Analysis of out-of-hospital cardiac arrest location and public access defibrillator placement in Metropolitan Phoenix, Arizona

Objectives: Automated external defibrillators (AEDs) improve outcomes from out-of-hospital cardiac arrest (OHCA) but are infrequently used. We sought to compare the locations of OHCAs and AEDs in metropolitan Phoenix, Arizona. Methods: Public location OHCAs and AEDs were geocoded utilizing a statewide OHCA database (1/2010-12/2012) and AED registry. OHCAs were mapped using kernel-density estimation and overlapped with AED placements. Spearman's rho was obtained to determine the correlation between OHCA incidents and AED locations. Results: A total of 654 consecutive public location OHCAs and all 1704 non-medical facility AEDs registered in the study area were included in the analysis. High OHCA incident areas lacking AEDs were identified in the kernel-density surface map. OHCA event/AED correlation analysis showed a weak correlation (Spearman's rho. =. 0.283; p=. 0.002). Events occurred most frequently at locations categorized as "In Cars/Roads/Parking lots" (190/654, 29.1%) and there were no identified AEDs for these areas. AEDs were placed most frequently in "Public business/Office/Workplace" and cardiac arrests occurred with the second highest frequency in this location type. Conclusion: There was a weak correlation between OHCA events and deployed AEDs. It was possible to identify areas where OHCAs occurred frequently but AEDs were lacking. The ability to correlate the sites of OHCAs and AED locations is a necessary step toward improving the effectiveness of public access defibrillation.