Abstract 146: Modeling the Impact of AED Range on Cardiac Arrest Coverage
Background: Public access defibrillation with automated external defibrillators (AEDs) can improve survival from out-of-hospital cardiac arrest (OHCA). Increasing the effective range of AEDs may improve overall OHCA coverage.
Objective: To quantify the improvement potential in cardiac arrest coverage as a function of AED coverage radius.
Methods: This was a retrospective cohort study using the Resuscitation Outcomes Consortium Epistry database. We included all public-location, atraumatic, EMS-attended OHCAs in Toronto, Canada between Dec. 15, 2005 and July 1, 2010. We ran a geographic optimization model for AED deployment that maximizes coverage of historical OHCAs given pre-specified values of AED coverage radius and the number of locations to deploy AEDs. A set of 25,851 public buildings obtained from the City of Toronto were used as candidate sites for AED placement. Coverage was evaluated for radius values from 10 to 300 meters and number of AED locations from 10 to 200, both in increments of 10, for a total of 600 unique scenarios. Coverage from placing AEDs in all 25,851 public buildings was also evaluated at each radius.
Results: There were 1,310 public location OHCAs during the study period. Figure 1 shows cardiac arrest coverage for up to 200 optimally located AEDs as well as from placing AEDs in all public buildings. Diminishing returns were observed as AED radius increased. For example, with 200 AEDs, increasing radius from 50m to 100m covered an additional 12.8% of all cardiac arrests, whereas increasing radius from 250m to 300m only covered an additional 5.3%. The largest gains in coverage were attained at low AED radii.
Conclusion: Increasing AED range can improve cardiac arrest coverage. Geographic optimization models can help evaluate the potential impact of initiatives to increase AED range.
Figure 1: Cardiac arrest coverage for AED range between 0 and 300 meters
- © 2012 by American Heart Association, Inc.