Alert system-supported lay defibrillation and basic life-support for cardiac arrest at home.

BACKGROUND Automated external defibrillators (AEDs) are placed in public, but the majority of out-of-hospital cardiac arrests (OHCA) occur at home. METHODS In residential areas 785 AEDs were placed and 5735 volunteer responders recruited. For suspected OHCA, dispatchers activated nearby volunteer responders with text messages, directing two-thirds to an AED first and one-third directly to the patient. We analyzed survival (primary outcome) and neurologically favorable survival to discharge, time to first defibrillation shock and cardiopulmonary resuscitation (CPR) before Emergency Medical Service (EMS) arrival of patients in residences found with ventricular fibrillation (VF), before and after introduction of this text-message alert system. RESULTS Survival from OHCAs in residences increased from 26% to 39% [adjusted relative risk (RR) 1.5 (95% CI 1.03-2.0)]. RR for neurologically favorable survival was 1.4 (95% CI 0.99 - 2.0). No CPR before ambulance arrival decreased from 22% to 9% (RR 0.5, 95% CI 0.3 - 0.7). Text-message-responders with AED administered shocks to 16% of all patients in VF in residences, while defibrillation by EMS decreased from 73% to 39% in residences (p < 0.001). Defibrillation by first responders in residences increased from 22% to 40% (p < 0.001). Use of public AEDs in residences remained unchanged (6% and 5%) (p = 0.81). Time from emergency call to defibrillation decreased from median 11.7 min to 9.3 min; mean difference -2.6 (95% CI -3.5 - -1.6). CONCLUSION Introducing volunteer responders directed to AEDs, dispatched by text-message was associated with significantly reduced time to first defibrillation, increased bystander CPR and increased overall survival for OHCA patients in residences found with VF.