title: Prehospital injury deaths--strengthening the case for prevention: nationwide cohort study.
abstract: BACKGROUND
  To determine the frequency and characteristics of prehospital deaths compared with hospital deaths in different subpopulations with severe injuries.
  
  
  METHODS
  Population-based cohort study using person-based linkage of the Swedish nationwide hospital discharge register with death certificate data. In all, 28,715 injury deaths were identified among 419,137 cases of severe injury during 1998 to 2004. Prehospital deaths were defined as autopsied out-of-hospital deaths with injury as the underlying cause. Their impact on mortality prediction was assessed using the International Classification of Disease Injury Severity Score with the C statistic as a measure of discrimination.
  
  
  RESULTS
  The majority of all injury deaths occurred either at the scene or before hospitalization. Among persons younger than 65 years, for each hospital death there were nine prehospital deaths. A high proportion of deaths from drowning, suffocation, and firearm injuries were prehospital (85, 82, and 67% of all cases, respectively). More than 90% of hospital deaths resulted from unintentional injuries, while only 43% of prehospital deaths were unintentional. The largest increase in a cause-specific case fatality risk estimate was seen for poisoning, where inclusion of prehospital deaths increased the risk estimate from 1.6% to 22.8%. Injury mortality prediction based on International Classification of Disease Injury Severity Score improved when prehospital deaths were added to hospital data (C statistic increased from 0.86 to 0.93).
  
  
  CONCLUSIONS
  Prehospital deaths constitute the majority of trauma deaths and differ in major characteristics from hospital deaths. The high proportion of prehospital deaths among young and middle aged people highlights the potential impact of preventive efforts.
  
  
  METHODS
  III.
authors.affiliation: Department of Surgical Sciences-Anesthesiology and Intensive Care, Uppsala Clinical Research Center, Uppsala University, Uppsala, Sweden. rolf.gedeborg@surgsci.uu.se
authors.forename: Rolf
authors.initials: R
authors.lastname: Gedeborg
authors.forename: Li-Hui
authors.initials: LH
authors.lastname: Chen
authors.forename: Ingemar
authors.initials: I
authors.lastname: Thiblin
authors.forename: Liisa
authors.initials: L
authors.lastname: Byberg
authors.forename: Håkan
authors.initials: H
authors.lastname: Melhus
authors.forename: Karl
authors.initials: K
authors.lastname: Michaelsson
authors.forename: Margaret
authors.initials: M
authors.lastname: Warner
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D002423:Cause of Death / Q000639:trends; D003644:Death Certificates; D004632:Emergency Medical Services / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D008875:Middle Aged; D012042:Registries / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D017678:Sex Distribution; D015996:Survival Rate / Q000639:trends; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors; D015599:Trauma Severity Indices; D014947:Wounds and Injuries / Q000175:diagnosis / Q000401:mortality*; D055815:Young Adult