In the UK fewer than 10% of all the people in whom a resuscitation attempt is made outside the hospital survive. Improving this figure is a major priority for Resuscitation Council UK, the Department of Health and Social Care, ambulance services and first aid organisations.
When all the stages in the Chain of Survival take place promptly, the figures are very much better. This is possible where the arrest is recognised immediately, bystanders perform CPR, and an automated defibrillator is used before the ambulance service arrive. Survival rates in excess of 50% have been reported under these circumstances.