title: Maryland's Helicopter Emergency Medical Services Experience From 2001 to 2011: System Improvements and Patients' Outcomes.
abstract: OBJECTIVE
  Helicopter emergency medical services (EMS) has become a well-established component of modern trauma systems. It is an expensive, limited resource with potential safety concerns. Helicopter EMS activation criteria intended to increase efficiency and reduce inappropriate use remain elusive and difficult to measure. This study evaluates the effect of statewide field trauma triage changes on helicopter EMS use and patient outcomes.
  
  
  METHODS
  Data were extracted from the helicopter EMS computer-aided dispatch database for in-state scene flights and from the state Trauma Registry for all trauma patients directly admitted from the scene or transferred to trauma centers from July 1, 2000, to June 30, 2011. Computer-aided dispatch flights were analyzed for periods corresponding to field triage protocol modifications intended to improve system efficiency. Outcomes were separately analyzed for trauma registry patients by mode of transport.
  
  
  RESULTS
  The helicopter EMS computer-aided dispatch data set included 44,073 transports. There was a statewide decrease in helicopter EMS usage for trauma patients of 55.9%, differentially affecting counties closer to trauma centers. The Trauma Registry data set included 182,809 patients (37,407 helicopter transports, 128,129 ambulance transports, and 17,273 transfers). There was an increase of 21% in overall annual EMS scene trauma patients transported; ground transports increased by 33%, whereas helicopter EMS transports decreased by 49%. Helicopter EMS patient acuity increased, with an attendant increase in patient mortality. However, when standardized with W statistics, both helicopter EMS- and ground-transported trauma patients showed sustained improvement in mortality.
  
  
  CONCLUSIONS
  Modifications to state protocols were associated with decreased helicopter EMS use and overall improved trauma patient outcomes.
authors.affiliation: Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore City, MD; Charles McC Mathias, Jr. National Study Center for Trauma & EMS, University of Maryland School of Medicine, Baltimore City, MD. Electronic address: jhirshon@umaryland.edu.
authors.forename: Jon Mark
authors.initials: JM
authors.lastname: Hirshon
authors.affiliation: Department of Anesthesiology, University of Maryland School of Medicine, Baltimore City, MD.
authors.forename: Samuel M
authors.initials: SM
authors.lastname: Galvagno
authors.affiliation: Charles McC Mathias, Jr. National Study Center for Trauma & EMS, University of Maryland School of Medicine, Baltimore City, MD.
authors.forename: Angela
authors.initials: A
authors.lastname: Comer
authors.affiliation: Department of Emergency Medicine, The Johns Hopkins University School of Medicine, Baltimore City, MD.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Millin
authors.affiliation: Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore City, MD; Maryland Institute for Emergency Medical Service Systems, Baltimore City, MD.
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: Floccare
authors.affiliation: Maryland Institute for Emergency Medical Service Systems, Baltimore City, MD.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Alcorta
authors.affiliation: Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore City, MD.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Lawner
authors.affiliation: Department of Emergency Medicine, The Johns Hopkins University School of Medicine, Baltimore City, MD.
authors.forename: Asa M
authors.initials: AM
authors.lastname: Margolis
authors.affiliation: Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore City, MD.
authors.forename: Jose V
authors.initials: JV
authors.lastname: Nable
authors.affiliation: Maryland Institute for Emergency Medical Service Systems, Baltimore City, MD.
authors.forename: Robert R
authors.initials: RR
authors.lastname: Bass
mesh_terms: D017732:Air Ambulances / Q000592:standards*; D000401:Aircraft; D017598:Efficiency, Organizational; D004632:Emergency Medical Services / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D008396:Maryland; D010043:Outcome and Process Assessment, Health Care; D058996:Quality Improvement; D012042:Registries; D014218:Triage