To examine how automated external defibrillator (AED) placement and AED accessibility affect bystander defibrillation in out-of-hospital cardiac arrest (OHCA).
Materials and methods
We identified all OHCAs registered by the Copenhagen Mobile Emergency Care Unit physicians (2008-2016), and all publicly available AEDs in Copenhagen (2007-2016) from the Danish AED Network. All recorded OHCAs and AEDs were geocoded, and the route distances between OHCAs and AEDs were calculated. A covered OHCA was defined as an OHCA with an AED located ≤200m and AED accessibility was assessed for every AED at the exact time of OHCA. OHCA coverage loss according to type of AED location as well as likelihood of bystander defibrillation and 30-day survival were examined.
In total, 1,830 registered AEDs were identified. Of 2,500 OHCAs, 22.6% (n=566) were covered by an AED ≤200m route distance. However, due to limited AED accessibility at the time of OHCA, OHCA coverage loss ranged from 17%-72% depending on type of AED location. AEDs placed at companies/offices covered most OHCAs (n=105, 18.6%), followed by school/education facility (n=75, 13.3%), sports facility (n=73, 12.9%), and health clinics (n=71, 12.5%); and these AED locations had a coverage loss of OHCAs ˃50% as the AED was inaccessible at the time of OHCA. OHCAs covered by an accessible AED were more likely to receive bystander defibrillation (13.8 vs 4.8%, p<0.05) and achieve 30-day survival (29.1% vs 16.7%, p<0.05) compared with OHCAs near an inaccessible AED.
Bystander defibrillation is highly associated with AED placement and accessibility. OHCA patients covered by an accessible AED ≤200m were 3-fold more likely to receive bystander defibrillation and twice as likely to survive 30-days compared to OHCAs not covered by an accessible AED.