Costs of Transfer From Nontrauma to Trauma Centers Among Patients With Minor Injuries.

Importance: Nearly half the patients transferred from nontrauma centers to trauma centers have minor injuries, yet trauma center care is not associated with a difference in morality among patients with minor injuries. Consequently, reducing the frequency of such transfers has been postulated as a method to improve resource allocation. Currently, the economic implications of these transfers are not well understood. Objective: To estimate health care costs associated with the transfer of patients with minor injuries from nontrauma to trauma centers. Design, Setting, and Participants: This retrospective, population-based cohort study was conducted from April 1, 2009, to March 31, 2020, in Ontario, Canada. Participants included individuals aged 16 years or older who were transferred to a trauma center after presenting to a nontrauma center with a minor injury (survival >24 hours, Injury Severity Score [ISS] <16, and absence of an American College of Surgeons-defined critical injury). Statistical analysis was conducted from March 2022 to June 2024. Main Outcomes and Measures: The main outcome was total health care costs within 30 days of injury, standardized to 2015 Canadian dollars (CAD$). Propensity scoring was used to match transferred patients with controls admitted to nontrauma centers. Negative binomial models were used to estimate differences in costs between transferred patients and matched controls. Results: Of the 14 557 patients with minor injuries transferred to a trauma center (mean [SD] age, 48.1 [20.9] years; 5367 female patients [36.9%]; median ISS, 4 [IQR, 2-5]), 12 652 (86.9%) were matched with a control. Thirty days after injury, mean health care costs among transferred patients were CAD$13 540 (95% CI, CAD$13 319-CAD$13 765), a 6.5% (95% CI, 4.4%-8.5%) increase relative to controls (CAD$12 719 [95% CI, CAD$12 582-CAD$12 857]). Half the transferred patients (54.9% [7994 of 14 557]) were admitted, while the remainder were discharged after evaluation in the trauma center emergency department. Among patients admitted to a trauma center, mean 30-day costs were CAD$19 602 (95% CI, CAD$19 294-CAD$19 915), a 54.6% (95% CI, 51.5%-57.8%) increase relative to controls. Conclusions and Relevance: This cohort study of patients with minor injuries transferred from nontrauma centers to trauma centers found that the transfer of these patients was associated with increased costs to the health care system. Given the high prevalence of such transfers, these findings suggest that the development of systems to support the care of patients with minor injuries at their local hospitals is essential to the sustainability of trauma systems.