title: Factors Associated With Successful Resuscitation After Out-of-Hospital Cardiac Arrest and Temporal Trends in Survival and Comorbidity.
abstract: OBJECTIVE
  Out-of-hospital cardiac arrest has an overall poor prognosis. We sought to identify what temporal trends and influencing factors existed for this condition in one region.
  
  
  METHODS
  We studied consecutive out-of-hospital cardiac arrest patients from 2007 to 2011 with attempted resuscitation in Copenhagen. From an Utstein database, we assessed survival to admission and comorbidity with the Charlson comorbidity index from the National Patient Registry and employment status from the Danish Rational Economic Agents Model database. We used logistic regression analyses to identify factors associated with outcome.
  
  
  RESULTS
  Of a total of 2,527 attempted resuscitations in out-of-hospital cardiac arrest patients, 40% (n=1,015) were successfully resuscitated and admitted to the hospital. The strongest independent factors associated with successful resuscitation were shockable primary rhythm (multivariate odds ratio [OR]=3.9; 95% confidence interval [CI] 3.1 to 5.0), witnessed arrest (multivariate OR=3.5; 95% CI 2.7 to 4.6), and out-of-hospital cardiac arrest in a public area (multivariate OR=2.1; 95% CI 1.6 to 2.8), whereas no comorbidity (multivariate OR=1.1; 95% CI 0.8 to 1.45), sex (multivariate OR=1.14; 95% CI 0.91 to 1.44), and employment status (multivariate OR=1.17; 95% CI 0.89 to 1.56) were not independently associated with outcome. The number of patients with a high comorbidity burden (Charlson comorbidity index ≥3) increased during the study period (P trend <.001), from 18% to 31% (P trend <.001), whereas the percentage of out-of-hospital cardiac arrest patients with successful resuscitation to hospital admission increased by 3% per year during the study period, from 37% in 2007 to 43% in 2011 (P trend <.001).
  
  
  CONCLUSIONS
  Our observations confirm the importance of key features that influence out-of-hospital cardiac arrest survival to hospital admission but are not highly influenced by public health actions. Despite increased illness burden, this short term outcome from cardiac arrest improved as care system efforts matured.
authors.affiliation: Department of Cardiology, the Heart Centre, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark. Electronic address: helle.soholm@gmail.com.
authors.forename: Helle
authors.initials: H
authors.lastname: Søholm
authors.affiliation: Department of Cardiology, the Heart Centre, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Hassager
authors.affiliation: Emergency Medical Services, the Capital Region of Denmark, Copenhagen, Denmark.
authors.forename: Freddy
authors.initials: F
authors.lastname: Lippert
authors.affiliation: Department of Cardiology, the Heart Centre, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
authors.forename: Matilde
authors.initials: M
authors.lastname: Winther-Jensen
authors.affiliation: Department of Cardiology, the Heart Centre, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
authors.forename: Jakob Hartvig
authors.initials: JH
authors.lastname: Thomsen
authors.affiliation: Department of Anaesthesiology and Intensive Care, Skåne University Hospital, Lund University, Lund, Sweden.
authors.forename: Hans
authors.initials: H
authors.lastname: Friberg
authors.affiliation: Department of Cardiology, the Heart Centre, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
authors.forename: John
authors.initials: J
authors.lastname: Bro-Jeppesen
authors.affiliation: Department of Cardiology, the Heart Centre, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Køber
authors.affiliation: Department of Cardiology, the Heart Centre, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
authors.forename: Jesper
authors.initials: J
authors.lastname: Kjaergaard
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016887:Cardiopulmonary Resuscitation / Q000401:mortality*; D015897:Comorbidity; D016208:Databases, Factual; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000453:epidemiology / Q000401:mortality / Q000628:therapy*; D010343:Patient Admission; D012042:Registries; D012189:Retrospective Studies; D055815:Young Adult