The Impact of Integrating Emergency Dispatch Systems with Public Automated External Defibrillator Locations: A Systematic Review of the Literature and an Original Research Study Design

Background: Out-of-hospital cardiac arrest, most commonly due to heart disease, kills as many as 450,000 people each year in the United States. Devices called automated external defibrillators can detect if this condition is due to an abnormal heart rhythm, and if so, can deliver a timed electrical shock. Though the use of defibrillators by the public is known to be both safe and effective, the impact of their integration into the 9-1-1 system remains unclear. Objective: To systematically review evidence on the effect that incorporating public defibrillator locations into the 9-1-1 dispatch system has on survival rates from out-of-hospital cardiac arrest, and to design a research study to evaluate this relationship. Methods: To systematically review the evidence, this author searched the MEDLINE, CINAHL, EMBASE, and The Cochrane Library (January 1, 2000 to May 1, 2011) using MeSH terms such as "automated external defibrillator" and "emergency medical services." Additional articles were identified through a bibliography search of selected articles. To design an original research study, this author used both the results of the systematic evidence review and previous studies conducted in the medical literature to specifically address public defibrillator integration. Results: The initial systematic review of the evidence yielded 128 citations. After review of the abstracts, 6 articles were identified for full text review. After applying inclusion and exclusion criteria, all of the articles were excluded. Manual review of two selected bibliographies revealed an additional article selected for a full text review; it was subsequently excluded. The systematic evidence review resulted in no articles meeting inclusion criteria for data analysis, leading this author to design a research study to answer the clinical question. The proposed study design is a multiphase before-after cohort occurring over 60 consecutive months in Orange County, NC. The study population includes all patients with out-of-hospital cardiac arrest from a cardiac etiology over 18 years of age treated by EMS. Phase 1 will serve as a lead-in period to bring the EMS agency up to full implementation of the 2005 AHA guidelines over 12 months. Phase 2 will be a baseline control period over 24 months. Phase 3 will serve as an intervention period with an integrated emergency dispatch system in addition to the 2005 AHA guidelines over 24 months. Primary outcome will be survival to discharge Conclusion: In the context of evaluating the impact that incorporating public defibrillator locations into the emergency dispatch system has on survival to discharge from out-of-hospital cardiac arrest, the medical literature suffers from a lack of evidence. The studies identified through the literature search did not completely address this issue; thusly, no inference can be made about causality at this time. Further research is required to determine the effect that an integrated 9-1-1 system has on survival.Master of Public Healt