title: Definitive care in level 3 trauma centres after severe injury: A comparison of clinical characteristics and outcomes.
abstract: BACKGROUND
  The role of level 3 trauma centres (TC) in inclusive trauma systems has not been well defined. The absence of nationally recognised inter-facility transfer criteria for inclusive systems has often left individual level 3 TCs to decide upon their own what their spectrum of care is and particularly which severely injured patients to admit for definitive care.
  
  
  METHODS
  Retrospective cohort study in which the principal objective was to compare the characteristics and outcomes of severely injured (injury severity score>15) adult patients (≥18 years) who received definitive care at level 3 centres with severely injured adult patients who were transferred to level 1-2 TCs during the same time period. Data were derived from the National Trauma Data Bank (2010-2011). First, we utilised hierarchical logistic regression models to evaluate the risk-adjusted mortality of patients admitted at level 3 TCs compared to those who were transferred to level 1-2 TCs. Subgroup analysis was carried out for patients with isolated traumatic brain injury (iTBI). Finally, we explored the extent of variation in risk-adjusted mortality across level 3 TCs.
  
  
  RESULTS
  We identified 6433 severely injured patients who received definitive care across 150 level 3 TCs and 41,165 severely injured patients transferred to level 1-2 centres. Patients who received definitive care at level 3 TCs had a lower comorbidity burden and different injury profiles compared to those transferred to level 1-2 centres. There was no difference in crude mortality (10% vs. 11%, standardised difference 0.04); however, after risk-adjustment, the odds of death for patients who received definitive care at level 3 TCs were 1.24-fold higher (95%CI 1.08-1.43) when compared to those transferred to level 1-2 centres. A trend towards a higher likelihood of death at level 3 centres was observed when analysis was limited to patients with iTBI. Risk-adjusted mortality across level 3 TCs was with few exceptions, homogeneous (<10% of level 3 TCs were outliers with higher/lower mortality).
  
  
  CONCLUSIONS
  Level 3 trauma centres are providing definitive care for a subset of severely injured patients. Our findings suggest that the outcomes of severely injured patients admitted at level 3 centres might be worse compared to those transferred to level 1-2 centres; a finding independent of performance outliers. Further work is required to elucidate the determinants of admission after severe injury at level 3 trauma centres.
authors.affiliation: Department of Surgery and Division of General Surgery, University of Toronto, ON, Canada; Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada. Electronic address: david.gomezjaramillo@mail.utoronto.ca.
authors.forename: David
authors.initials: D
authors.lastname: Gomez
authors.affiliation: Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada.
authors.forename: Aziz S
authors.initials: AS
authors.lastname: Alali
authors.affiliation: Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada.
authors.forename: Wei
authors.initials: W
authors.lastname: Xiong
authors.affiliation: Department of Surgery, University of Tennessee Health Science Center, Memphis, TN, United States.
authors.forename: Ben L
authors.initials: BL
authors.lastname: Zarzaur
authors.affiliation: Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, United States.
authors.forename: N Clay
authors.initials: NC
authors.lastname: Mann
authors.affiliation: Department of Surgery and Division of General Surgery, University of Toronto, ON, Canada; Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada.
authors.forename: Avery B
authors.initials: AB
authors.lastname: Nathens
mesh_terms: D002170:Canada / Q000453:epidemiology; D002985:Clinical Protocols; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D015601:Injury Severity Score; D016015:Logistic Models; D008297:Male; D010360:Patient Transfer / Q000458:organization & administration* / Q000592:standards; D012189:Retrospective Studies; D012307:Risk Factors; D014193:Trauma Centers / Q000458:organization & administration* / Q000592:standards; D014481:United States / Q000453:epidemiology; D014947:Wounds and Injuries / Q000401:mortality / Q000628:therapy*
keywords: Inter-facility transfer; Level 3 trauma centers; Trauma systems