title: Positive trend in survival to hospital discharge after out-of-hospital cardiac arrest: a quantitative review of the literature.
abstract: BACKGROUND
  Seven editions of cardiopulmonary resuscitation (CPR) and emergency cardiovascular care guidelines have been published with many changes, in particular, about CPR.
  
  
  OBJECTIVE
  The aim of our study was to evaluate the temporal trend of survival to hospital discharge after out-of-hospital cardiac arrest (OHCA) as a possible effect of guidelines changes.
  
  
  METHODS
  We searched PubMed for observational studies on 'survival to hospital discharge after OHCA'. Survival to discharge was the primary outcome; prehospital return of spontaneous circulation and survival to hospital admission were our secondary endpoints. All data were analyzed according to the year of inclusion: group 1 before 2000; group 2 between 2000 and 2005; and group 3 after 2005. Mortality rates were compared between groups by means of a group frequency-weighted log-linear model.
  
  
  RESULTS
  We considered 38 of 201 studies for a total of 156 301 patients. Survival to hospital discharge rate was 5.0% [95% confidence interval (CI) 4.9-5.2) in group 1; 6.1% (95% CI 5.9-6.4) in group 2; and 9.1% (95% CI 8.9-9.4) in group 3 (P < 0.001). A statistically significant decrease in risk of mortality in group 2 vs. group 1 (risk ratio 0.988, 95% CI 0. 985-0.0.992, P < 0.001) and in group 3 vs. group 2 (risk ratio 0.967, 95% CI 0.964-0.971, P < 0.001) was observed. Similar trends were observed for return of spontaneous circulation and survival to hospital admission.
  
  
  CONCLUSIONS
  Survival to hospital discharge after OHCA has significantly improved. Many aspects may influence survival, but surely, the reduction of time and an early and good quality CPR have positively influenced the outcome.
authors: aDepartment of Cardiology bDepartment of Biometry & Statistics cAAT 118 AREU Emergency System, Fondazione IRCCS Policlinico San Matteo dAPT American Heart Association Training Centre, Bornasco, Pavia, Italy.
authors: Simone
authors: S
authors: Savastano
authors: Catherine
authors: C
authors: Klersy
authors: Maurizio
authors: M
authors: Raimondi
authors: Karen
authors: K
authors: Langord
authors: Vincenzo
authors: V
authors: Vanni
authors: Roberto
authors: R
authors: Rordorf
authors: Alessandro
authors: A
authors: Vicentini
authors: Barbara
authors: B
authors: Petracci
authors: Maurizio
authors: M
authors: Landolina
authors: Luigi Oltrona
authors: LO
authors: Visconti
mesh_terms: D022561:Advanced Cardiac Life Support / Q000592:standards; D016887:Cardiopulmonary Resuscitation / Q000592:standards; D006801:Humans; D009026:Mortality / Q000639:trends; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality* / Q000628:therapy; D010351:Patient Discharge / Q000639:trends; D017410:Practice Guidelines as Topic