Relationship between trauma center volume and outcomes.

CONTEXT: The premise underlying regionalization of trauma care is that larger volumes of trauma patients cared for in fewer institutions will lead to improved outcomes. However, whether a relationship exists between institutional volume and trauma outcomes remains unknown. OBJECTIVE: To evaluate the association between trauma center volume and outcomes of trauma patients. DESIGN: Retrospective cohort study. SETTING: Thirty-one academic level I or level II trauma centers across the United States participating in the University Healthsystem Consortium Trauma Benchmarking Study. PATIENTS: Consecutive patients with penetrating abdominal injury (PAI; n = 478) discharged between November 1, 1997, and July 31, 1998, or with multisystem blunt trauma (minimum of head injury and lower-extremity long-bone fractures; n = 541) discharged between June 1 and December 31, 1998. MAIN OUTCOME MEASURES: Inpatient mortality and hospital length of stay (LOS), comparing high-volume (>650 trauma admissions/y) and low-volume (