title: Survival after out-of-hospital cardiac arrest in relation to sex: a nationwide registry-based study.
abstract: OBJECTIVE
  Crude survival has increased following an out-of-hospital cardiac arrest (OHCA). We aimed to study sex-related differences in patient characteristics and survival during a 10-year study period.
  
  
  METHODS
  Patients≥12 years old with OHCA of a presumed cardiac cause, and in whom resuscitation was attempted, were identified through the Danish Cardiac Arrest Registry 2001-2010. A total of 19,372 patients were included.
  
  
  RESULTS
  One-third were female, with a median age of 75 years (IQR 65-83). Compared to females, males were five years younger; and less likely to have severe comorbidities, e.g., chronic obstructive pulmonary disease (12.8% vs. 16.5%); but more likely to have arrest outside of the home (29.4% vs. 18.7%), receive bystander CPR (32.9% vs. 25.9%), and have a shockable rhythm (32.6% vs. 17.2%), all p<0.001. Thirty-day crude survival increased in males (3.0% in 2001 to 12.9% in 2010); and in females (4.8% in 2001 to 6.7% in 2010), p<0.001. Multivariable logistic regression analyses adjusted for patient characteristics including comorbidities, showed no survival difference between sexes in patients with a non-shockable rhythm (OR 1.00; CI 0.72-1.40), while female sex was positively associated with survival in patients with a shockable rhythm (OR 1.31; CI 1.07-1.59). Analyses were rhythm-stratified due to interaction between sex and heart rhythm; there was no interaction between sex and calendar-year.
  
  
  CONCLUSIONS
  Temporal increase in crude survival was more marked in males due to poorer prognostic characteristics in females with a lower proportion of shockable rhythm. In an adjusted model, female sex was positively associated with survival in patients with a shockable rhythm.
authors: Department of Cardiology, Copenhagen University Hospital Gentofte, Niels Andersens Vej 65, 2900 Hellerup, Denmark. Electronic address: Mads.Wissenberg.Joergensen@regionh.dk.
authors: Mads
authors: M
authors: Wissenberg
authors: Department of Cardiology, Copenhagen University Hospital Gentofte, Niels Andersens Vej 65, 2900 Hellerup, Denmark.
authors: Carolina Malta
authors: CM
authors: Hansen
authors: Department of Cardiology, Copenhagen University Hospital Gentofte, Niels Andersens Vej 65, 2900 Hellerup, Denmark.
authors: Fredrik
authors: F
authors: Folke
authors: The Emergency Medical Services, Capital Region of Denmark, Telegrafvej 5, 2750 Ballerup, Denmark.
authors: Freddy K
authors: FK
authors: Lippert
authors: Department of Cardiology, Copenhagen University Hospital Gentofte, Niels Andersens Vej 65, 2900 Hellerup, Denmark.
authors: Peter
authors: P
authors: Weeke
authors: Department of Cardiology, Copenhagen University Hospital Gentofte, Niels Andersens Vej 65, 2900 Hellerup, Denmark.
authors: Lena
authors: L
authors: Karlsson
authors: Department of Cardiology, Copenhagen University Hospital Gentofte, Niels Andersens Vej 65, 2900 Hellerup, Denmark.
authors: Shahzleen
authors: S
authors: Rajan
authors: Department of Cardiology, Copenhagen University Hospital Gentofte, Niels Andersens Vej 65, 2900 Hellerup, Denmark.
authors: Kathrine Bach
authors: KB
authors: Søndergaard
authors: The Department of Anesthesiology, Cardiovascular Research Center, Aalborg University Hospital, Sdr. Skovvej 15, 9000 Aalborg, Denmark.
authors: Kristian
authors: K
authors: Kragholm
authors: The Prehospital Emergency Medical Services, Central Denmark Region, Olof Palmes Allé 34, 8200 Aarhus N, Denmark.
authors: Erika Frischknecht
authors: EF
authors: Christensen
authors: The Emergency Medical Services, Capital Region of Denmark, Telegrafvej 5, 2750 Ballerup, Denmark.
authors: Søren L
authors: SL
authors: Nielsen
authors: The Heart Centre, Copenhagen University Hospital Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark.
authors: Lars
authors: L
authors: Køber
authors: Department of Cardiology, Copenhagen University Hospital Gentofte, Niels Andersens Vej 65, 2900 Hellerup, Denmark; The National Institute of Public Health, University of Southern Denmark, Øster Farimagsgade 5, 1353 Copenhagen, Denmark.
authors: Gunnar H
authors: GH
authors: Gislason
authors: The Institute of Health, Science and Technology, Aalborg University, Niels Jernes Vej 12, 9220 Aalborg East, Denmark.
authors: Christian
authors: C
authors: Torp-Pedersen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003718:Denmark; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality*; D012042:Registries; D017678:Sex Distribution; D015996:Survival Rate
keywords: Cardiac arrest; Resuscitation; Sex; Survival