title: Comparative study of ED mortality risk of US trauma patients treated at level I and level II vs nontrauma centers.
abstract: BACKGROUND
  Prior studies of undertriage have not made comparisons across multiple trauma levels.
  
  
  METHODS
  Emergency department data was extracted from the Nationwide Emergency Department Sample for major trauma patients. We considered patients with moderate injuries (Injury Severity Score, ISS=16-24) and severe injuries (ISS=25-75) separately. Conditional logistic regression modeling was used to compare the odds of ED mortality for level I trauma centers (TC I) vs. nontrauma centers (NTC) and level II trauma centers (TC II) vs. NTC. An innovative 1:1:1 optimal matching (an extension of the traditional pair matching) was used to balance patient characteristics in three groups. To facilitate matching of all NTC patients, 3 subgroups were developed for ISS=16-24 and 2 subgroups for ISS=25-75. Sensitivity analyses were performed to assess the strength of the association between trauma center designation and ED mortality.
  
  
  RESULTS
  For ISS=16-24, 2 of 3 subgroups had marginally significant reduced odds of ED mortality when properly triaged (TC I vs. NTC [T1:OR=0.63; 95%CI: 0.45 - 0.89, T2:OR=0.71;95%CI:0.51-0.99]). For ISS=25-75, both subgroups had significantly reduced odds of emergency department mortality when properly triaged (H1: TC I vs. NTC [OR=0.61; 95%CI: 0.50-0.74]; TC II vs. NTC [OR=0.49; 95%CI: 0.38 - 0.63]; H2: TC I vs. NTC [OR=0.50; 95%CI: 0.41 - 0.60]; TC II vs. NTC [OR=0.42; 95%CI: 0.33 - 0.53]). Conclusions for ISS 25-75 were robust to a hypothesized unobserved confounding variable as shown in sensitivity analysis.
  
  
  CONCLUSIONS
  Trauma patients with ISS≥25 received most benefit from proper triage. Efforts to reduce undertriage should focus on this population.
authors.affiliation: Center for Pediatric Trauma Research, Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205; Center for Injury Research and Policy, Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205; The Ohio State University College of Medicine, 370 West 9th Ave, Columbus, OH, 43210.
authors.forename: Brian P
authors.initials: BP
authors.lastname: Vickers
authors.affiliation: Center for Pediatric Trauma Research, Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205; Center for Injury Research and Policy, Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205.
authors.forename: Junxin
authors.initials: J
authors.lastname: Shi
authors.affiliation: Division of Biostatistics, The Ohio State University College of Public Health, Cunz Hall, 1841 Neil Ave, Columbus, OH, 43210.
authors.forename: Bo
authors.initials: B
authors.lastname: Lu
authors.affiliation: Center for Pediatric Trauma Research, Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205; Center for Injury Research and Policy, Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205.
authors.forename: Krista K
authors.initials: KK
authors.lastname: Wheeler
authors.affiliation: Center for Pediatric Trauma Research, Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205; Center for Injury Research and Policy, Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205.
authors.forename: Jin
authors.initials: J
authors.lastname: Peng
authors.affiliation: Center for Pediatric Trauma Research, Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205; The Ohio State University College of Medicine, 370 West 9th Ave, Columbus, OH, 43210; Trauma Program, Department of Pediatric Surgery, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205.
authors.forename: Jonathan I
authors.initials: JI
authors.lastname: Groner
authors.affiliation: Center for Pediatric Trauma Research, Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205; Trauma Program, Department of Pediatric Surgery, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205.
authors.forename: Kathryn J
authors.initials: KJ
authors.lastname: Haley
authors.affiliation: Center for Pediatric Trauma Research, Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205; Center for Injury Research and Policy, Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205; The Ohio State University College of Medicine, 370 West 9th Ave, Columbus, OH, 43210. Electronic address: Huiyun.Xiang@NationwideChildrens.org.
authors.forename: Huiyun
authors.initials: H
authors.lastname: Xiang
mesh_terms: D000293:Adolescent; D000328:Adult; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D015601:Injury Severity Score; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014193:Trauma Centers; D014218:Triage; D014481:United States / Q000453:epidemiology; D014947:Wounds and Injuries / Q000401:mortality*; D055815:Young Adult