AP-452680-2 GEOSPATIAL ANALYSIS OF BYSTANDER-INITIATED AUTOMATED EXTERNAL DEFIBRILLATOR UTILIZATION IN A LARGE US COMMUNITY

Abstract

Bystander use of automated external defibrillators (AED) can improve survival from out-of-hospital sudden cardiac arrest (SCA), but utilization can be variable. We hypothesized that AED distribution and utilization is determined by race/ethnicity and socioeconomic status of neighborhoods. To evaluate the distribution and utilization of bystander-initiated AED use for SCA events in a single large US community. All consecutive SCA cases with resuscitation attempted by emergency medical services (EMS) in Ventura County, CA (pop. 848,112, 43% Hispanic) were prospectively identified during 2015-2022. AED locations were obtained from the Ventura County Healthcare Agency Registry. Census tracts in the county (US Census 2018 estimates), were dichotomized as above or below the median census tract household income categorized as SES1 (income <median income) and SES2 (income >median income). AED and SCA event locations were geocoded and merged with the 2018 census tract geospatial map. The Euclidean distance (meters) between these two locations was calculated. AEDs were considered in viable proximity if located within 300 meters of the SCA event. Differences were analyzed using univariate statistical methods. Among 2515 cases (70.5±16.33 y, 65% male) of whom 684 (27%) were Hispanic, 782 (31%) were in viable proximity of an AED (Figure). There were no ethnicity-based differences in viable AED proximity (Hispanic n= 225(33%), non-Hispanic n=557 (30%), p=0.23). A total of 1442 (57%) cases (70±16.17 y, 65% male) were categorized as SES1 and 1070 (43%) cases (71±16.52 y, 65% male) as SES2. No significant differences in viable AED proximity were identified between SES1 (n= 434, 30%), and SES2 (n=348(33%); p=0.19). A total of 1361(54%) received bystander CPR, but bystander-initiated AED use was observed in 75 (3%). AED use was observed in 75/782 (9%) SCA cases in viable proximity to an AED of whom 3.1% were Hispanic and 12.2% non-Hispanic (p <0.001). SES2 cases had higher AED utilization than SES1 cases (12.4% vs. 7.8%, p = 0.02). In this western US community, AEDs in viable proximity to SCA events were distributed equitably, and not affected by neighborhood SES or ethnicity. However, bystander-initiated use for AEDs in close proximity was under 10%, indicating significant missed opportunities. These findings highlight the critical need to enhance community-wide education in bystander-initiated CPR and AED use for further improvement in SCA survival outcomes.