The effect of trauma center designation and trauma volume on outcome in specific severe injuries

Objective: The objective of this study was to investigate the effect of American College of Surgeons (ACS) trauma center designation and trauma volume on outcome in patients with specific severe injuries. Background: Trauma centers are designated by the ACS into different levels on the basis of resources, trauma volume, and educational and research commitment. The criteria for trauma center designation are arbitrary and have never been validated. Methods: The National Trauma Data Bank study, which included patients > 14 years of age and had injury severity score (ISS) > 15, were alive on admission and had at least one of the following severe injuries: aortic, vena cava, iliac vessels, cardiac, grade IV/V liver injuries, quadriplegia, or complex pelvic fractures. Outcomes (mortality, intensive care unit stay, and severe disability at discharge) were compared among level I and 11 trauma centers and between centers within the same level designation but different volumes of severe trauma (< 240 vs >= 240 trauma admissions with ISS > 15 per year). The outcomes were adjusted for age (< 65 >= 65), gender, mechanism of injury, hypotension on admission, and ISS (<= 25 and > 25). Results: A total of 12,254 patients met the inclusion criteria. Overall, level I centers had significantly lower mortality (25.3% vs 29.3%; adjusted odds ratio [OR], 0.81; 95% confidence interval [CI], 0.71-0.94; P = 0.004) and significantly lower severe disability at discharge (20.3% vs 33.8%, adjusted OR, 0.55; 95% Cl, 0.44-0.69; P < 0.001) than level II centers. Subgroup analysis showed that cardiovascular injuries (N = 2004) and grades IV-V liver injuries (N = 1415) had a significantly better survival in level I than level II trauma centers (adjusted P = 0.017 and 0.023, respectively). Overall, there was a significantly better functional outcome in level I centers (adjusted P < 0.001). Subgroup analysis showed level I centers had significantly better functional outcomes in complex pelvic fractures (P < 0.001) and a trend toward better outcomes in the rest of the subgroups. The volume of trauma admissions with ISS > 15 (< 240 vs >= 240 cases per year) had no effect on outcome in either level I or I centers. Conclusions: Level I trauma centers have better outcomes than lower-level centers in patients with specific injuries associated with high mortality and poor functional outcomes. The volume of major trauma admissions does not influence outcome in either level I or II centers. These findings may have significant implications in the planning of trauma systems and the billing of services according to level of accreditation.