Validation of TRISS and ASCOT using a non-MTOS trauma registry.

OBJECTIVES: To validate the Trauma and Injury Severity Score (TRISS) and A Severity Characterization of Trauma (ASCOT) models for patients with blunt injuries using an independent trauma registry, and to develop new TRISS and ASCOT models for types of patients with blunt injuries and examine their fit.
DESIGN: Retrospective analysis of clinical data from the Institute for Trauma and Emergency Care (ITEC).
MATERIALS AND METHODS: Statistical models were developed using TRISS and ASCOT variables applied to ITEC data for patients with blunt injuries. These models were compared to Major Trauma Outcome Study (MTOS) models with regard to the resulting coefficients and hospital quality assessments. Also, separate models were developed for different groups of blunt injuries, and these models were compared with one another and tested for adequacy of fit.
MEASUREMENTS AND MAIN RESULTS: ASCOT performed acceptably well when new coefficients were derived using ITEC data, but TRISS did not. Although the models developed from MTOS and from ITEC coefficients generally yielded similar hospital quality assessments, there were some notable exceptions. Some TRISS and ASCOT variables were not significantly related to survival for some subgroups of blunt injuries, and neither the TRISS nor the ASCOT model was an adequate predictor of survival for patients suffering from low falls.
CONCLUSIONS: New TRISS and ASCOT coefficients should be derived if survival for patients with blunt injuries is to be predicted accurately in independent trauma registries. Also, it may be wise to consider developing separate models for subgroups of patients, particularly if hospitals in the registry have different mixes of patient types.