Mobile Smartphone Technology Is Associated With Out-of-hospital Cardiac Arrest Survival Improvement: The First Year "Greater Paris Fire Brigade" Experience.

Background: Out-of-hospital cardiac arrest (OHCA) remains associated with very high mortality. Accelerating the initiation of efficient cardiopulmonary resuscitation (CPR) is widely perceived as key to improving outcomes. The main goal was to determine whether identification and activation of nearby first responders through a smartphone application named Staying Alive (SA) can improve survival following OHCA in a large urban area (Paris).