Aims, Objectives and Background In order to direct patients to specialist Major Trauma Centres (MTCs), triage is performed at the scene of an incident to evaluate the extent of a patient’s injuries. The most severely injured patients are then transported directly to an MTC, even if there is a closer ED. This process is known as ‘Trauma Unit Bypass’ (TUB) and decision support tools are provided for use by ambulance service providers. This study aims to evaluate a tool in current operational use and suggest amendments which may improve its performance in clinical practice.

Method and Design Data from a period of 12-months (1065 cases) were used to evaluate the performance of a TUB tool used in an English ambulance service. Data were sourced from the Trauma Audit and Research Network (TARN) and ED records and case reviews were performed to extract the required information. Statistical analysis was performed to evaluate the accuracy of the tool in identifying major trauma, defined as an Injury Severity Score (ISS) greater than 15. Further analysis was undertaken to make recommendations for alterations to the tool

Results and Conclusion The sensitivity of the Wessex TUB is 51.3% and the specificity is 71.3% which makes the tool a poor predictor of major trauma. The tool could be improved by altering thresholds for vital signs (blood pressure and Glasgow Coma Scale) and by providing clarity around the injury findings.

This study provides the first full evaluation of this tool in clinical practice and makes some recommendations to improve performance. This could lead to more accurate identification of patients who have suffered major trauma and ensure they are transported to an appropriate specialist centre. However, it was identified that ISS>15 may not be the most useful outcome measure and it is recommended that a new definition is developed which more accurately describes need for MTC input.