Background: Improved survival after injury has been demonstrated with trauma system implementation and designation of trauma centers. Local designating health authorities or national verification (United States) or accreditation (Canada) programs audit trauma center performance. The relative importance of designation versus accreditation with respect to improved outcomes is not clear. The purpose of this study was to measure outcomes within a single regional trauma system after designation of trauma centers and to compare outcomes in the one accredited center to the nonaccredited centers.
Methods: Data from three trauma centers were studied. All were large, university-affiliated regional medical centers, integrated into a regional trauma system and served by a single ambulance service. The study period was 1992 to 1999, immediately after trauma center designation in 1991. The British Columbia Trauma Registry was used to identify trauma patients, mechanism of injury, length of stay, case mix, case volume, acuity, pediatric caseload, and proportion of transfers at each center. A questionnaire was circulated to each hospital to determine the level of institutional support and programmatic development for trauma. The Trauma Registry was used to calculate z scores (TRISS methodology) for each center and TRISS-adjusted mortality odds ratios between institutions. Differences in covariables were controlled for in subgroup analysis.
Results: Two centers (hospitals A and C) had a high trauma caseload; one (hospital B) had a small and diminishing caseload. Only one center (hospital A) developed a trauma program consistent with Canadian accreditation criteria; z scores for center A were consistently better than at hospital B or C and survival odds ratios were significant. This finding applied to the total trauma population, blunt adult trauma patients (whether or not transfers and hip fracture patients were excluded), and in the more severely injured blunt trauma subgroups. There were no differences between hospitals for the relatively small number of patients with penetrating trauma.
Conclusion: Differences between hospitals were apparent from the outset of the trauma system. However, designation as a trauma center does not appear to necessarily improve survival in large regional medical centers. Development of a trauma program and commitment to meeting national guidelines through the accreditation process does appear to be associated with improved outcome after injury.