title: Cardiac arrest outside and inside hospital in a community: mechanisms behind the differences in outcome and outcome in relation to time of arrest.
abstract: BACKGROUND
  The aim was to compare characteristics and outcome after cardiac arrest where cardiopulmonary resuscitation was attempted outside and inside hospital over 12 years.
  
  
  METHODS
  All out-of-hospital cardiac arrests (OHCAs) in Göteborg between 1994 and 2006 and all in-hospital cardiac arrests (IHCAs) in 1 of the city's 2 hospitals for whom the rescue team was called between 1994 and 2006 were included in the survey.
  
  
  RESULTS
  The study included 2,984 cases of OHCA and 1,478 cases of IHCA. Patients with OHCA differed from those with an IHCA; they were younger, included fewer women, were less frequently found in ventricular fibrillation, and were treated later. If patients were found in a shockable rhythm, survival to 1 month/discharge was 18% after OHCA and 61% after IHCA (P < .0001). Corresponding values for a nonshockable rhythm were 3% and 21% (P < .0001). Survival was higher on daytime and weekdays as compared with nighttime and weekends after IHCA but not after OHCA. Among patients found in a shockable rhythm, a multivariate analysis considering age, gender, witnessed status, delay to defibrillation, time of day, day of week, and location showed that IHCA was associated with increased survival compared with OHCA (adjusted odds ratio 3.18, 95% CI 2.07-4.88).
  
  
  CONCLUSIONS
  Compared with OHCA, the survival of patients with IHCA increased 3-fold for shockable rhythm and 7-fold for nonshockable rhythm in our practice setting. If patients were found in a shockable rhythm, the higher survival after IHCA was only partly explained by a shorter treatment delay. The time and day of CA were associated with survival in IHCA but not OHCA.
authors.affiliation: Institution of Medicine, Department of Molecular and Clinical Medicine, Sahlgrenska University Hospital, Göteborg, Sweden.
authors.forename: Martin
authors.initials: M
authors.lastname: Fredriksson
authors.forename: Solveig
authors.initials: S
authors.lastname: Aune
authors.forename: Angela
authors.initials: A
authors.lastname: Bång
authors.forename: Ann-Britt
authors.initials: AB
authors.lastname: Thorén
authors.forename: Jonny
authors.initials: J
authors.lastname: Lindqvist
authors.forename: Thomas
authors.initials: T
authors.lastname: Karlsson
authors.forename: Johan
authors.initials: J
authors.lastname: Herlitz
mesh_terms: D000368:Aged; D016887:Cardiopulmonary Resuscitation; D004632:Emergency Medical Services; D005260:Female; D006323:Heart Arrest / Q000401:mortality* / Q000628:therapy; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D016019:Survival Analysis; D013548:Sweden; D016896:Treatment Outcome