Survival of the fittest: the hidden cost of undertriage of major trauma.

BACKGROUND Injured patients cared for in trauma centers have a lower risk of death than those cared for in nontrauma centers. However, many patients are transported to a non-trauma center after injury (undertriaged) and require transfer to trauma center care. Previous analyses of undertriage focused only on survivors to trauma center care and were potentially subject to survivor bias. Using a novel population-based design, we evaluated the true mortality cost of undertriage. STUDY DESIGN We used a retrospective cohort design and included all severely injured patients surviving to reach an emergency department within the province of Ontario, Canada. Those patients who were triaged to a non-trauma center as their first hospital exposure were the Undertriage cohort. Undertriage cohort patients were either transferred to a trauma center (Transfer cohort) or died before transfer could be accomplished (emergency department-death cohort). Patients that were transported directly from the scene of injury to a trauma center represented the Direct cohort. Thirty-day mortality in undertriaged patients was analyzed using two approaches: allowing for survivor bias (Transfer versus Direct) and without survivor bias (Undertriage versus Direct). RESULTS Among 11,398 patients, 66% were transported directly to a trauma center and 30% were transferred. Four percent died before transfer (22% of all deaths). Reproducing approaches that ignore survivor bias, mortality in the Transfer and Direct cohorts was equivalent. However, unbiased assessment demonstrated that mortality was significantly higher in the Undertriage cohort than the Direct cohort (odds ratio = 1.24; 95% CI, 1.10-1.40). CONCLUSIONS Undertriage after major trauma is associated with substantial mortality. These data suggest a need to design strategies to improve triage to trauma center.