Transport Mode and Trauma Triage Accuracy at a Level I Trauma Center

Trauma team activation criteria aim to minimize undertriage while limiting overtriage. Helicopter EMS (HEMS) may provide better prehospital information than ground EMS, but the impact of transport mode and activation pathway on triage performance is unclear.

A retrospective study of 18,183 scene trauma patients transported to a Level I trauma center was performed from January 2021 to December 2024. Transport mode was categorized as ground EMS, UT LIFESTAR HEMS, or other HEMS. UT LIFESTAR is an in-house HEMS program that self-determines trauma team activation; ground EMS and other HEMS report to a hospital triage nurse who assigns the activation level. Serious injury was defined as ISS > 15. Using a modified Cribari definition, high-level activation included full and partial activations. Undertriage was serious injury without high-level activation; overtriage as non-serious injury with high-level activation. We compared triage rates by mode and fit multivariable logistic models for undertriage (serious injuries only) and overtriage (activated patients only), adjusting for age, sex, and injury type; the undertriage model additionally adjusted for ISS.

Ground EMS accounted for 13,852 transports (76%), UT LIFESTAR 3,046 (17%) and other HEMS 1,285 (7%). Serious injury was more common in UT LIFESTAR (36%) and other HEMS (29%) than ground (19%, p<0.001). Undertriage rates were 26% for ground, 14% for other HEMS, and 5% for UT LIFESTAR (p < 0.001). In adjusted analysis of serious injuries (n=4,059), odds of undertriage were lower for UT LIFESTAR (OR 0.16, 95% CI 0.12–0.21) and other HEMS (OR 0.47, 95% CI 0.34–0.64) versus ground. Among high-level activations (n=11,809), overtriage rates were 76% for ground, 68% for other HEMS, and 63% for UT LIFESTAR (p < 0.01); adjusted odds of overtriage were lower for UT LIFESTAR (OR 0.53, 95% CI 0.49–0.59) and other HEMS (OR 0.67, 95% CI 0.58–0.78) versus ground.

External HEMS and our in-house self-activating HEMS demonstrated lower undertriage and overtriage than nurse-activated ground EMS, despite transporting more seriously injuried patients. These findings suggest that differences in prehospital assessment and communication, rather than activation pathway alone, drive triage performance and that HEMS-driven activation models may improve trauma triage and inform trauma system design.