title: Automated external defibrillators inaccessible to more than half of nearby cardiac arrests in public locations during evening, nighttime, and weekends.
abstract: BACKGROUND
  Despite wide dissemination, use of automated external defibrillators (AEDs) in community settings is limited. We assessed how AED accessibility affected coverage of cardiac arrests in public locations.
  
  
  RESULTS
  We identified cardiac arrests in public locations (1994-2011) in terms of location and time and viewed them in relation to the location and accessibility of all AEDs linked to the emergency dispatch center as of December 31, 2011, in Copenhagen, Denmark. AED coverage of cardiac arrests was defined as cardiac arrests within 100 m (109.4 yd) of an AED and further categorized according to AED accessibility at the time of cardiac arrest. Daytime, evening, and nighttime were defined as 8 am to 3:59 pm, 4 to 11:59 pm, and midnight to 7:59 am, respectively. Of 1864 cardiac arrests in public locations, 61.8% (n=1152) occurred during the evening, nighttime, or weekends. Of 552 registered AEDs, 9.1% (n=50) were accessible at all hours, and 96.4% (n=532) were accessible during the daytime on all weekdays. Regardless of AED accessibility, 28.8% (537 of 1864) of all cardiac arrests were covered by an AED. Limited AED accessibility decreased coverage of cardiac arrests by 4.1% (9 of 217) during the daytime on weekdays and by 53.4% (171 of 320) during the evening, nighttime, and weekends.
  
  
  CONCLUSIONS
  Limited AED accessibility at the time of cardiac arrest decreased AED coverage by 53.4% during the evening, nighttime, and weekends, which is when 61.8% of all cardiac arrests in public locations occurred. Thus, not only strategic placement but also uninterrupted AED accessibility warrant attention if public-access defibrillation is to improve survival after out-of-hospital cardiac arrest.
authors.affiliation: Department of Cardiology, Copenhagen University Hospital Gentofte, Hellerup (C.M.H., M.W., P.W., M.H.R., M.L., G.H.G., F.F.); Emergency Medical Services, Copenhagen, Capital Region of Denmark and Copenhagen University (F.K.L., S.L.N.); National Institute of Public Health, University of Southern Denmark, Copenhagen (G.H.G.); The Heart Centre, Copenhagen University Hospital Rigshospitalet, Copenhagen (L.K.); and Institute of Health, Science and Technology, Aalborg University, Aalborg (C.T.-P.), Denmark.
authors.forename: Carolina Malta
authors.initials: CM
authors.lastname: Hansen
authors.forename: Mads
authors.initials: M
authors.lastname: Wissenberg
authors.forename: Peter
authors.initials: P
authors.lastname: Weeke
authors.forename: Martin Huth
authors.initials: MH
authors.lastname: Ruwald
authors.forename: Morten
authors.initials: M
authors.lastname: Lamberts
authors.forename: Freddy Knudsen
authors.initials: FK
authors.lastname: Lippert
authors.forename: Gunnar Hilmar
authors.initials: GH
authors.lastname: Gislason
authors.forename: Søren Loumann
authors.initials: SL
authors.lastname: Nielsen
authors.forename: Lars
authors.initials: L
authors.lastname: Køber
authors.forename: Christian
authors.initials: C
authors.lastname: Torp-Pedersen
authors.forename: Fredrik
authors.initials: F
authors.lastname: Folke
mesh_terms: D000328:Adult; D039602:After-Hours Care / Q000706:statistics & numerical data*; D000368:Aged; D000369:Aged, 80 and over; D016887:Cardiopulmonary Resuscitation / Q000401:mortality*; D002947:Cities / Q000706:statistics & numerical data; D047548:Defibrillators / Q000706:statistics & numerical data*; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006297:Health Services Accessibility / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality* / Q000628:therapy*; D012111:Residence Characteristics
keywords: cardiopulmonary resuscitation; defibrillators; heart arrest; resuscitation