Nationwide public access defibrillation in Japan

[BACKGROUND]It is unclear whether dissemination of automated external defibrillators (AEDs) in public places can improve the rate of survival among patients who have had an out-of-hospital cardiac arrest. [METHODS]From January 1, 2005, through December 31, 2007, we conducted a prospective, population-based, observational study involving consecutive patients across Japan who had an out-of-hospital cardiac arrest and in whom resuscitation was attempted by emergency responders. We evaluated the effect of nationwide dissemination of public-access AEDs on the rate of survival after an out-of-hospital cardiac arrest. The primary outcome measure was the 1-month rate of survival with minimal neurologic impairment. A multivariate logistic-regression analysis was performed to assess factors associated with a good neurologic outcome. [RESULTS]A total of 312, 319 adults who had an out-of-hospital cardiac arrest were included in the study; 12, 631 of these patients had ventricular fibrillation and had an arrest that was of cardiac origin and that was witnessed by bystanders. In 462 of these patients (3.7%), shocks were administered by laypersons with the use of public-access AEDs, and the proportion increased, from 1.2% to 6.2%, as the number of public-access AEDs increased (P<0.001 for trend). Among all patients who had a bystander-witnessed arrest of cardiac origin and who had ventricular fibrillation, 14.4% were alive at 1 month with minimal neurologic impairment; among patients who received shocks from public-access AEDs, 31.6% were alive at 1 month with minimal neurologic impairment. Early defibrillation, regardless of the type of provider (bystander or emergency-medical-services personnel), was associated with a good neurologic outcome after a cardiac arrest with ventricular fibrillation (adjusted odds ratio per 1-minute increase in the time to administration of shock, 0.91; 95% confidence interval, 0.89 to 0.92; P