title: A 26-year comparative review of United Kingdom helicopter emergency medical services crashes and serious incidents.
abstract: BACKGROUND
  The use of helicopter emergency medical services (HEMS) has increased substantially in the United Kingdom since 1987. There are currently no data on the rate of crashes and serious incidents related to HEMS in the United Kingdom. The aims of this article were to present data from a 26-year period since the start of HEMS operations in the United Kingdom and to compare them with published data from Germany, Australia, and the United States. Factors identified as affecting the safety of HEMS operations will also be discussed.
  
  
  METHODS
  A PubMed search was performed to retrieve published data on accident rates and safety discussions for international HEMS using the key words HEMS, helicopter, emergency medical services, accident, incident, and crash. The details of every helicopter crash in the United States since the beginning of HEMS operations was obtained and reviewed to identify those that involved HEMS aircraft. This novel UK information was compared with published data from three international systems.
  
  
  RESULTS
  A total of 13 accidents or serious incidents involving HEMS aircraft were identified from Civil Aviation Authority records, only 1 of which was a fatal accident. It was estimated that approximately 230,000 HEMS missions occurred in the United Kingdom between 1987 and 2013, giving an absolute accident incidence of approximately 0.0057% and a fatal accident incidence of approximately 0.00043%. The accident and fatal accident rate per 10,000 missions in the United Kingdom was 0.57 and 0.04, respectively. This compares with published rates from Germany, Australia, and the United States with accident rate per 10,000 missions ranging between 0.57 and 0.75 and fatal accident rates per 10,000 missions ranging between 0.04 and 0.23.
  
  
  CONCLUSIONS
  Accidents and serious incidents relating to HEMS operations in the United Kingdom have been comprehensively identified for the first time, allowing an estimation of overall accident and fatal accident rates and comparison with other countries' HEMS operations. Data collection and analysis were hampered by obscurity of data sources and poor availability of data. In a time of increasing HEMS use in the United Kingdom, it is essential to be mindful of safety, and standardization of data collection will improve focus in this important area.
authors.affiliation: From the Essex and Herts Air Ambulance Trust (A.C.), The Business Centre, Earls Colne Business Park, Earls Colne, Colchester, Essex; and East Anglian Air Ambulance (T.J.H.), Norwich, United Kingdom; and Reach Air Medical Services (P.H.G.), Santa Rosa, California.
authors.forename: Adam
authors.initials: A
authors.lastname: Chesters
authors.forename: Phillip H
authors.initials: PH
authors.lastname: Grieve
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Hodgetts
mesh_terms: D000060:Accidents, Aviation / Q000401:mortality*; D017732:Air Ambulances / Q000706:statistics & numerical data*; D000401:Aircraft; D004632:Emergency Medical Services / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D006113:United Kingdom / Q000453:epidemiology; D014947:Wounds and Injuries / Q000453:epidemiology*