Automated External Defibrillator Availability, Accessibility, and Usability in High-Risk Out-of-Hospital Cardiac Arrest Neighborhoods of Birmingham, Alabama

BACKGROUND: Automated external defibrillators (AEDs) are rarely used by bystanders in Birmingham, Alabama. We sought to characterize AED availability, accessibility, and usability in the highest-risk out-of-hospital cardiac arrest neighborhoods of Birmingham. METHODS: We conducted a descriptive observational study from June 12 to August 27, 2025, in 3 Birmingham neighborhoods with the highest relative out-of-hospital cardiac arrest risk. Potential public AED sites, defined as properties other than single-family residences, were identified using Google Maps landmark descriptions. Sites were contacted by telephone, email, or in person to confirm AED presence, and device-specific data were collected in person. Outcomes included AED availability (presence of ≥1 AED), accessibility (public access and hours), and usability (ability to power on with pads). At-risk devices contained expired batteries and pads. Observed and effective AED densities were compared with the recommended 5 AEDs per square mile. Observed AED density was defined as AEDs per square mile, regardless of accessibility hours. Effective AED density was defined as AEDs per square mile adjusted for weekly hours of accessibility. RESULTS: A total of 287 potential AED locations were identified, and 284 (99%) were contacted and provided data. Fifty-six AEDs were reported at 43 locations (15.1%). Of these, 19 (33.9%) were not publicly accessible. Among the 37 publicly accessible AEDs, none were available 24 hours per day. Thirty-five (94.6%) were found in usable condition, and 5 (13.5%) were classified as at risk. Two (5.4%) were inoperable. The observed density of publicly usable AEDs was 13.5 AEDs per square mile, with an effective density of 3.7 AEDs per square mile due to limited hours of access. CONCLUSIONS: Despite exceeding the recommended AED density, limited public accessibility and maintenance issues substantially reduce effective AED coverage in Birmingham. Reporting effective AED density, which accounts for hours of access, reveals gaps between device presence and real-world accessibility.