Interfacility Transfer is Associated With Lower Mortality in Undertriaged Gunshot Wound Patients.

BACKGROUND: Treatment at a Level I trauma center yields better outcomes for patients with moderate-to-severe injury as compared with treatment in nontrauma centers. We examined the association between interfacility transfer to a level I or II trauma center and mortality for gunshot wound patients, among patients initially transported to a lower level or undesignated facility. MATERIALS AND METHODS: This retrospective cohort study included all patients from the National Trauma Data Bank (2010-2015) with firearm as the external cause of injury, who met CDC criteria for emergency medical services triage to a higher level (American College of Surgeons [ACS] Level II or above) trauma center. We compared outcomes between patients (a) treated in an ACS level III or below facility and not transferred versus (b) transferred to an ACS level II or above facility, adjusting for confounders using inverse probability of treatment weights. RESULTS: Of the total 62,277 patients, 10,968 (17.6%) were transferred to a level II center or above, and 51,309 (82.4%) were treated at a level III or below or undesignated center. In adjusted analysis comparing transferred versus not transferred patients, risk was lower for mortality (risk ratio [RR] 0.81, 95% confidence interval [CI] 0.70 to 0.95 P = 0.011) but similar for any complication (RR 1.02, 95% CI 0.83 to 1.25 P = 0.87) and the five most common complications. Results were consistent when accounting for data missing at random, and when including state trauma center designations in the definition of Level II or greater versus III and below. CONCLUSIONS: Our study found lower mortality but similar complication risk associated with interfacility transfer for undertriaged gunshot wound patients. This suggests that transfer to a higher level center is warranted among these patients, with improved care potentially outweighing potential harms because of transfer.