Hypothesis: First responder organizations with automated external defibrillators (AEDs) can have a larger impact on survival of out-of-hospital cardiac arrest than placing AEDs in large buildings.
Methods: To evaluate the impact, all cardiac arrests handled by a large urban fire department for 1994 were analyzed. Each 5.6 square mile area of the city was defined as business (Bus), high (HilRes), middle (MilRes), or low income (LoIRes) residential. For each area, the CPR rates were calculated for the number of arrests/100 ambulance dispatches, and were stratified by percent of adults over age 65.
Results: Of the 1,222 cardiac arrests, only 85 occurred in business and industrial areas, 1,041 occurred in residential areas. The downtown business district had only 77 arrests with half of those being outside of buildings or in shelters.