Public access defibrillators (PADs) are disproportionately lacking in the most deprived areas of England, which are among the communities at the greatest risk of cardiac arrest, according to a new analysis led by NIHR-funded researchers.
Using information from ambulances services in England on defibrillators that have been registered with them, researchers from the University of Warwick have also found that fewer defibrillators are installed in residential areas – at locations such as outside community halls and primary schools – where cardiac arrests are most likely to occur.
Many, but not all, defibrillators are registered with ambulance services. A registered defibrillator is more likely to be used because when a member of the public calls 999 in an emergency the call operator can direct them to the nearest one.
The researchers used data from 10 of the 11* ambulance services in England on registered defibrillators in their areas and combined this with information from the Office for National Statistics on the characteristics of the population in those areas, such as ethnic backgrounds, education level and types of employment.
They also used the Index of Multiple Deprivation, which is the official measure of relative deprivation for small areas - or neighbourhoods - in England.
This allowed the researchers to establish an overall picture of the distribution of registered defibrillators in England, which revealed that more deprived areas tended to have the lowest number of defibrillators. Only 27.4% of areas in the lowest decile of the Index of Multiple Deprivation had at least one defibrillator, compared to about 45% in the highest.
Defibrillators are more likely to be placed in areas where people are likely to work rather than residential areas. Areas with a larger proportion of the population that identified themselves from mixed and non-white ethnic background were also less likely to have a registered defibrillator.
However, because there is no legal requirement to register a defibrillator with an ambulance service, there is uncertainty around the number of unregistered ones in these communities. As 999 call operators would not know the location of the nearest defibrillator in an emergency, it means those communities will be experiencing a health inequality compared to less deprived areas.
Lead author of the study, Dr Terry Brown from Warwick Clinical Trials Unit, said: “We know that cardiac arrests occur more often in deprived areas, but registered defibrillators are more likely to be found in areas where the population is more affluent, predominantly identify as white ethnic, and with high socio-economic occupations. The question is whether this is because they’re not registered in more deprived areas, or because there aren’t any?
“We want to get more defibrillators registered. Any future programme that aims to get defibrillators out there should be targeted to the areas that need them most. In particular, they should be put in more deprived communities, and in accessible locations in residential areas given that more than 80% of out of hospital cardiac arrests happen in the home. There should be a more evidence-based distribution programme to ensure they are accessible.
“If they are registered, more easily accessible, and people had the confidence to use them, we believe there will be an improvement in survival rates from cardiac arrest.”
Professor Melanie Davies, Director of the NIHR Leicester Biomedical Research Centre, said: “Evidence shows that access to public defibrillators vastly improves the chances of surviving life-threatening cardiac arrests.
“Central to NIHR’s mission is to tackle health inequalities and their wider determinants. That’s why it’s important this high quality research has cast a light on the gap in provision of defibrillators in some of the most deprived areas and in residential areas. These findings provide robust evidence in another step to help improve the quality and accessibility of health services.”
The study was funded by the NIHR’s Health and Social Care Delivery Research (HSDR) Programme and supported by the NIHR Applied Research Collaboration (ARC) West Midlands.
More information is on the PAD-OP study’s project page.
* Data from one ambulance service was not available at time of analysis.