Impact of Trauma Center Designation on Outcomes: Is There a Difference Between Level I and Level II Trauma Centers?

BACKGROUND: Within organized trauma systems, both Level I and Level II trauma centers are expected to have the resources to treat patients with major multisystem trauma. The evidence supporting separate designations for Level I and Level II trauma centers is inconclusive. The objective of this study was to compare mortality and complications for injured patients admitted to Level I and Level II trauma centers. STUDY DESIGN: Using data from the Pennsylvania Trauma Outcomes Study registry, we performed a retrospective observational study of 208,866 patients admitted to 28 Level I and Level II trauma centers between 2000 and 2009. Regression modeling was used to estimate the association between patient outcomes and trauma center designation, after controlling for injury severity, mechanism of injury, transfer status, and physiology. RESULTS: Patients admitted to Level I trauma centers had a 15% lower odds of mortality (adjusted odds ratio [adj OR] 0.85; 95% CI 0.72 to 0.99) and a 35% increased odds of complications (adj OR 1.37; 95% CI 1.04 to 1.79). The survival benefit associated with admission to Level I centers was strongest in patients with very severe injuries (Injury Severity Score [ISS] ≥ 25; adj OR 0.78; 95% CI 0.64 to 0.95). Less severely injured patients with an ISS < 9 (adj OR 0.91; 95% CI 0.64 to 1.30) and with an ISS between 9 and 15 (adj OR 0.98; 95% CI 0.81 to 1.18) had similar risks of mortality in Level I and Level II trauma centers. CONCLUSIONS: Severely injured patients admitted to Level I trauma centers have a lower risk of mortality compared with patients admitted to Level II centers. These findings support the continuation of a 2-tiered designation system for trauma.