When your elderly neighbour collapses and has a cardiac arrest, you (should) know the drill: call EMS, start CPR & get an AED… faster is better. So does keeping an AED at home help? Read on…..

“Should I have an AED at home?”

It’s a question people on courses often ask. The commonest place for someone to have a cardiac arrest outside of hospital is at home. According to the Chain of Survival, early use of an AED is encouraged, so surely the best place to have one is right at home? As far as the Chain of Survival goes, after a cardiac arrest, faster is better, so having the device to hand must be the best answer? A collection of doctors in several countries set out to find the answer.

“Why does CPR change?”

Another common question – and the answer I give is that ‘people do research which causes changes to what we teach’. Here’s some of the research for you….
Doctors in seven countries took 7,000 patients at high risk for cardiac arrest. These people also had to have a spouse/companion who was willing & able to call EMS, do CPR and use an AED.
They were divided into two groups:

  • A. Video training for the partner on how to call EMS and do CPR
  • B. AED use (by the partner) along with the training above.

Then, the patients went home and carried on their normal activities.

Must be a no-brainer, right?

James tries CPR at age 4
So one group had a partner trained in CPR, one had a partner trained in CPR and AED use and was given an AED to use. The Chain of Survival says that early AED use increases the chances of survival, so it must be a no-brainer? Right? Surely the people with the AED at home had a better chance of survival?


  • Group A, 6.5% of people died (out of every 200 people, 13 died)
  • Group B, 6.4% of people died (out of every 200 people, err, well…. 13 died)

The difference is so small that it’s meaningless. There is effectively no difference at all. Let’s rephrase that:

Having an AED in your house, and someone trained to use it, makes no difference to your chance of survival!

So what happened?

Well, 450 people died
Two out of every three died from ‘unrelated problems’ that were not cardiac arrest
So only 1 in 3 would have benefited from the AED
Half of those collapsed and died without anyone around them. The partner, spouse or companion wasn’t there to call EMS and use the AED. The Chain of Survival can’t work if there’s no-one there to make it happen.
Just under half of those remaining had someone attempt CPR.

  • Most people didn’t need an AED.
  • Half of those who did, died alone without helpers.
  • One quarter who needed an AED got the help that was available.

Is there any good news?

Yes! (Hooray!) 18 people needed an AED, had someone to help, and an AED available. Six of them survived. Oh, and 4 of them weren’t study patients – people with access to an AED used it on neighbours too.
That may not seem huge, but without the training & AED it’s probable they would have all died. 33% survival is huge!

Chain of Survival

So what’s the take away message?

Follow the Chain of Survival. AEDs are great when they are needed and someone is trained to use them, they really do improve survival. But the chance of needing one, and having someone around to notice, get it and use it, is pretty small.
If you were thinking about buying an AED for grandma & grandpa, you might be better off spending the money on CPR training for the neighbours. At least that way there’s a better chance that they’ll be helped by someone who knows what to do.
Credits : A whole bunch of researchers, who sent their results to the New England Journal of Medicine. Oh, and me – for turning 13 pages of research into something I hope you understood! Use the comment box below for your questions.