title: In a mature trauma system, there is no difference in outcome (survival) between Level I and Level II trauma centers.
abstract: BACKGROUND
  The state of Pennsylvania (PA) has one of the oldest, most well-established trauma systems in the country. The requirements for verification for Level I versus Level II trauma centers within PA differ minimally (only in the requirement for patient volume, residency, and research). We hypothesized that there would be no difference in outcome at Level I versus Level II trauma centers.
  
  
  METHODS
  Odds of mortality for 16 Level I and 11 Level II hospitals in PA over a 5-year period (2004-2008) was computed using a random effects logistic regression model. Overall adjusted mortality rates at Level I versus Level II hospitals were compared using the nonparametric Wilcoxon's rank sum test. The crude mortality rates for 140,691 patients over the 5-year period were similar (5.07% Level II vs. 5.48% Level I), but statistically significant (odds ratio mortality at Level I = 1.084, p = 0.002 Fisher's exact test).
  
  
  RESULTS
  Although Level I centers had on average crude mortality rates that were higher than those of Level II centers, median adjusted mortality rates were not different for the two types of centers (Wilcoxon's rank sum test). Performance of Level I versus Level II shows considerable variability among centers (basic random effects model, age, blunt/penetrating, and Injury Severity Score [ISS]). However, Level II centers seem no different from Level I.
  
  
  CONCLUSIONS
  As trauma systems mature, the distinction between Level I and Level II trauma centers blurs. The hierarchal descriptors "Level I" or "Level II" in a mature trauma system is pejorative and implies in those hospitals labeled "Level II" as inferior, and as such should be replaced with nonhierarchal descriptors.
authors.affiliation: Division of Trauma/Critical Care, Lancaster General Health, Lancaster, Pennsylvania 17602, USA. frogers2@lghealth.org
authors.forename: Frederick B
authors.initials: FB
authors.lastname: Rogers
authors.forename: Turner
authors.initials: T
authors.lastname: Osler
authors.forename: John C
authors.initials: JC
authors.lastname: Lee
authors.forename: Lois
authors.initials: L
authors.lastname: Sakorafas
authors.forename: Daniel
authors.initials: D
authors.lastname: Wu
authors.forename: Tracy
authors.initials: T
authors.lastname: Evans
authors.forename: Mathew
authors.initials: M
authors.lastname: Edavettal
authors.forename: Michael
authors.initials: M
authors.lastname: Horst
mesh_terms: D000328:Adult; D005260:Female; D006302:Health Services Research; D017052:Hospital Mortality; D006801:Humans; D015601:Injury Severity Score; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010414:Pennsylvania / Q000453:epidemiology; D012372:ROC Curve; D012042:Registries; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D014193:Trauma Centers / Q000145:classification* / Q000592:standards; D015599:Trauma Severity Indices; D014947:Wounds and Injuries / Q000401:mortality*