Walking time to nearest public automated external defibrillator for out-of-hospital cardiac arrest in a major U.S. city.

Background: How frequently out-of-hospital cardiac arrest (OHCA) occurs within a reasonable walking distance to the nearest public automated external defibrillator (AED) has not been well studied. Methods: As Kansas City, Missouri has a comprehensive city-wide public AED registry, we identified adults with an OHCA in Kansas City during 2019-2022 in the Cardiac Arrest Registry to Enhance Survival. Using AED location data from the registry, we computed walking times between OHCAs and the nearest registered AED using the Haversine formula, a mapping algorithm to calculate walking distance in miles from one location to another. Results were stratified by OHCA location (home vs. public) and by whether the patient received bystander cardiopulmonary resuscitation (CPR). Results: Of 1,522 OHCAs, 1,291 (84.8%) occurred at home and 231 (15.2%) in public. Among at-home OHCAs, 634 (49.1%) received bystander CPR and no patients had an AED applied even as 297 (23.0%) were within a 4-minute walk to the closest public AED. Among OHCAs in public, 108 (46.8%) were within a 4-minute walk to the closest public AED. For public OHCAs within a 4-minute walk, bystanders applied an AED in 13 (12.0%) of these cases and in 24.5% (13/53) of those who received bystander CPR. Conclusion: In one U.S. city with a publicly available AED registry, there were no instances in which a bystander accessed a public AED for an OHCA at home. For OHCAs in public, nearly half occurred within a 4-minute walk to the closest AED but bystander use of an AED was low.