Automated external defibrillator accessibility is crucial for bystander defibrillation and survival: A registry-based study

Abstract

AimsOptimization of automated external defibrillator (AED) placement and accessibility are warranted. We examined the associations between AED accessibility, at the time of an out-of-hospital cardiac arrest (OHCA), bystander defibrillation, and 30-day survival, as well as AED coverage according to AED locations. MethodsIn this registry-based study we identified all OHCAs registered by mobile emergency care units in Copenhagen, Denmark (2008–2016). Information regarding registered AEDs (2007–2016) was retrieved from the nationwide Danish AED Network. We calculated AED coverage (AEDs located ≤200 m route distance from an OHCA) and, according to AED accessibility, the likelihoods of bystander defibrillation and 30-day survival. ResultsOf 2500 OHCAs, 22.6% (n = 566) were covered by a registered AED. At the time of OHCA, <50% of these AEDs were accessible (n = 276). OHCAs covered by an accessible AED were nearly three times more likely to receive bystander defibrillation (accessible: 13.8% vs. inaccessible: 4.8%, p < 0.001) and twice as likely to achieve 30-day survival (accessible: 28.8% vs. inaccessible: 16.4%, p < 0.001). Among bystander-witnessed OHCAs with shockable heart rhythms (accessible vs. inaccessible AEDs), bystander defibrillation rates were 39.8% vs. 20.3% (p = 0.01) and 30-day survival rates were 72.7% vs. 44.1% (p < 0.001). Most OHCAs were covered by AEDs at offices (18.6%), schools (13.3%), and sports facilities (12.9%), each with a coverage loss >50%, due to limited AED accessibility. ConclusionsThe chance of a bystander defibrillation was tripled, and 30-day survival nearly doubled, when the nearest AED was accessible, compared to inaccessible, at the time of OHCA, underscoring the importance of unhindered AED accessibility.