title: Medically appropriate use of helicopter EMS: the mission acceptance/triage process.
abstract: BACKGROUND
  Appropriate use of helicopter emergency medical services (HEMS) ensures the maximum impact of a limited resource on improved health outcomes. Overtriage increases real and opportunity costs and may unjustifiably expose the program to small but inherent safety risks. The purpose of this study is to describe the mission acceptance process for an integrated, provincially based HEMS program and determine its utilization patterns.
  
  
  METHODS
  This is a retrospective review of patient care and administrative databases. All missions were reviewed to determine whether they were medically appropriate. "Appropriateness" was defined a priori as requiring admission to a critical care unit, death during transportation or in first 24 hours, or in the case of trauma, an injury severity scale (ISS) score > or = 12. Overtriage was defined as not meeting these a priori definitions.
  
  
  RESULTS
  Five hundred eighty-four missions were reviewed from March 31, 2003 through December 31, 2004. Our mission acceptance process consists of three distinct but complementary phases: ongoing outreach education, scanning by dispatchers in an integrated dispatch center, and a clinician to online physician discussion about each case. The overall overtriage rate was 13.1%.
  
  
  CONCLUSIONS
  The rate of medically appropriate missions in this system is relatively high. Prospective research is required to improve HEMS triage systems.
authors.affiliation: Department of Emergency Medicine, Dalhouse University, Halifax, NS, Canada. david.petrie@dal.ca
authors.forename: David A
authors.initials: DA
authors.lastname: Petrie
authors.forename: John M
authors.initials: JM
authors.lastname: Tallon
authors.forename: Wilma
authors.initials: W
authors.lastname: Crowell
authors.forename: Ed
authors.initials: E
authors.lastname: Cain
authors.forename: Paula
authors.initials: P
authors.lastname: Martell
authors.forename: Dagmar
authors.initials: D
authors.lastname: McManus
mesh_terms: D017732:Air Ambulances / Q000458:organization & administration* / Q000706:statistics & numerical data; D003657:Decision Making; D006801:Humans; D009674:Nova Scotia; D012189:Retrospective Studies; D014218:Triage