Significant variations in mortality occur at similarly designated trauma centers.

HYPOTHESIS: Mortality rates vary across designated trauma centers (TC), even after controlling for injury severity.
DESIGN: Retrospective analysis of state trauma registry data.
SETTING: Designated Level 1 and 2 TCs in 2003 in a large Southwestern state. PATIENTS: Adult trauma patients (n = 18,584) treated at 15 designated Level 1 and 2 TCs. MAIN OUTCOME MEASURES: Risk-adjusted survival was calculated for each trauma center using logistic regression analysis to adjust for differences in age, sex, race, injury mechanism, and injury severity. The model was developed using half of the study population and validated in the remaining half. It was then applied to the entire study population, with inclusion of TC identification codes. Observed vs Expected survival ratios were then calculated for each TC. Adjusted odds ratios (OR) for survival at each TC were also calculated.
RESULTS: Adjusted OR of survival were significantly different from crude OR at 6 of the 14 TCs, underscoring the importance of risk adjustment when performing quality comparisons. One TC performed significantly worse than the others, 8 achieved significantly better survival, and 5 performed the same as the referent. Observed vs Expected ratios demonstrated that one trauma center had significantly worse severity-adjusted outcomes, some were marginal, some performed as well as expected, and none performed better than expectations.
CONCLUSIONS: Considerable variations in risk-adjusted mortality rates exist across similarly designated TCs. Such variability in outcomes may reflect variations in quality of care, and reasons for this discrepancy should be explored as the next step in the trauma care quality improvement process.