This is a study of a comprehensive, integrated community approach in which volunteer non-medical responders (lay volunteers without a traditional responsibility to take charge) are trained to use automated external defibrillators (AEDs). This approach is called Public Access Defibrillation (PAD). The hypothesis to be tested is that PAD will significantly increase survival in OOH-CA by reducing the time interval from collapse to defibrillation. The specific aim of this randomized, controlled trial is to measure survival to hospital discharge following OOH-CA in community units trained and equipped to provide PAD, compared to community units trained to provide standard care (recognition of OOH-CA, 911 access, cardiopulmonary resuscitation [CPR]).

Participating research sites have identified 1000 distinct units (e.g., public areas, gated communities, shopping malls, airport terminals, casinos, business parks) within their service area that contain a stable population of at least 250 people aged 50 years or greater. Following preliminary data collection, each unit will be randomized to serve as either an intervention or control group. At each site, each unit will be sub-randomized to a retraining stategy/interval. Performance at retraining will be monitored, and longer intervals decreased, if indicated.

Volunteer non-medical responders (e.g., office staff, bank tellers, merchants, and neighborhood volunteers) in both the intervention and control groups will be trained to: a) recognize OOH-CA, b) access 911 or its equivalent, and c) administer CPR. Non-medical responders in the intervention group will also be taught to use an AED promptly while awaiting arrival of the first public safety emergency medical team. The criteria for number and location of trained volunteers and devices will be a maximum 3-minute "walk through" to deliver the AED to the OOH-CA victim.

OOH-CA victims in each of the two groups will be compared with respect to their: a) survival to hospital discharge (Utstein criteria); b) neurological status, c) quality of life, and d) resource use/costs. The incremental cost-effectiveness of volunteer non-medical responder defibrillation will be calculated.

This study will allow us to develop informed public policy regarding the use of AEDs by volunteer non-medical persons.