Background: Survival and discharge status from severe traumatic brain injury (TBI) patients treated during the past 11 years in seven state-designated Level I trauma centers was analyzed to test for a relationship between patient volume and outcome.
Methods: Data for patients age 16 years to 64 years were aggregated by quarter for years 2000 to 2010. TBI patients were identified using DRG International Classification of Diseases--9th Rev.--Clinical Modification codes: 800 to 804 and 850.1 to 854. Severity was defined using the International Classification Injury Severity Score (ICISS) less than 0.85 (risk of death > 15%). Using a random effects model controlling for sex, race, ethnicity, and insurance status, TBI volume was analyzed against quarterly inpatient mortality and functional recovery, defined as discharge to home or rehabilitation versus transfer to skilled nursing facilities. Hospitals were categorized into quarterly TBI volume quintiles, using the top quintile (highest-volume center) as control. To account for overall injury severity influence, ICISS was further categorized as less than 20%, 20% to 40%, and 40% to 60%.
Results: Two high-volume hospitals consistently treated more TBI patients (>40 patients per quarter). Four treated less than 40 patients per quarter, and one transitioned to high-volume midway through the study period. After controlling for severity, demographics, and insurance status, highest-volume centers demonstrated a 9% lower mortality risk (p < 0.001). Lower-volume hospitals discharged a significantly larger proportion of TBI patients to skilled nursing facilities and fewer patients to home or rehabilitation facilities (p < 0.01).
Conclusion: High volume (>40 patients per quarter) is associated with improved severe TBI patient survival and, probably, improved quality of life. Efforts to identify best practices and implement educational interventions to improve compliance with best-practice standards will benefit patients with severe traumatic brain injury.
Level of evidence: Epidemiologic study, level III.