title: Effects of helicopter service on survival after trauma. Design of study predisposed to type II error.
authors.forename: A D
authors.initials: AD
authors.lastname: Maclean
authors.forename: C J
authors.initials: CJ
authors.lastname: Kirk
authors.forename: T J
authors.initials: TJ
authors.lastname: Coats
authors.forename: F W
authors.initials: FW
authors.lastname: Cross
mesh_terms: D017732:Air Ambulances; D004632:Emergency Medical Services; D006801:Humans; D008131:London / Q000453:epidemiology; D012107:Research Design; D014947:Wounds and Injuries / Q000401:mortality*