Background: The use of helicopter emergency medical services (HEMS) for trauma patients has been debated since its introduction. We aim to compare outcomes for trauma patients transported by ground EMS (GEMS) vs. HEMS using raw and adjusted mortality in a level 1 trauma center.
Methods: A 6-year retrospective cohort study utilizing our level 1 trauma center registry for patients transferred by GEMS or HEMS was performed. Demographics and outcome measures were compared. Raw and adjusted mortality was evaluated. Adjusted mortality was determined incorporating confounders, including patient demographics, comorbid conditions, mechanism of injury, injury severity score (ISS), Glasgow Coma Scale score, and EMS transport time. Chi-square, multivariable logistic regression, and independent sample T-test were utilized with significance, defined as P < .05.
Results: Of 12 633 patients, 10 656 were transported via GEMS and 1977 with HEMS. Mean age was 55 for GEMS and 40 for HEMS (P < .001). Mean ISS was 9.29 and 11.73 for GEMS and HEMS (P < .001). Mean Revised Trauma Score was higher (less severe) for GEMS vs. HEMS (7.6 vs. 7.12, P < .001). Mean transport times for GEMS and HEMS was 39.45 vs. 47.29 minutes (P = .02). Raw mortality was 2.55% (307/10 656) for GEMS and 6.78% (134/1977) for HEMS. Adjusted mortality revealed a 16.6% increased mortality for GEMS compared to HEMS (adjusted odds ratio = 1.166, 95% CI: .815-1.668).
Conclusions: Air-lifted trauma patients were younger, more severely injured, and more hemodynamically unstable and required longer transport time but experienced lower adjusted mortality. Future research is needed to investigate whether reducing transport times and augmenting the advanced care already implemented by HEMS crews can improve outcomes.
Keywords: emergency medical services; observed/expected mortality; pre hospital trauma case; trauma outcomes; trauma systems.