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Abstract
Introduction Growing numbers of public access defibrillators aim to improve the effectiveness of bystander cardiopulmonary resuscitation prior to ambulance arrival. In the UK, however, public access defibrillators are only deployed successfully in 1.7% of out-of-hospital cardiac arrests. We aimed to understand whether this was due to a lack of devices, lack of awareness of their location or a reflection of lack of public knowledge and confidence to use a defibrillator.
Methods Face-to-face semistructured open quantitative questionnaire delivered in a busy urban shopping centre, to identify public knowledge relating to public access defibrillation.
Results 1004 members of the public aged 9–90 years completed the survey. 61.1% had been first aid trained to a basic life support level. 69.3% claimed to know what an automatic external defibrillator was and 26.1% reported knowing how to use one. Only 5.1% knew where or how to find their nearest public access defibrillator. Only 3.3% of people would attempt to locate a defibrillator in a cardiac arrest situation, and even fewer (2.1%) would actually retrieve and use the device.
Conclusions These findings suggest that a lack of public knowledge, confidence in using a defibrillator and the inability to locate a nearby device may be more important than a lack of defibrillators themselves. Underused public access defibrillation is a missed opportunity to save lives, and improving this link in the chain of survival may require these issues to be addressed ahead of investing more funds in actual defibrillator installation.
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Introduction
For the 30 000 individuals suffering a sudden out-of-hospital (OOH) cardiac arrest in the UK each year where attempts at resuscitation are appropriate,2 survival is poor, with current rates averaging no more than 7–10%.3 Many of these events are potentially survivable, as evidenced by the best systems of care that achieve comparable survival rates in excess of 20% (for all rhythms)4 ,5; a key component of this improved survival is the more rapid delivery of basic life support with defibrillation, whether by bystanders or trained responders.
In the UK, ambulance performance targets require a response to 75% of cardiac arrest calls within 8 min, but with mortality increasing 10% for every minute's delay,3 only a minority of patients are potentially salvageable by the time ambulance crew arrive on scene. The first three of the four links in the Chain of Survival (early recognition and call for help, early cardiopulmonary resuscitation (CPR) and early defibrillation)2 all involve first aid that can be given by bystanders prior to ambulance arrival. Improving bystander resuscitation rates is recognised in the recent Cardiovascular Disease Outcomes Strategy as a priority area for improved care.1
The addition of public access defibrillation (PAD) to bystander CPR has been shown to double overall survival,6 with survival for those with shockable rhythms as high as 53%.7 PAD has been shown to be safe and effective, when used by members of the public even with minimal or no first aid training,8 and national PAD programmes have aimed to make public access defibrillators available in areas of high footfall such as shopping centres and transport hubs where they are likely to see service.
There are three requirements for PAD programmes to be successful: first, that there are sufficient devices placed in the community; second, that the location of the public access defibrillator is known or easily identified in the case of an emergency; and third, that the public have sufficient knowledge and confidence to use the device. All three requirements must be met for the delivery of effective bystander defibrillation. National schemes to date have generally focused on the first of these requirements, and the introduction of public access defibrillators has now been underway for more than a decade9 with significant, although unknown, numbers of public access defibrillators available across the UK. The optimal public access defibrillator density is unknown but has often been considered adequate to meet the needs to the community. However, recent studies have shown that despite significant government and community investment, defibrillators are only deployed in 0.3210–1.7%9 of OOH cardiac arrests. Whether this is a reflection of a physical lack of devices or related to identifying the location of the nearest automatic external defibrillator (AED) or lack of public confidence and knowledge to use the device is unknown. It is important to understand the reasons for these disappointingly low deployment rates in order to guide future health strategy and to improve the effectiveness of PAD to strengthen the chain of survival.
We therefore undertook a survey of 1000 members of the public, specifically to ascertain both whether they were able to identify the location of their nearest public access defibrillator and to investigate public knowledge and confidence in PAD.
Methods
Study population
In the 2011 Census, the resident population of Southampton was 236 900. The city's population had a higher percentage of students aged 15–24 years (20%) compared with the national average of 13% and the median age group was 20–24 years. In 2011, 77.7% of residents recorded their ethnicity as white British, with European, Indian and Chinese populations comprising a significant proportion of the remaining population.11
The study was undertaken outside WestQuay, a busy Southampton shopping centre between 09:00 and 17:00 on both weekdays and weekends. WestQuay has an area of 800 000 square feet (70 000 m2) of retail space, containing 150 shops. It is visited by approximately 60 000 people on an average day, but as many as 90 000 at peak times.
Study design
Members of the public were randomly approached by researchers (one of five medical students) and invited to take part in a short questionnaire (see online supplementary appendix 1). The study aimed to recruit a convenience sample of 1000 members of the public of all ages. We did not set a lower age limit and also questioned children if they volunteered to participate. Participants were only excluded if they had insufficient English or competency to participate and were excluded at the time of recruitment. In order to minimise bias, all individuals in the shopping complex were considered potential rescuers and formed the target population. The interviewers approached the nearest member of the public and aimed to be non-selective in their choice. We did not audit this selection process itself, but were assured that this protocol was adhered to. Interviewers wore a tee shirt with the South Central Ambulance Service logo to distinguish themselves from other individuals or organisations that the public may have been reluctant to engage with. Responses were based on individual opinion and were not collaborative. After the interview was completed or declined, the next individual nearest to the interviewer was approached.
Those agreeing to participate were presented with a semistructured open quantitative question set to identify public knowledge relating to PAD. The questionnaire (see online supplementary appendix 1) contained sections regarding first aid training, basic life support and defibrillator knowledge. The final question presented a scenario involving someone who had collapsed and was unresponsive. Participants were asked unprompted to describe step-by-step what they would do in order to evaluate their knowledge and abilities in a cardiac arrest scenario. The questionnaire was similar to a survey used to investigate public knowledge of first aid for OOH cardiac emergencies in Melbourne.12 No demographic data other than age group was collected. Having completed the survey, participants were offered leaflets directing them to current bystander resuscitation guidelines and a proportion (approximately 50%) were also invited to attend an emergency life support course specifically designed for this study, which would teach bystander CPR and defibrillation using AEDs.
Data analysis
Each completed questionnaire was reviewed, the results extracted and collated to a database. These results were based on what had been recorded on the forms in writing by the researcher, the details of which were aimed to provide sufficient clarity to address the question that had been asked. Results were analysed with SPSS (V.17.0; SPSS, Chicago, Illinois, USA) using descriptive statistical analysis. Continuous data (participant age) are presented as mean (SD). Proportions are reported as percentage.
STROBE statement
We have followed the STROBE recommendations (strengthening the reporting of observational studies in epidemiology (STROBE) statement: guidelines for reporting observational studies) and checklist where appropriate.13
Results
Demographics and first aid training
A total of 1004 responses were obtained between April and June 2014 from approximately 5000 people who were approached by our researchers. The questionnaire was completed in full by 1004 (100%) of respondents.
Overall age range was 9–90 years, and the median age group was 20–39 years (<20, 20–39, 40–59, >60 years age).
Of all respondents, 61.1% (613/1004) had been first aid trained to a basic life support level. The distribution of first aid training obtained by this population is shown in table 1.
Location/source of training for those with first aid knowledge
Cardiac arrest knowledge
In total, 79% (793/1004) of people reported that they would know what to do in a cardiac arrest situation (yes/no). Details of the actions that individuals would take were recorded as free text and tabulated below. No prompts were given. Results are shown in table 2 and are subdivided according to first aid training.
Self-reported actions for cardiac arrest in first aiders versus non-first aiders
Defibrillator knowledge
In total, 69.3% (696/1004) of people claimed to know what a defibrillator was and 26.1% (262/1004) reported knowing how to use one. Specific actions offered by those who stated they knew how to use a defibrillator, as well as first aider versus non-first aider comparisons, are shown in table 3.
Self-reported actions for AED use in first aiders versus non-first aiders
Only 5.1% (51/1004; first aid trained 7.0% (43/613) vs non-first aid trained 2.0% (8/391)) of people knew where or how to find their nearest public access defibrillator. Only 3.3% (33/1004; first aid trained 3.2% (32/1004) vs non-first aid trained 0.1% (1/1004)) of people would attempt to locate a defibrillator in a cardiac arrest situation, and even fewer (2.1% (21/1004); first aid trained 2.0% (20/1004) vs non-first aid trained; 0.1% (1/1004)) would actually retrieve and use the device.
First aid course
Approximately 50% of the 1004 people who had completed the survey were invited to attend a local first aid course. Numbers were limited to 500 because of the capacity of the researchers to deliver the teaching if all those invited subsequently attended. The 2 h resuscitation course was scheduled to be run on two separate weekends at the local hospital where free car parking and refreshments were also to have been provided. Multiple methods to book a course were offered (email, phone, postal). Only two individuals replied positively to the RSVP, neither of whom turned upon the day.
Knowledge by age group
Knowledge according to age group is presented with regard to cardiac arrest knowledge (table 4) and AED knowledge (table 5). We have not attempted to analyse any statistical difference between age groups as the study was not powered to enable us to draw any conclusions from this data.
Cardiac arrest knowledge by age group
AED knowledge by age group
Other
Although the majority of respondents reported that they had been first aid trained, it was apparent that most training was not up to date with current recommendations in bystander CPR. There was global confusion among the public regarding recent changes to guidelines such as hands-only CPR versus CPR with rescue breaths, and compression rates and compression to breath ratios. Our data shows that first aid training increases only theoretical knowledge of basic life support and defibrillation, but does little for confidence in a cardiac arrest scenario.
Discussion
We have investigated the reasons why rates of PAD are so poor, even in areas where public access defibrillators are available. We have found that when faced with someone who had collapsed and was unresponsive, only 2.1% of the public would attempt to find and use a public access defibrillator prior to the arrival of a trained responder. This is comparable with a recent clinical study in the same geographic region that documented PAD use in only 1.7% of actual OOH cardiac arrests.9 Although when prompted more individuals claim to know the function and purpose of using a defibrillator,14 we believe that an unprompted question is a better indicator of an individual's likely action in the event of an emergency. It is surprising that although one quarter of those questioned who claimed to know how to use a defibrillator, and therefore presumably knew why they were using it, so few would actually translate this into practical action. We also observed that only 5% of those questioned knew how to locate their nearest PAD, indicating that a major rate-limiting step in successful PAD was the ability to locate a device. There are a number of methods to locate a public access defibrillator, including personal local knowledge, assistance from security guards/staff in public areas, smart phone apps (eg, ‘AED Locator’) and dialling ‘999’ where some ambulance Trusts have rapid access to PAD databases and can give instructions as to the whereabouts of the nearest device. Subjectively, the UK does lag behind many other European countries in ensuring that public access defibrillators are clearly marked and highly visible. For example, in the shopping centre (WestQuay) where this study was conducted, there are two public access defibrillators, neither of which are marked and their location only appears known to security staff and some shop employees. Those without first aid training were unlikely to attempt to retrieve and use a public access defibrillator, and it is clear that although public access defibrillators are designed to be used safely by those with little or no training, previous first aid training is a prerequisite for successful use.
A study from the Netherlands also identified that only a minority of individuals had sufficient knowledge and willingness to operate an AED, with approximately half of those questioned having no knowledge of an AED and being unwilling to use one.15 Only 4% of individuals knew that an AED was required for a collapsed patient, knew how to locate one and stated that they would use it; a figure comparable to this study. The reasons for this are multifactorial, but include a lack of bystander willingness to use an AED in an emergency situation, lack of knowledge of the public access defibrillator location, misguided concerns over legal liabilities and poor levels of community knowledge about PAD.15 This is evident despite campaigns aimed at improving public awareness.16 There clearly remains a significant barrier with public perception and education regarding the use of public access defibrillators.
It would therefore appear that although there are growing numbers of public access defibrillators being placed in the community greater usage will not be achieved until the location of devices is more readily identified and, more importantly, the public have greater knowledge and confidence in their use. PAD schemes should ensure that their devices are clearly and prominently marked and that where possible those in the local community are trained to use them. Simply increasing the visibility of public access defibrillators should improve public awareness and therefore increase general knowledge about the devices. Ambulance trusts must work with their local communities to ensure that all public access defibrillators are entered onto a central database, accessible by all, including the public, through devices such as mobile phone apps. A single unified app for the entire UK providing this public access defibrillator information is urgently needed for public use. Education is more difficult to solve. We were disappointed that no one attended the short first aid/PAD course that was offered to them as part of this study. Education is costly and time-consuming, and public education campaigns are of limited effectiveness. The most logical and cost-effective place to undertake education is therefore a short but compulsory first aid course delivered to all school children; a strategy that would eventually see all members of the public trained as potential bystanders to deliver basic life support and PAD.
Limitations of this study relate to it being conducted at one shopping centre in one geographical locality, although we hope the sample size and the fact that a large proportion of respondents are from outside the immediate geographical area has ameliorated this to some extent. If some of the population do not use West Quay shopping centre, this may also introduce bias. Limitations also relate to this being a non-randomised study; however with a large sample size, we hope to have minimised any selection bias. We can only presume that participants who stated that they would use PAD would actually do so in a real situation, and vice versa. The data gathered excluded individuals who did not speak English or whose lack of first aid confidence was reflected in an unwillingness to participate in the survey. This may have had the effect of enhancing the results showing the knowledge and ability to use a public access defibrillator.
We conclude that although the physical presence of defibrillator is clearly necessary for successful PAD many installed devices are unlikely to be used when needed, both because of limited public first aid knowledge and the inability to locate the nearest device. The recent Department of Health's ‘Cardiovascular Disease Outcomes Strategy'1 must focus on improving public CPR and PAD knowledge (preferably by education of school children), together with ensuring that public access defibrillators are clearly marked and easily located. This is currently a greater priority than the purchase and installation of more public access defibrillators.
Key messages
What is already known on this subject?
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Public access defibrillation (PAD) prior to ambulance arrival is a key determinant of survival from the 30 000 annual out-of-hospital (OOH) cardiac arrests. Implementation of PAD has been underway in the UK since the late 1990s, and community defibrillators are now available in many areas. Despite this, PAD is only deployed successfully in 1.7% of OOH cardiac arrests.
What might this study add?
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Many public access defibrillators are unlikely to be used when needed, both because of limited public first aid knowledge and the inability to locate the nearest device. The recent Department of Health's ‘Cardiovascular Disease Outcomes Strategy’ must focus on improving public cardiopulmonary resuscitation and PAD knowledge (preferably by education of school children), together with ensuring that public access defibrillators are clearly marked and easily located. This is currently a greater priority than the purchase and installation of more public access defibrillators.
How might this impact on clinical practice?
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The poor survival rates from OOH cardiac arrest are in part related to a lack of bystander resuscitation and underuse of public access defibrillators. Increasing the rate of PAD is likely to contribute significantly to improved outcomes, but in order to achieve this, the reasons for current underuse need to be identified and addressed.
Acknowledgments
We thank the public relations team of South Central Ambulance Service for support with the survey and members of the public for their time contributing to this study.
References
Supplementary materials
Supplementary Data
This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.
Files in this Data Supplement:
- Data supplement 1 - Online supplement
Footnotes
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Contributors CDD, GAH and BB conceived and planned the study. BB, SC, PL and RA conducted the public interviews. BB collated the data and CDD wrote the first draft of the manuscript. All authors reviewed and contributed to the final manuscript. CDD is guarantor.
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Competing interests All authors have completed the Unified Competing Interests form at http://www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare the following interests: CDD—research grants from the Resuscitation Council (UK) and NIHR; Travel funding from European Resuscitation Council; Divisional Medical Director, South Central Ambulance Service; Immediate past Co-Chair, Advanced Life Support, ILCOR; Executive Committee, Resuscitation Council (UK); Director, Prometheus Medical.
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Ethics approval The Southampton National Research Ethics Service has previously confirmed that studies meeting audit criteria are not eligible for ethics review and do not require ethics approval.
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Provenance and peer review Not commissioned; externally peer reviewed.
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Data sharing statement All available data is contained within the manuscript.