title: Physiologic field triage criteria for identifying seriously injured older adults.
abstract: OBJECTIVE
  To evaluate the ability of out-of-hospital physiologic measures to predict serious injury for field triage purposes among older adults and potentially reduce the undertriage of seriously injured elders to non-trauma hospitals.
  
  
  METHODS
  This was a retrospective cohort study involving injured adults 55 years and older transported by 94 emergency medical services (EMS) agencies to 122 hospitals (trauma and non-trauma) in 7 regions of the western United States from January 1, 2006 to December 31, 2008. We evaluated initial out-of-hospital Glasgow Coma Scale (GCS) score, systolic blood pressure (SBP), respiratory rate, heart rate, shock index (SBP ÷ heart rate), out-of-hospital procedures, mechanism of injury, and patient demographics. The primary outcome was "serious injury," defined as Injury Severity Score (ISS) ≥ 16, as a measure of trauma center need. We used multivariable regression models, fractional polynomials and binary recursive partitioning to evaluate appropriate physiologic cut-points and the value of different physiologic triage criteria.
  
  
  RESULTS
  A total of 44,890 injured older adults were evaluated and transported by EMS, of whom 2,328 (5.2%) had ISS ≥ 16. Nonlinear associations existed between all physiologic measures and ISS ≥ 16 (unadjusted and adjusted p ≤ 0.001 for all,), except for heart rate (adjusted p = 0.48). Revised physiologic triage criteria included GCS score ≤ 14; respiratory rate < 10 or > 24 breaths per minute or assisted ventilation; and SBP < 110 or > 200 mmHg. Compared to current triage practices, the revised criteria would increase triage sensitivity from 78.6 to 86.3% (difference 7.7%, 95% CI 6.1-9.6%), reduce specificity from 75.5 to 60.7% (difference 14.8%, 95% CI 14.3-15.3%), and increase the proportion of patients without serious injuries transported to major trauma centers by 60%.
  
  
  CONCLUSIONS
  Existing out-of-hospital physiologic triage criteria could be revised to better identify seriously injured older adults at the expense of increasing overtriage to major trauma centers.
authors.forename: Craig D
authors.initials: CD
authors.lastname: Newgard
authors.forename: Derek
authors.initials: D
authors.lastname: Richardson
authors.forename: James F
authors.initials: JF
authors.lastname: Holmes
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Rea
authors.forename: Renee Y
authors.initials: RY
authors.lastname: Hsia
authors.forename: N Clay
authors.initials: NC
authors.lastname: Mann
authors.forename: Kristan
authors.initials: K
authors.lastname: Staudenmayer
authors.forename: Erik D
authors.initials: ED
authors.lastname: Barton
authors.forename: Eileen M
authors.initials: EM
authors.lastname: Bulger
authors.forename: Jason S
authors.initials: JS
authors.lastname: Haukoos
mesh_terms: D000328:Adult; D015331:Cohort Studies; D004632:Emergency Medical Services / Q000379:methods*; D005260:Female; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014218:Triage / Q000379:methods*; D014481:United States; D014947:Wounds and Injuries / Q000145:classification / Q000175:diagnosis*
keywords: EMS; trauma; triage