title: Patient Outcomes at Urban and Suburban Level I Versus Level II Trauma Centers.
abstract: OBJECTIVE
  Regionalized systems of trauma care and level verification are promulgated by the American College of Surgeons. Whether patient outcomes differ between the 2 highest verifications, Levels I and II, is unknown. In contrast to Level II centers, Level I centers are required to care for a minimum number of severely injured patients, have immediate availability of subspecialty services and equipment, and demonstrate research, substance abuse screening, and injury prevention. We compare risk-adjusted mortality outcomes at Levels I and II centers.
  
  
  METHODS
  This was an analysis of data from the 2012 to 2014 Los Angeles County Trauma and Emergency Medical Information System. The system includes 14 trauma centers: 5 Level I and 9 Level II centers. Patients meeting criteria for transport to a trauma center are routed to the closest center, regardless of verification level. All adult patients (≥15 years) treated at any of the trauma centers were included. Outcomes of patients treated at Level I versus Level II centers were compared with 2 validated risk-adjusted models: Trauma Score-Injury Severity Score (TRISS) and the Haider model.
  
  
  RESULTS
  Adult subjects (33,890) were treated at a Level I center; 29,724, at a Level II center. We found lower overall mortality at Level II centers compared with Level I, using TRISS (odds ratio 0.68; 95% confidence interval 0.59 to 0.78) and Haider (odds ratio 0.84; 95% confidence interval 0.73 to 0.97).
  
  
  CONCLUSIONS
  In this cohort of patients treated at urban and suburban trauma centers, treatment at a Level II trauma center was associated with overall risk-adjusted reduced mortality relative to that at a Level I center. In the subset of penetrating trauma, no differences in mortality were found. Further study is warranted to determine optimal trauma system configuration and allocation of resources.
authors.affiliation: Harbor-UCLA Medical Center and the Los Angeles Biomedical Research Institute at Harbor-UCLA, Torrance, CA; David Geffen School of Medicine at UCLA, Los Angeles, CA. Electronic address: akaji@emedharbor.edu.
authors.forename: Amy H
authors.initials: AH
authors.lastname: Kaji
authors.affiliation: Harbor-UCLA Medical Center and the Los Angeles Biomedical Research Institute at Harbor-UCLA, Torrance, CA; David Geffen School of Medicine at UCLA, Los Angeles, CA; Los Angeles County Emergency Medical Services Agency, Santa Fe Springs, CA.
authors.forename: Nichole
authors.initials: N
authors.lastname: Bosson
authors.affiliation: Harbor-UCLA Medical Center and the Los Angeles Biomedical Research Institute at Harbor-UCLA, Torrance, CA; David Geffen School of Medicine at UCLA, Los Angeles, CA; Los Angeles County Emergency Medical Services Agency, Santa Fe Springs, CA.
authors.forename: Marianne
authors.initials: M
authors.lastname: Gausche-Hill
authors.affiliation: David Geffen School of Medicine at UCLA, Los Angeles, CA; Ronald Reagan UCLA Medical Center, Los Angeles, CA.
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Dawes
authors.affiliation: Harbor-UCLA Medical Center and the Los Angeles Biomedical Research Institute at Harbor-UCLA, Torrance, CA; David Geffen School of Medicine at UCLA, Los Angeles, CA.
authors.forename: Brant
authors.initials: B
authors.lastname: Putnam
authors.affiliation: Saint Francis Medical Center, Los Angeles, CA.
authors.forename: Tchaka
authors.initials: T
authors.lastname: Shepherd
authors.affiliation: Harbor-UCLA Medical Center and the Los Angeles Biomedical Research Institute at Harbor-UCLA, Torrance, CA; David Geffen School of Medicine at UCLA, Los Angeles, CA.
authors.forename: Roger J
authors.initials: RJ
authors.lastname: Lewis
mesh_terms: D000328:Adult; D002423:Cause of Death; D003131:Combined Modality Therapy; D005260:Female; D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D015601:Injury Severity Score; D015141:Los Angeles / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D017063:Outcome Assessment, Health Care; D012189:Retrospective Studies; D018570:Risk Assessment; D014193:Trauma Centers / Q000145:classification*; D014505:Urban Population; D014947:Wounds and Injuries / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy; D055815:Young Adult