title: The volume-outcomes relationship for United States Level I trauma centers.
abstract: BACKGROUND
  Previous studies of the center volume-outcomes relationship for severe trauma care have yielded conflicting findings regarding the presence or nature of such a relationship. Few studies have confined their analysis to Level I centers.
  
  
  METHODS
  We performed a retrospective analysis of severely injured adults treated from 2001 through 2006 in United States Level I trauma centers using data from the National Trauma Data Bank version 7.1. The post-injury in-hospital mortality rates for patients treated at high- or medium-volume Level I trauma centers were compared with the rates for patients treated at low-volume Level I centers before and after adjustment for patient demographic and injury characteristics. Subgroup comparisons were performed for those Level I centers with and without American College of Surgeons (ACS) verification of Level I designation.
  
  
  RESULTS
  Overall, medium-volume Level I trauma centers had significantly lower mortality than low-volume centers (14.3% versus 15.6%), both before and after adjustment for patient demographic and injury characteristics. Of those trauma centers without ACS verification of Level I designation, high-volume centers had significantly greater mortality than low-volume centers.
  
  
  CONCLUSIONS
  Our findings support the current utilization by the American College of Surgeons of minimum annual volume requirements for the verification of Level I trauma center designation, and suggest that the presence of such verification may enable Level I centers to effectively manage high volume of severely injured adult patients.
authors.affiliation: Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: Kyla M
authors.initials: KM
authors.lastname: Bennett
authors.forename: Steven
authors.initials: S
authors.lastname: Vaslef
authors.forename: Theodore N
authors.initials: TN
authors.lastname: Pappas
authors.forename: John E
authors.initials: JE
authors.lastname: Scarborough
mesh_terms: D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D014193:Trauma Centers / Q000706:statistics & numerical data*; D015599:Trauma Severity Indices; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D014947:Wounds and Injuries / Q000453:epidemiology* / Q000401:mortality*