App alerts heroes: volunteers with defibrillators rush to cardiac arrests
NCT ID NCT03835403
First seen Jun 27, 2026 · Last updated Jun 27, 2026
Summary
This study tested whether using a smartphone app to alert nearby volunteers (called 'heart runners') to bring an automated external defibrillator (AED) to a suspected cardiac arrest can improve survival. Over 2,000 emergency calls were randomly assigned to either activate these volunteers or provide standard emergency medical services alone. The main goal was to see if more patients were alive 30 days later, and the study also checked for any harm to the volunteers.
What this could mean
Our plain-language read of the trial. This is informational only — not medical advice or a prediction.
Active substance
Smartphone app activation of volunteer citizen first-responders with AEDs
What this could lead to
If successful, this approach could significantly increase survival rates for out-of-hospital cardiac arrest by getting defibrillators to patients faster.
What could go wrong
The trial is completed but results may show no survival benefit, and there are risks of psychological or physical harm to volunteer responders.
Disclaimer
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This is a summary of
the original study
.
Summaries may miss details or leave out important information. Before applying or accepting participation, make sure you have read and understood the full study. Curemydisease.com takes no responsibility whatsoever for anything missed, misunderstood, or acted upon as a result of our summary — we know it does not capture everything.
This is a summary of the original study . Summaries may miss details or leave out important information. Before applying or accepting participation, make sure you have read and understood the full study. Curemydisease.com takes no responsibility whatsoever for anything missed, misunderstood, or acted upon as a result of our summary — we know it does not capture everything.
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
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Locations
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Emergency Medical Services Copenhagen
Copenhagen, Ballerup, Denmark