Abstract 105: Rural-Urban Differences for Integrated First Responder and Drone Automated External Defibrillator Delivery in North Carolina

Abstract

Background: Early defibrillation for out-of-hospital cardiac arrest (OHCA) can improve survival significantly, but timely access to AEDs remains a barrier especially in rural areas. We analyzed whether differences exist between urban and rural areas for a proposed program of first responder (FR) and drone AED delivery in North Carolina. Methods: Using CARES registry data, we identified OHCAs in 48 counties between Jan. 2013-Dec. 2019. We applied a hypothetical intervention in which 1) all FRs were provided AEDs and 2) a network of AED-carrying drones was optimized within each county to maximize <5-minute response times (defined as the interval from 9-1-1 call receipt to arrival of an AED via EMS, FR, or drone). Within each county, we classified census tracts by rural population with <25% as urban, 25-75% as mixed, and >75% as rural. We included only counties with ≥10 OHCAs per year in both rural and urban census tracts to compare resource allocation for counties with large geographic variation. Historical and intervention response times stratified by rurality were compared via the Wilcoxon signed-rank test. Results: We included 19 counties and 8,955 OHCAs (5,754 urban, 3,201 rural). The historical median response time was 6.9 mins [IQR: 5.1-8.7] in urban census tracts and 9.4 mins [IQR: 7.0-12.1] in rural tracts. The FR + drone intervention reduced estimated median response times by 42% to 4.0 mins [IQR: 3.1-5.0] in urban areas and by 24% to 7.1 mins [IQR: 5.2-9.4] in rural areas. Five-minute coverage improved from 24% to 77% for urban areas and 10% to 23% for rural areas. All counties showed significant improvement in response time for both urban and rural populations (p<0.01). Conclusion: Deployment of AEDs by FR and drones optimized for 5-minute coverage was estimated to improve AED response more so in urban areas than rural areas. Other optimization parameters are needed to reduce inequality between urban and rural response times in areas with large geographic variation.