Do inclusive trauma systems improve outcomes after renal trauma?

BACKGROUND: Our aim is to assess state variation in renal trauma outcomes. We hypothesize that states with more hospitals participating in a trauma system will have lower nephrectomy and mortality rates.
METHODS: The Healthcare Cost and Utilization Project State Inpatient Database was used to conduct a retrospective cohort study of all patients hospitalized with renal injury from partnering states during 2001, 2004, and 2007. State trauma systems were categorized based on the proportion of all acute care hospitals designated as a trauma center (Levels I-V) with higher proportions correlating to a more inclusive system. Poisson regression for relative risks (RRs) of inpatient nephrectomy and case fatality were performed adjusting for patient and state level factors.
RESULTS: Patients in states with the "most inclusive" trauma systems had a 30% lower risk of nephrectomy (RR, 0.70; 95% confidence interval [CI], 0.56-0.88) and a 2.06% lower unadjusted inpatient case fatality rate compared with states with "exclusive" trauma systems. Inpatient case fatality risk varied significantly by trauma system inclusiveness. Patients treated in states with either a "more inclusive" (RR, 0.85; 95% CI, 0.74-0.97) or "most inclusive" (RR, 0.74; 95% CI, 0.64-0.85) trauma system were independently associated with a lower inpatient case fatality risk compared with states with "exclusive" systems.
CONCLUSIONS: A reduced risk of nephrectomy and inpatient case fatality are more common among states that have a higher proportion of acute care hospitals participating as a trauma center (Levels I-V). Standardization of care may correlate with improved patient outcomes after renal trauma. LEVEL OF EVIDENCE: II, exploratory cohort analysis.