Effect of Out-of-Hospital Defibrillation by Basic Life Support Providers on Cardiac Arrest Mortality: A Metaanalysis, , ,

See related editorial, "Effectiveness of Basic Life Support Defibrillation." Study objective: Although some studies demonstrate otherwise, we hypothesized that metaanalysis would demonstrate a reduction in the relative risk of mortality when basic life support (BLS) providers can defibrillate out-of-hospital cardiac arrest patients. Design: Metaanalysis of studies meeting the following criteria: single-tier or two-tier emergency medical service (EMS) system, survival to hospital discharge for patients in ventricular fibrillation, and manual and/or automatic external defibrillators. The aerror rate was .05. Results: Seven trials qualified for metaanalysis. Across all trials, the risk of mortality for BLS care with defibrillation versus that without was .915 (P =.0003). Separate subset analyses of single-tier and two-tier EMS systems demonstrated similar results. Conclusion: BLS defibrillation can reduce the relative risk of death for out-of-hospital cardiac arrest victims in ventricular fibrillation. Weaknesses in individual study designs and regional clustering limit the strength of this metaanalysis and conclusion.