the final model was 0.85 (95%CI 0.83-0.87) with a Hosmer-Lemeshow test statistic p=0.83. Bootstrapping cross-validation demonstrated an identical AUC. We have derived and internally validated a trauma risk prediction rule using trauma registry data. This may assist with the formulation of revised local and regional trauma triage protocols. External validation is required before implementation.