Performance of the New South Wales Ambulance Service major trauma transport protocol (T1) at an inner city trauma centre

Objective: To evaluate the performance of a newly implemented prehospital trauma triage (T1) protocol in New South Wales for patients transported to an inner city major trauma centre.

Methods: An observational study was conducted over 1 year. Prehospital data and injury characteristics were collected prospectively for all hospital trauma team activations and injury presentations transported by Ambulance Service of New South Wales. Univariate comparison of T1- and non-T1-transported patients was performed and sensitivity, specificity, overtriage and undertriage rates were calculated. The outcomes studied were Injury Severity Score >15 and major outcome (composite of in-hospital death and/or transferred from the ED to operating theatre or intensive care unit). Factors associated with undertriage were determined with univariate analysis.

Results: A total of 2664 ambulance arrivals for trauma were studied with 767(29%) transported on the T1 protocol. T1-transported patients were associated with more severe injury (23% vs 6%, P < 0.001) and major outcomes (30% vs 10%, P < 0.001) compared with non-T1-transported patients. The sensitivity of the T1 protocol for severe injury was 63% with a positive predictive value of 23%. The undertriage and overtriage rates for severe injury were 12% and 77%, respectively. Undertriaged patients were elderly with falls as the predominant mechanism of injury.

Conclusion: The sensitivity and undertriage rates associated with the T1 protocol indicate the ongoing need for secondary triage at designated trauma centres and refinement of the protocol to include age as a criterion.