Impact of AEDs and training of smartphone activated volunteers in residential areas on OHCA: a nationwide stepped-wedge implementation trial.
Resuscitation · 2025-09-12 · Quasi-experimental
Abstract
BACKGROUND: Early bystander interventions can improve out-of-hospital cardiac arrest (OHCA) survival rates. We hypothesized that an interventional bundle including automated external defibrillator (AED) installation in residential areas and training smartphone activated volunteers would increase bystander intervention and survival rates. METHODS: We conducted a stepped-wedge cluster non-randomized study between 1 April 2010 and 31 December 2020 in Singapore. AEDs were installed sequentially over eight "wedges", with one AED installed at every two housing blocks. Cardiopulmonary resuscitation (CPR)/AED training was conducted for residents including enrolling them as smartphone activated volunteers. Primary outcome was bystander AED application. Secondary outcomes were bystander CPR application, prehospital return of spontaneous circulation (ROSC), survival to discharge/30th day/with favorable neurological function. Using generalized estimating equation, we compared outcomes between intervention and control groups, accounting for clustering effects and confounders. A stratified analysis by location of arrest was also conducted. RESULTS: 18,086 OHCAs were analysed (Intervention: n = 8,180; Control: n = 9,906). We found increased odds of bystander AED application in the intervention compared to control group (aOR 3.94 [95 %CI 3.28, 4.74]; p < 0.05). The effect of the intervention on bystander AED application was greater for OHCAs occurring in residential (aOR 10.31 [95 %CI 6.94, 15.33]) than those in public locations (aOR 2.84 [95 %CI 2.24, 3.59]). CONCLUSIONS: The implementation of AED installation in residential areas and training of smartphone activated volunteers increased bystander AED application; the impact was higher for OHCAs occurring in residential compared to public locations. This may be a promising strategy for increasing bystander AED use in densely populated residential areas.