Accuracy of major trauma triage using the MATTS tool: a cohort study

INTRODUCTION: The Major Trauma Triage Study ('MATTS') triage tool was designed to identify patients with major trauma who could benefit from expedited care in specialist major trauma centres (MTCs). We aimed to investigate the impact of the MATTS tool on major trauma triage decisions after implementation. METHODS: Consecutive patients were included in a multicentre, prospective cohort study conducted between 1 November 2021 and 15 May 2022 in six trauma networks served by West Midlands and Yorkshire Ambulance Services. Electronic data from ambulance service patient report forms were linked to data from the Trauma Audit and Research Network trauma registry. The accuracy of prehospital triage decisions (conveyance to an MTC with pre-alert) against a bespoke MATTS reference standard to define major trauma was calculated. This was compared with optimal undertriage/overtriage trade-off indicated by previous economic modelling. Additional analyses investigated theoretical triage tool accuracy based on recorded data irrespective of hospital destination, examined important injury subgroups, evaluated alternative reference standards and described triage tool use. RESULTS: In total, 38 010 injured patients were included, with 2.2% prevalence of major trauma. The MATTS triage tool demonstrated 55.3% sensitivity (95% CI 51.8% to 58.7%) and 94.3% specificity (95% CI 94.1% to 94.6%). There was evidence of triage tool use in a minority of patients (6.3%), with senior clinical advice sought in 9.3% of patients. Theoretical triage tool sensitivity was 51.1% (95% CI 47.6% to 54.5%) with specificity 93.6% (95% CI 92.7% to 94.4%). Agreement between the theoretical triage tool result and the observed triage decision was good (absolute agreement 90.4%, Gwet's agreement coefficient 1 (AC1) statistic 0.89, 95% CI 0.89 to 0.89). Accuracy varied across different ages, mechanisms of injury subgroups and alternative reference standards for major trauma. CONCLUSIONS: The MATTS triage tool achieved an appropriate undertriage/overtriage trade-off compared with previously established targets. However, documented adherence to MATTS was low. Dedicated training and further evaluation are necessary prior to national wider implementation.