Abstract 337: Bystander Defibrillation in High Risk Neighborhoods

Abstract

Background: Whether public health efforts successfully prioritize bystander automated external defibrillator (AED) application in areas with highest of hospital cardiac arrest (OHCA) burden is unknown. Methods: Within the Cardiac Arrest Registry to Enhance Survival, we identified all adult, public OHCAs linked to a census tract between 2013- 2021. We ranked all census tracts by annual public OHCA volume to ascertain relative burden, then assessed the association of census tract OHCA burden and bystander AED application rate (application prior to emergency personnel arrival), using a hierarchical modified poisson regression model, to account for clustering within tracts, and arrest characteristics. Results: Among 25,787 tracts with 90,898 public OHCAs, the mean (SD) age was 57.1 (16.0) years, with 70,900 (78.0%) male and 45,388 (49.9%) White victims. Overall, bystander AED application rates were low (10.9%). There was a modest association between neighborhood OHCA burden and bystander AED application rates (ρ=0.243). After adjustment, neighborhoods with the highest OHCA burden (>2/ year) had a higher relative risk of bystander AED application than those with lowest burden (<1/ every other year) (RR 2.07; 95% CI 1.95, 2.20, p<.0001). However, this was due to a small proportion of high performing communities, as 700/1145 (61.1%) of highest OHCA burden communities had a bystander AED application rate less than the overall mean, 10.9%. Conclusion: High OHCA burdened areas have increased odds of bystander AED application, however this is driven by a few high performing neighborhoods. Targeted, context informed strategies are necessary to improve application rates and survival for the majority of high-risk neighborhoods.