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What the survival numbers actually say
Roughly one in ten survives an out-of-hospital cardiac arrest, and the spread between towns is wider than the spread between treatments. How to read the statistics without being misled by them.
CPR in sixty seconds
- Unresponsive and not breathing normally? Gasping is not breathing. Treat it as a cardiac arrest.
- Call 112 (113 in Norway). Speaker on, phone on the floor. Stay on the line — the dispatcher will coach you.
- Push hard and fast in the centre of the chest: 5–6 cm in an adult, 100–120 per minute, letting the chest come all the way back up.
- Send somebody else for a defibrillator. Do not go yourself unless it is seconds away. Keep compressing.
- Turn the device on and do what it says. It decides whether to shock. After a shock, go straight back to compressions.
This is a reference written for bystanders, not a diagnosis, a training course or medical advice. It cannot tell you what is wrong with a particular person, and it does not replace the dispatcher on the other end of an emergency call — they can see what is near you and they will talk you through it. If you are worried about your own heart, or about a symptom, that is a conversation with a clinician rather than a page on a website.
The headline number and why it is misleading
Across European registry work, survival to hospital discharge after an out-of-hospital cardiac arrest that emergency services attempt to treat sits in the region of one in ten, with a very wide spread between countries and between cities within a country. That figure is quoted so often that it reads as a property of cardiac arrest. It is not: it is an average across wildly different situations, from an unwitnessed arrest found cold in the morning to a witnessed collapse in a sports hall with a defibrillator on the wall.
Three variables do most of the work
Was it witnessed. Was the first rhythm shockable. How long until compressions and a shock. A witnessed collapse in ventricular fibrillation, with immediate bystander CPR and a defibrillator within a few minutes, has a survival rate several times the average — in the best documented settings, such as arrests in airports, casinos and sports facilities with on-site devices, a majority of such patients have survived. An unwitnessed arrest found in asystole is at the other end and no amount of ambulance quality changes it.
Why the spread between places is the real story
Neighbouring regions with the same hospitals and the same ambulances can differ several-fold in survival, and the difference tracks bystander behaviour and system design rather than medicine: how many people start CPR, how quickly a dispatcher recognises the arrest by phone, whether volunteer responders are alerted, whether the devices near the patient are registered so the dispatcher can see them. Those are all things a municipality, an employer or a sports club can change.
Reading a claim critically
Whenever you see a survival figure, ask what the denominator is. Survival of all arrests, of arrests where resuscitation was attempted, of witnessed arrests, or of witnessed shockable arrests are four very different numbers and marketing material tends to quote the most flattering one. Ask also whether the outcome is a pulse on arrival at hospital, survival to discharge, or survival with good neurological function — the last of these is the one that matters and it is always the lowest.
What this means for one person deciding what to do
The practical translation is short. If you do nothing, the outcome is near-certain. If you push on the chest, the odds improve by a factor of two or three. If you or somebody else can get a defibrillator onto the chest in the first few minutes and the rhythm is shockable, the odds improve dramatically again. None of that requires you to be right about the diagnosis, skilled, or calm.
Sources: European Resuscitation Council Guidelines · International Liaison Committee on Resuscitation (ILCOR) · checked 2026-09-08
Frequently asked questions
How many people survive a cardiac arrest outside hospital?
Roughly one in ten of the arrests emergency services treat, on European averages, with a wide spread between systems. Witnessed arrests with a shockable rhythm and fast defibrillation do far better than that.
Does every minute really cost ten per cent?
That is the widely used approximation for the fall in survival per minute without CPR or defibrillation. Good bystander CPR substantially flattens the curve, which is why compressions matter even while you wait for a device.
Why do neighbouring regions have such different survival?
Because bystander behaviour and system design differ more than medicine does — how many people start CPR, how fast dispatchers recognise arrest, whether volunteer responders exist, and whether nearby defibrillators are registered.
How the system around it works
The chain of survival, link by link
Recognition and a call, early CPR, early defibrillation, advanced care and recovery. What each link is actually worth, which one the public owns, and where the chain breaks in practice.
National registers, and getting your device into one
A defibrillator the dispatcher cannot see barely exists. What a national register is, which one is the real one in each country, why registration is free, and the paid look-alikes to avoid.
Volunteer responder systems
Denmark, Sweden and Norway alert trained volunteers by phone to arrests near them — one to fetch the defibrillator, one to start compressions. How the systems work, who can join, and what happens when your phone goes off.
Where public defibrillators actually are
The green sign with the heart and the lightning bolt, the places that reliably have one, the cabinets that are locked and the ones that are not, and what to do when you have thirty seconds to decide whether to go looking.
What a defibrillator costs to buy and to keep
The purchase is the small part. Pads and batteries expire on a schedule, cabinets and signage cost real money in a cold climate, and the recurring line is what an organisation forgets to budget for.
Everything on this subject
Before the emergency, there is a long quiet stretch
Blood pressure, resting heart rate, movement and sleep are the part of this you can act on for years beforehand. TempoLife keeps them in one place, free to start.