title: Impact of a physician-staffed helicopter on a regional trauma system: a prospective, controlled, observational study.
abstract: BACKGROUND
  This study aims to compare the trauma system before and after implementing a physician-staffed helicopter emergency medical service (PS-HEMS). Our hypothesis was that PS-HEMS would reduce time from injury to definitive care for severely injured patients.
  
  
  METHODS
  This was a prospective, controlled, observational study, involving seven local hospitals and one level I trauma centre using a before and after design. All patients treated by a trauma team within a 5-month period (1 December 2009-30 April 2010) prior to and a 12-month period (1 May 2010-30 April 2011) after implementing a PS-HEMS were included. We compared time from dispatch of the first ground ambulance to arrival in the trauma centre for patients with Injury Severity Score (ISS) > 15. Secondary end points were the proportion of secondary transfers and 30-day mortality.
  
  
  RESULTS
  We included 1788 patients, of which 204 had an ISS > 15. The PS-HEMS transported 44 severely injured directly to the trauma centre resulting in a reduction of secondary transfers from 50% before to 34% after implementation (P = 0.04). Median delay for definitive care for severely injured patients was 218 min before and 90 min after implementation (P < 0.01). The 30-day mortality was reduced from 29% (16/56) before to 14% (21/147) after PS-HEMS (P = 0.02). Logistic regression showed PS-HEMS had an odds ratio (OR) for survival of 6.9 compared with ground transport.
  
  
  CONCLUSIONS
  Implementation of a PS-HEMS was associated with significant reduction in time to the trauma centre for severely injured patients. We also observed significantly reduced proportions of secondary transfers and 30-day mortality.
authors.affiliation: Department of Anaesthesia Section 4231, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark. Hesselfeldt@hotmail.com
authors.forename: R
authors.initials: R
authors.lastname: Hesselfeldt
authors.forename: J
authors.initials: J
authors.lastname: Steinmetz
authors.forename: H
authors.initials: H
authors.lastname: Jans
authors.forename: M-L B
authors.initials: ML
authors.lastname: Jacobsson
authors.forename: D L
authors.initials: DL
authors.lastname: Andersen
authors.forename: K
authors.initials: K
authors.lastname: Buggeskov
authors.forename: M
authors.initials: M
authors.lastname: Kowalski
authors.forename: M
authors.initials: M
authors.lastname: Praest
authors.forename: L
authors.initials: L
authors.lastname: Øllgaard
authors.forename: P
authors.initials: P
authors.lastname: Höiby
authors.forename: L S
authors.initials: LS
authors.lastname: Rasmussen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017732:Air Ambulances / Q000706:statistics & numerical data*; D003718:Denmark; D004632:Emergency Medical Services / Q000379:methods*; D005260:Female; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D008875:Middle Aged; D010820:Physicians; D011446:Prospective Studies; D013997:Time Factors; D014947:Wounds and Injuries / Q000628:therapy*; D055815:Young Adult