How many lives are saved by defibrillators in the UK?

There is no single UK figure showing exactly how many lives are saved by defibrillators alone.

Survival from an out-of-hospital cardiac arrest depends on several linked actions, including recognising cardiac arrest, calling 999, starting CPR, using a defibrillator as quickly as possible and receiving subsequent medical treatment.

However, UK evidence is very clear that early CPR and early use of an automated external defibrillator (AED) can substantially improve the chance of survival.

Resuscitation Council UK states that bystander CPR combined with use of an AED can increase the chance of surviving an out-of-hospital cardiac arrest by two to four times.

How Many Cardiac Arrests Occur in the UK Each Year?

Current Resuscitation Council UK figures estimate that approximately:

• 115,000 out-of-hospital cardiac arrests are reported to UK ambulance services each year;
• resuscitation is attempted in around 43,000 cases;
• overall 30-day survival is approximately 9–10%; and
• public-access AED use remains below 10% of cases.

Cardiac arrest outcomes vary across England, Scotland, Wales and Northern Ireland.

These figures demonstrate both the scale of the problem and the opportunity to improve survival through rapid CPR and defibrillation.

How Many Lives Were Saved in England?

The Out-of-Hospital Cardiac Arrest Outcomes (OHCAO) Registry provides detailed reporting for England.

Its 2024 overview recorded 2,738 people surviving to 30 days in the reported cohort.

The same report showed:

• 29,241 resuscitation attempts were recorded;
• 7,905 hearts were successfully restarted by ambulance service personnel;
• overall 30-day survival was 9.5%;
• survival in the Utstein comparator group was 29.0%; and
• 27.0% of patients were admitted to hospital with return of spontaneous circulation.

The report describes the 2,738 survivors as “lives saved”, but this should not be interpreted as 2,738 people saved specifically by public-access defibrillators.

Survival is the result of the complete chain of survival, including CPR, defibrillation, ambulance response and hospital care.

Why Can't We Say Exactly How Many People AEDs Save?

A cardiac arrest rarely involves just one intervention.

Someone may survive because:

1. a bystander recognised cardiac arrest;
2. 999 was called quickly;
3. CPR was started immediately;
4. an AED was retrieved;
5. the AED delivered an appropriate shock;
6. ambulance clinicians continued resuscitation; and
7. the patient received further treatment in hospital.

It is therefore difficult to separate the effect of the AED from every other part of the emergency response.

What research can show is that people have a much better chance of survival when CPR and defibrillation happen early.

How Much Difference Does an AED Make?

Resuscitation Council UK states that:

Bystander CPR and use of an AED increase the chance of survival from out-of-hospital cardiac arrest by two to four times.

That is one of the clearest reasons for making AEDs readily available in workplaces, schools, sports venues and community locations.

The time between collapse and defibrillation is particularly important when the person has a shockable heart rhythm.

Why Is Early Defibrillation So Important?

Some cardiac arrests begin with an electrical heart rhythm that can be treated using a defibrillator.

The sooner an appropriate shock is delivered, the greater the opportunity for successful resuscitation.

Resuscitation Council UK guidance highlights that the best chance of successful resuscitation occurs when CPR and defibrillation are delivered with minimum delay. Survival rates above 70% have been reported in some situations when defibrillation occurs within three minutes of collapse.

This does not mean every person shocked within three minutes will survive.

The outcome depends on factors including:

• the cause of the cardiac arrest;
• whether the collapse was witnessed;
• the person's initial heart rhythm;
• how quickly CPR begins;
• how quickly an AED is used; and
• the subsequent medical response.

What Does a Defibrillator Actually Do?

An automated external defibrillator analyses the electrical rhythm of the heart.

If it detects a rhythm suitable for defibrillation, the AED will either:

• advise the rescuer to deliver a shock; or
• deliver the shock automatically on a fully automatic model.

A defibrillator does not simply restart every stopped heart.

It treats specific abnormal electrical rhythms by delivering a controlled electrical shock.

You can read more in our guide:

Does a Defibrillator Restart a Stopped Heart?

Can Anyone Use a Defibrillator?

Yes.

Resuscitation Council UK states that anyone can use an AED.

Modern public-access defibrillators are designed to guide the rescuer with spoken and/or visual instructions.

You do not need to identify the heart rhythm yourself.

The AED does this automatically and determines whether a shock is appropriate.

Training can help increase confidence, but lack of previous AED training should not prevent someone from using one during a cardiac arrest.

How Often Are Public AEDs Actually Used?

Despite the benefits of early defibrillation, public AEDs are still used in only a small proportion of out-of-hospital cardiac arrests.

Current Resuscitation Council UK figures show bystander AED use rates of approximately:

• 9.0% in England;
• 10.3% in Scotland;
• 8.4% in Wales; and
• 8.0% in Northern Ireland based on the available 2025 reporting period.

This means that in the large majority of cardiac arrests, a public-access AED is not applied before the ambulance response.

Improving AED availability, accessibility and awareness therefore remains an important opportunity.

How Many Defibrillators Are Registered in the UK?

The UK has a national defibrillator network called The Circuit.

By mid-June 2025, Resuscitation Council UK reported:

• 108,584 registered AEDs; and
• 218,493 deployments or attempted deployments of Circuit-registered AEDs.

However, national data does not yet confirm how many of those deployments reached the casualty or resulted in AED use.

This is another reason why it is not possible to calculate a precise figure for the number of lives saved by public AEDs alone.

What Is The Circuit?

The Circuit is the national defibrillator network used by UK ambulance services.

When someone calls 999 during a suspected cardiac arrest, ambulance service staff can use The Circuit to identify registered defibrillators nearby.

This is why public-access AED owners should:

• register their AED;
• keep its location details accurate;
• confirm when it is emergency ready;
• keep accessibility information up to date; and
• update its status if pads, batteries or other consumables need replacing.

Why Accessibility Matters

Simply owning a defibrillator is not enough.

The device needs to be:

• easy to find;
• clearly signposted;
• accessible quickly;
• emergency ready; and
• known to ambulance services where it is publicly available.

Current Resuscitation Council UK guidance recommends that public-access AEDs should be:

• prominently signposted;
• stored in unlocked cabinets; and
• accessible 24 hours a day, seven days a week where possible.

An AED locked inside a building outside normal opening hours cannot help someone experiencing a cardiac arrest nearby.

Should My Workplace or Organisation Have a Defibrillator?

There is no general UK law requiring every workplace to provide an AED.

However, organisations can consider AED provision as part of their first-aid needs assessment.

Factors worth considering include:

• number of employees;
• number of visitors or members of the public;
• site size;
• location and accessibility;
• distance to existing AEDs;
• workforce demographics;
• physical activity carried out on site;
• distance from emergency medical help; and
• how quickly an AED could realistically reach a casualty.

Resuscitation Council UK provides risk-assessment guidance to help organisations consider whether AED provision is appropriate.

You can also use our:

Free Defibrillator Site Assessment Form

to help assess AED provision, location, accessibility and ongoing management.

Where Should a Defibrillator Be Located?

An AED should be positioned so that it can be found and retrieved quickly.

A suitable location should normally be:

• highly visible;
• clearly signposted;
• easy to access;
• known to staff;
• accessible during the periods people are present; and
• appropriate for the AED's environmental requirements.

For public-access installations, making the AED available outside normal building opening hours can increase its usefulness to the wider community.

Where an AED is installed outdoors, use a suitable AED cabinet designed to protect the device from environmental conditions.

What Should You Do if Someone Has a Cardiac Arrest?

If someone is unresponsive:

1. Call 999 as soon as possible.
2. Assess whether they are breathing normally while waiting for the call to be answered.
3. If they are unresponsive and not breathing normally, start CPR.
4. Send someone to retrieve an AED if one is available.
5. Switch the AED on.
6. Attach the electrode pads as shown.
7. Follow the AED instructions.
8. Continue CPR when instructed until professional help takes over.

This reflects current Resuscitation Council UK 2025 basic life support guidance.

For more information, read:

What Is CPR?

What Can Organisations Do to Improve the Chances of Survival?

Providing a defibrillator is only part of effective cardiac-arrest preparedness.

Organisations should also consider:

Install the AED in an Accessible Location

Avoid unnecessary barriers to retrieval.

Register Public-Access AEDs on The Circuit

This allows ambulance services to know where the AED is and when it is available.

Use Clear AED Signage

People need to be able to find the defibrillator quickly.

View AED Signs & Posters

Keep the AED Emergency Ready

Check pads, batteries, status indicators and accessibility regularly.

Our free AED Weekly Inspection Record can help organisations record routine readiness checks.

Consider CPR and AED Training

Training can improve familiarity and confidence in responding to an emergency.

View CPR Training Manikins

View AED Trainers

Frequently Asked Questions

How many lives do defibrillators save each year in the UK?

There is no reliable national figure showing how many people are saved specifically by defibrillators alone.

Current UK data shows that around 43,000 out-of-hospital cardiac arrests receive attempted resuscitation each year, with overall 30-day survival of approximately 9–10%.

How many people survive cardiac arrest in the UK?

Survival varies by nation and circumstances.

Overall 30-day survival after out-of-hospital cardiac arrest is approximately 9–10%, while survival is significantly higher in the subgroup where the arrest is witnessed and the initial rhythm is shockable.

How many lives were saved in England in 2024?

The OHCAO 2024 England overview reports 2,738 30-day survivors in the cohort for which data was submitted.

This figure represents overall survival following resuscitation and should not be interpreted as the number saved by public defibrillators alone.

Does using a defibrillator increase survival?

Yes.

Resuscitation Council UK states that bystander CPR and use of an AED can increase the chances of survival by two to four times.

Can anyone use an AED?

Yes.

Modern AEDs analyse the heart rhythm automatically and provide instructions to the rescuer.

Are defibrillators used often enough in the UK?

No. Current UK data shows public or bystander AED use remains below 10% of out-of-hospital cardiac arrests.

Should a public defibrillator be registered?

Yes. Public-access AEDs should be registered on The Circuit so ambulance services can locate them during an emergency.

Help Make Early Defibrillation Possible

There may be no single figure showing exactly how many UK lives are saved by defibrillators each year, but the evidence is clear:

• early CPR and early defibrillation can significantly improve a person's chances of surviving cardiac arrest.

For organisations considering AED provision, Risk Assessment Products supplies:

Defibrillators & AEDs – AEDs from leading manufacturers.
AED Cabinets & Cases – indoor and outdoor AED storage.
AED Signs & Posters – signage to help people locate an AED quickly.
Free Defibrillator Site Assessment Form – assess AED provision and location.
Free AED Weekly Inspection Record – help keep your AED emergency ready.

If you are unsure which defibrillator is suitable for your workplace, school or organisation, contact Risk Assessment Products for product advice.