Abstract 12337: Modeled Geographic Optimization of Public Access Defibrillator Locations
Introduction: Mortality after out-of-hospital cardiac arrest (OHCA) is very high. Early defibrillation improves chances of survival. Bystanders rarely use automated external defibrillators (AEDs).
Hypothesis: Current geographical deployment of AEDs in the Toronto and Peel Regions of Ontario can be improved using optimization techniques.
Objectives: 1) Quantify the current coverage of historical OHCAs with registered AEDs; 2) Develop a strategy to optimize future AED placement using mathematical modeling techniques.
Methods: The Resuscitation Outcomes Consortium Epistry — Cardiac Arrest is a large epidemiologic registry of consecutive OHCAs. To assess the current deployment of public access AEDs registered with emergency medical dispatch, we measured distance and time metrics relative to public location cardiac arrests in our study region occurring between 01/01/2006 and 11/30/2009. Using geographic information systems technology and the maximal covering location model, we determined optimal locations for the placement of future AEDs.
Results: We analyzed 1,414 public-location out-of-hospital cardiac arrests. There were 2,041 pre-existing registered AEDs providing coverage (within 100 meters) for only 226 of these episodes (16.0%). The average distance to the closest AED was 487 ± 779 meters. The average bystander travel time to the closest AED was 4.87 ± 7.79 minutes (walking at 100 m/minute). Using our optimization model, we determined that the top five locations for additional AED placement would cover an additional 51 OHCAs. A minimum of 884 additional AEDs would be required to cover all historical public location OHCAs with sequential priority placement of AEDs resulting in one-to-one coverage after approximately 200 new AEDs (Figure 1).
Conclusions: Distribution of registered AEDs in the study region is sub-optimal. Modeling has the potential to improve AED distribution, usage and survival after public location OHCA.
- © 2010 by American Heart Association, Inc.