Level I versus Level II trauma centers: an outcomes-based assessment.

Objective: Trauma centers improve outcomes compared with nontrauma centers, although the relative benefit of different levels of major trauma centers (Level I vs. Level II hospitals) remains unclear. We sought to determine whether there was a difference in the patient outcome in trauma victims taken to Level I versus Level II trauma centers.

Methods: A multicenter, retrospective cohort analysis of all patients with trauma (>15 years), meeting State of Ohio trauma criteria, transported directly from the scene to a Level I or a Level II hospital (27 centers) between January 2003 and December 2006. Propensity score adjustment was used to adjust for nonrandom selection of hospital destination (I vs. II) and included age, emergency medical services (EMS) Glasgow Coma Score, comorbidities, EMS systolic blood pressure, injury type, injury severity, EMS procedures, emergency department procedures, gender, insurance status, and race. A propensity-adjusted multivariable logistic regression model was used to test the association between trauma center level and patient outcomes. Outcomes included in-hospital mortality and discharge destination (skilled nursing facility, rehabilitation center, home).

Results: A total of 18,103 patients were included in the analysis; 10,070 (56%) were transported to a Level I center. Patients taken to Level I centers had more severe injuries, more penetrating injuries, more complications, yet similar unadjusted mortality compared with Level II centers. In adjusted analyses, patients taken to Level I hospitals had improved survival compared with Level II centers (odds ratio [OR] 0.75, 95% confidence interval [CI] 0.56-0.98). Similar results were seen when restricting the analyses to patients with serious injuries (Injury Severity Score > 15; EMS Glasgow Coma Score < 9). Patients treated at Level I hospitals were more likely to be discharged home (OR 1.14, 95% CI 1.05-1.25), or a rehabilitation center or skilled nursing facility (OR 1.39, 95% CI 1.27-1.52).

Conclusions: Patients taken to Level I centers had improved survival and better functional outcomes compared with injured persons taken to Level II hospitals.