The annual incidence of out-of-hospital cardiac arrest (OHCA) in England is approximately 55 per 100000 people (Resuscitation Council (UK) (RCUK), 2021). Recently published data have shown a decrease in survival-to-discharge rates, with fewer than 7.8% of OHCA patients surviving beyond 30 days in 2022 compared to 8.5% in 2021 (Warwick Clinical Trials Unit, 2022; 2023).
The chain of survival has four factors that maximise survival chances in an OHCA including early cardiopulmonary resuscitation (CPR) and early defibrillation (Nolan et al, 2006). Across the UK, bystander cardiopulmonary resuscitation (BCPR) is attempted in 70% of OHCAs and survival can be two to four times more likely with this (Perkins et al, 2016). Additionally, defibrillation within the first 5 minutes of collapse can produce survival rates as high as 70%; however, in 2021, public access defibrillators were deployed in fewer than 6% of OHCAs although this improved to 8.5% in 2022. (Perkins et al, 2016; Warwick Clinical Trials Unit, 2022; 2023).
Access to equitable healthcare is a normal expectation of a UK citizen because of the government-funded NHS. Nonetheless, higher levels of deprivation have been found to impact chances of receiving BCPR and having access to an automated external defibrillator (AED) for an OHCA, decreasing the chances of a positive outcome (Munot et al, 2022; Wang et al, 2022).
This rapid evidence review aims to critically evaluate current research within the UK and conclude whether a patient's level of socioeconomic deprivation impacts their chances of receiving BCPR and early defibrillation in an OHCA within the UK and to discuss implications for clinical practice and future research. The index of multiple deprivation ranks every lower-layer super output area (LSOA) (approximately four or five output areas (OAs) with around 400–1200 households and 1000–3000 residents) from 1 (most deprived area) to 32844 (least deprived area). Deprivation deciles are published by dividing the LSOA into 10 equal groups from the most deprived 10% to the least deprived 10%. (Department for Communities and Local Government, 2015).
Methods
Review design
This rapid evidence review was informed by Cochrane guidance and is a form of synthesis that accelerates the process of traditional systematic review; it is driven by timely evidence on urgent and emergent health issues (Garritty et al, 2020). While most of the Cochrane guidance was followed, the exception was the solo author nature of the screening, data extraction and risk of bias assessment.
Search strategy
During scoping searches, it was identified that the research topic was well researched and international literature was vast. This made an international review unmanageable given the time and resource constraints of an independently conducted review, so results were limited to those of a UK sample.
Table 1 shows the full search terms and results. All relevant papers found during scoping searches were also identified in the final search.
| Database | Searches | Results |
|---|---|---|
| CINAHL | (out of hospital cardiac arrest or ohca or prehospital cardiac arrest or pre hospital heart arrest) AND (socioeconomic status or poverty or low income or social background or socioeconomic disadvantaged) OR (aed or automated external defibrillator or defibrillator) AND (united kingdom or uk or britain or scotland or england or wales or northern Ireland) | 446 |
| PubMed | (epidemiology) AND (OHCA) AND (deprivation) | 18 |
Inclusion and exclusion criteria
A participants, issue, outcomes and studies (PIOS) framework was used, and inclusion and exclusion criteria applied. Inclusion and exclusion criteria against PIOS are shown in Table 2.
| PIOS | Inclusion criteria | Exclusion criteria |
|---|---|---|
| Participants | Patients in the UK prehospital environment who present in cardiac arrest | Any international samples Patients with any other prehospital presentation |
| Issue | Level of socioeconomic deprivation | Studies that did not record areas of deprivation |
| Outcomes | Bystander cardiopulmonary resuscitation being attempted OR The use of automated external defibrillators OR The location of automated external defibrillators | Out-of-hospital cardiac arrest research that did not focus on rates of bystander cardiopulmonary resuscitation or the use/location of automated external defibrillators |
| Studies | <10 years old Full text available Systematic reviews, randomised controlled trials, cohort studies, cross-sectional and case-control studies | Studies >10 years old Full text not available Case series, case reports, editorials and expert opinions |
Screening, data extraction and critical appraisal
All papers identified from the final search had their titles and abstracts screened against the inclusion and exclusion criteria, which significantly reduced the volume of data to produce a manageable number of studies. The studies that met the inclusion criteria were analysed in detail and again matched against the criteria to create a final pool of studies.
Data extraction of the selected papers was streamlined into a table to make the process manageable for the solo author. The Cochrane rapid review guidance was followed to describe the sample, interventions and outcomes (Garritty et al, 2020). The studies were tabulated by the following categories: study type and length; sample; outcome measure; and results.
Once these processes had been carried out, the studies were critically appraised using the Joanna Briggs Institute (JBI) checklist for analytical cross-sectional studies (Moola et al, 2024).
Synthesis technique
A narrative synthesis was adopted for this review, taking a textual approach to the process of discussing study findings (Popay et al, 2006). A meta-analysis was considered to enhance the precision of findings and identify major implications in healthcare (Deeks et al, 2024) however, a narrative synthesis was selected because data in the UK were limited. This included:
Results
Study selection and critical appraisal
After duplicates were removed and titles and abstracts were screened, 18 articles were assessed for eligibility and five observational studies were selected for final review. Figure 1 shows the PRISMA flow diagram for study selection (Page et al, 2021).
Critical appraisal results using the JBI checklist for analytical cross-sectional studies (Moola et al, 2024) were collated into one table with a colourcoded answer format of yes, no, not applicable and unclear (Table 3).
Regardless of the bias score, all five studies were included in the review because of the limited nature of relevant research within the UK. Four studies were deemed as at low risk or bias while one was scored as a high-risk bias as it failed to identify and state strategies to deal with confounding variables; this increases bias as the true association between deprivation and study outcomes may be overestimated (Skelly et al, 2012).
Summary of included studies
An overview of the five included studies is given in Table 4. Studies reported on the likelihood of BCPR (n=2), AED distribution (n=2) and survival determinants of traumatic and medical OHCA (n=1). Three studies were national, and two concerned areas covered by individual ambulance trusts.
| Article | Study type and length | Outcome measure | Sample | Results |
|---|---|---|---|---|
| Moncur et al (2016) | Retrospective study over 1 January–31 December 2011 within the North East Ambulance Service | To assess whether there is a correlation between socioeconomic status of OHCA location and the likelihood of receiving BCPR | 3179 cardiac arrests with data obtained via the internal Northeast Cardiac Arrest Network Registry. OHCA. They had to be non-traumatic in aetiology and resuscitation must have been started to be included | 3179 of the 3862 OHCAs within the area were included; exclusion was because of incomplete data or for being witnessed by EMS. There were more men than women in every quintile of deprivation and the median age of th demographics rose between quintiles 1 and 5. 623 out of the 3179 OHCAs (19.6%) received BCPR. BCPR rates rose from 14.5% to 23.2% betwee the most deprived quintile to the least deprived |
| Barnard et al (2019) | Observational retrospective study over 1 January 2015–31 July 2017 within the East of England Ambulance Service area | To understand the determinants of survival in OHCA, including medical and trauma aetiologies. |
9109 OHCAs within an area of 20 000km2 that had a population of 6 395 000 as of June 2016. This study included traumatic and non-traumatic cardiac arrest cohorts. |
9109 OHCAs during the study period, of which 8806 (96.7%) were non-traumatic and 304 (3.3%) were traumatic. |
| Brown et al (2019) | Observational retrospective study across England of OHCA over 1 April 2013–31 December 2015 | To identify the neighbourhood characteristics of areas with high OHCA but low BCPR rates | A total of 76 456 OHCAs were recorded in the study period, with 67 219 (88%) eligible for inclusion. |
BCPR increased from 50.2% in 2013 to 61.5% in 2015 (P<0.05) |
| Brown et al (2022) | Observational retrospective study of AEDs registered with English ambulance trusts in 2019 and neighbourhood characteristics for every postcode district based on the 2011 census | To research disparities in AED placement across England | Data from 32 234 registered AEDs collated for 10 of the 11 English ambulance services. The coordinates of each AED were allocated to the relevant LSOA, and Index of Multiple Deprivation score obtained for each of these areas | LSOA within Index of Multiple Deprivation decile 1 and 2 had the lowest coverage of registered AEDs, with only 27.4% of them containing a device. |
| Leung et al (2021) | Observational retrospective study over 1 January 2011–30 September 2017 including all OHCAs (treated and untreated) where the Scottish Ambulance Service was dispatched. |
Examining the distribution of AEDs across Scotland to explore whether the alignment between AEDs and OHCAs across levels of deprivation could be optimised | 49 752 OHCAs were recorded, of which 320 were excluded because of duplication, no location or occurring outside Scotland. |
Highest amount of OHCA in quintile 1 (the most deprived 20% under the Scottish Index of Multiple Deprivation) at 30.7%. |
AED: auto arrest. Ou LSOA: low area (OA): lowest level of layer super output area – t bystander cardiopulmon census area with four or five OAs with around 400–1200 households medical services; OHCA: out-of-hospital cardiac
Impact of deprivation on bystander cardiopulmonary resuscitation rates
Moncur et al (2016) studied cardiac arrests (n=3179) in the north-east of England in 2011. Of these, 20% (n=623) of patients received BCPR across all five quintile areas (quintile 1: highest deprivation; quintile 5: lowest deprivation). Of the quintile 1 patients, 14.6% (n=97) patients received BCPR. Rates positively increased as levels of deprivation decreased, with the highest percentage of the sample population receiving BCPR being 23.3% in quintile 4 (n=123) and quintile 5 areas (n=122) (Table 5).
| Index of Multiple Deprivation quintiles | Number of OHCA | Number of OHCAs with BCPR received |
|---|---|---|
| Moncur et al (2016) | ||
| 1 (most deprived) | 666 | 97 (14.6%) |
| 2 | 795 | 143 (18.0%) |
| 3 | 667 | 138 (20.7%) |
| 4 | 528 | 123 (23.3%) |
| 5 (least deprived) | 523 | 122 (23.3%) |
| Brown et al (2019) | ||
| 1 (most deprived) | 16 774 | 3723 (22.2%) |
| 2 | 14 577 | 3501 (24.0%) |
| 3 | 13 365 | 3476 (26.0%) |
| 4 | 11 945 | 3149 (26.4%) |
| 5 (least deprived) | 10 558 | 2751 (26.1) |
BCPR: bystander cardiopulmonary resuscitation; OHCA: out-of-hospital cardiac arrest
Brown et al (2019) analysed 67219 OHCA cases and categorised areas by postcode districts (n=2050) for analysis. Bystander-witnessed OHCAs (n=28514) had a BCPR mean of 56.8% (n=16600) across all quintiles. Within quintile 1 areas, 22.2% (n=3723) of bystander-witnessed OHCA received BCPR. As with Moncur et al (2016), BCPR rates increased as the index of multiple deprivation decreased, with 26.1% (n=2751) of OHCAs in quintile 5 areas receiving BCPR.
Barnard et al (2019) conducted an analysis of traumatic and non-traumatic OHCAs in the east of England. There were 9109 OHCAs within the study period, and BCPR occurred in 54.6% of non-traumatic cardiac arrests (n=4716) and in 52.2% of traumatic cardiac arrests (n=156). A univariable analysis found a positive association between increasing BCPR and decreasing rates of deprivation (P=0.002). The study does not provide any data breakdown on BCPR rates within each quintile, which is a weakness of this study. However, because the national data pool is small, the study was still included in the review.
Out-of-hospital cardiac arrest rates and deprivation
Leung et al (2021) found that 30.7% (n=15279) of all OHCAs within the study period occurred in quintile 1 areas. Incidence fell as deprivation decreased, with quintile 5 areas having a rate of 11.22% (n=5581) (Table 6).
| Quintile 1 (most deprived) | Quintile 2 | Quintile 3 | Quintile 4 | Quintile 5 (least deprived) | |
|---|---|---|---|---|---|
| Moncur et al (2016) | 666 (20.9%) | 795 (25.0%) | 667 (21%) | 528 (16.6%) | 523 (16.5%) |
| Brown et al (2019) | 16 774 (25.0%) | 14 577 (21.7%) | 13 365 (19.9%) | 11 945 (17.8%) | 10 558 (15.7%) |
| Leung et al (2021) | 15 279 (30.74%) | 11 771 (23.7%) | 9607 (19.31%) | 7454 (15%) | 5581 (11.22%) |
Brown et al (2019) reported that 25.0% of OHCA were in quintile 1 areas (n=16774). OHCA incidence fell in line with reducing deprivation, with a 15.7% incidence in quintile 5 (n=10558) reflecting the findings by Leung et al (2021) (Table 6).
Moncur et al's (2016) findings, however, did not find a linear correlation between decreasing deprivation and OHCA rates. Quintile 2 areas had the highest OHCA incidence rate of 25.00% (n=795), with quintile 1 in the middle at 20.90% (n=666).
Nonetheless, all three studies found quintile 5 areas (least deprived) to have the lowest OHCA rate (Moncur et al, 2016; Brown et al, 2019; Leung et al, 2021), demonstrating that multiple studies have found OHCA incidence in the UK is the lowest in the least deprived areas.
Defibrillator presence and deprivation
Of the 1532 AEDs reported in Leung et al's (2021) study, 10.0% (n=153) were located in quintile 1 areas despite these places having the highest prevalence of OHCA. Quintile 3 areas had the highest number of AEDs (n=472), indicating a discrepancy in rates of OHCA and AED access as deprivation increases. This quintile went against the trend of an increase in AED access as deprivation decreases. An OHCA was deemed to be covered by an AED if it was within 100 metres walking distance; within quintile 1 areas, 0.4% of OHCAs were covered by an AED.
Brown et al (2022) found quintiles 1 and 2 to have the lowest AED coverage at 27.4% (n=899). Areas deemed more affluent as they had a lower percentage of household deprivation and a greater deprivation mean had a statistical significance (P<0.001) of having at least one AED in that area.
Brown et al (2022) categorised data through the 2021 Index of Multiple Deprivation using deciles rather than quintiles and did not include a breakdown of exact AED figures within each decile, while Leung et al (2021) used the Scottish Index of Multiple Deprivation quintiles; while both worked off the same principle of quintile 1 being the most deprived 10%, direct data comparisons are difficult given the different presentation of findings.
Overall, AED research within the UK is limited, reducing the impact of results included within this review. As the results indicate, a patient's level of socioeconomic deprivation affects their likelihood of receiving BCPR and defibrillation for an OHCA.
Both studies focusing on AED use (Brown et al, 2021; Leung et al, 2021) concluded that AED placement should be guided to match OHCA incidences and high-risk neighbourhood characteristics.
BCPR studies suggested that low-BCPR and high-OHCA areas should be specifically targeted for CPR and AED use training (Moncur et al, 2016; Barnard et al, 2019; Brown et al, 2019).
Discussion
This review has highlighted that, as levels of deprivation increase, rates of BCPR decrease, as does the availability of AEDs; yet the incidence of OHCA rises. However, this review only included studies from the UK. In order to assess the generalisability of these findings a comparison with international literature is key.
International bystander cardiopulmonary resuscitation
In Korea, a 10-year observational study found rates of BCPR rose during the decade but the degree of improvement was greater in communities with higher socioeconomic status; BCPR rates increased from 1.6% to 15.5% in the most deprived communities while the least deprived communities saw an improvement of 1.6% to 34.6% despite having a lower OHCA rate (Lee et al, 2018).
In Northern Carolina (USA), communities that had a high OHCA incidence and low BCPR rates had a poverty median of 18.9% compared to one of 6.3% in areas with low OHCA rates and high BCPR incidence (Fosbøl et al, 2014). A national review from 2005 to 2009 found BCPR was provided in 28.6% (n=4068) of OHCAs and that patients in low-income black neighbourhoods were approximately 50% less likely to receive BCPR than high-income neighbourhoods of any race (Sasson et al, 2012).
An international systematic review of OHCA survival to discharge predictors, which included 79 studies from 1984 to 2008, found 3.9%–16.1% of OHCAs with BCPR survived to discharge; however, only 32% of all witnessed OHCAs received BCPR (Sasson et al, 2010). This review did not monitor deprivation; the UK research discussed in the present study found patients from more deprived areas are less likely to receive BCPR, so it can be theorised they are less likely to survive to discharge.
The EuReCa TWO study included data from 28 countries with 8% of patients surviving to discharge, with higher discharge rates among those who received bystander CPR and ventilation compared to compression-only CPR (Gräsner et al, 2020). This highlights a further need for research into how countries and organisations define CPR and into the two CPR techniques in the UK and why their outcomes differ.
International defibrillator placement
In Seoul, areas of higher socioeconomic status as per tax quintiles have a higher per-capita AED coverage. Quintile 1 areas had 4.92 devices per capita while quintile 4 districts had a 12.66 coverage. Overall, there were 40% more AEDs in quintile 4 than quintile 1 areas (Lee et al, 2017).
A New Zealand-based study categorised census area units into deprivation deciles 1–10 and found decile 10 areas, which had the most deprived 10% of the population, had double the incidents of OHCA alongside the lowest AED access; 65% of areas categorised as decile 10 (n=112) contained an AED compared to 84% coverage in decile 8 (Dicker et al, 2019).
Within New South Wales (Australia), research found that an AED was used in 3% out of 16914 OHCAs (n=456). The most advantaged quintile locations (quintile 5), had the greatest use of AEDs at 31% (n=145), compared to 13% (n=61) from quintile 1 areas (Munot et al, 2022).
Implications for public health and clinical practice in the UK
Studies in this review concluded that, within the UK, greater CPR engagement is needed to promote the skills and spread awareness of basic life support and that CPR teaching should be targeted at areas of greater deprivation and higher rates of OHCA (Moncur et al, 2016; Barnard et al, 2019; Brown et al, 2019; 2022). CPR teaching is typically based within workplaces or through charity organisations, which is unsuitable for communities with higher OHCA rates as people in deprived areas typically have lower employment rates and work in lower skilled roles with fewer holding managerial positions, suggesting that they may not be provided with workplace education.
Significantly, Brown et al (2019) identified high-risk areas within the UK such as the north-east, Yorkshire, Milton Keynes, Cornwall, Somerset, Derbyshire, Wiltshire, Kent and Leicester. These areas were found to have an above average OHCA occurrence with a below average BCPR rate (Brown et al, 2022). This is pertinent for targeting future education and for ambulance service trusts to become aware of high-risk locations, which can influence resourcing, public campaigns and multidisciplinary work to improve health and cardiac arrest knowledge in these areas.
AED placement nationally should be reformed to take a mathematical approach targeting areas with high OHCA and population density. Additionally, targeted AED teaching, such as CPR training, should be implemented to ensure mathematical placement is supported by improved public knowledge (Brown et al, 2022; Leung et al, 2021).
East Midlands Ambulance Service (EMAS) has the greatest defibrillator coverage with 63.7% of lower layer super output areas (census areas with about 400–1200 households and 1000–3,000 residents) containing an AED compared to the lowest being North East Ambulance Service (NEAS) with a 19.5% rate (Brown et al, 2022). EMAS has more AEDs (n=5591) than NEAS (n=535). Correlating these findings to the high-risk areas found by Brown et al (2019) shows that the north east is a key area with low BCPR rates and high OHCA incidence. This area should therefore be targeted by public health professionals, NHS England and NEAS to explore how OHCA can be managed more effectively through AED location, public knowledge and exploring the in-depth health within the area to identify any health conditions or campaigns that need targeting to potentially reduce the high OHCA incidence.
Finally, the UK national JRCALC [Joint Royal Colleges Ambulance Liaison Committee] guidelines (Association of Ambulance Chief Executives (AACE), 2022) lack any acknowledgement of health inequalities and disparities in cardiac arrest incidences. Men in areas of high deprivation live 9.7 years less than their counterparts in the least deprived locations; similarly, women in the most deprived areas have a life expectancy that is 7.9 years shorter than those in the least impoverished areas (Office for National Statistics (ONS), 2022). Furthermore, healthy life expectancy at birth in the most deprived areas is 52.3 years compared with 70.5 years in the least deprived areas. Female healthy life expectancy is 51.9 years in the most deprived areas compared to 70.7 years in the least deprived.
These are huge disparities nationally which, undoubtedly, put communities with high deprivation levels at an increased risk of medical OHCA (ONS, 2022). In the UK, 80% of cardiac arrests are of cardiovascular aetiology (RCUK, 2021), with cardiovascular disease being significantly associated with higher levels of deprivation, with 40% of amenable cardiovascular deaths occurring with deciles 1–3 in England (UK Health Security Agency, 2021). Arguably, guidelines and education should inform ambulance service clinicians of inequalities to help with their holistic decision-making and care planning.
Strengths and limitations
A strength of this review lies in its focus on geographic location in the UK, which makes the findings more relevant locally. This, however, is also a limitation in that the results may not be generalisable beyond the UK.
This review cannot determine causality as it included only observational studies. Nonetheless, it may identify associations which would be useful to explore further.
Study screening, data extraction and critical appraisal were undertaken by one reviewer. Therefore, some studies may have been missed and the critical appraisal may have been subject to bias. Critical appraisal checklists were used to strengthen the rigour of the quality assessment.
Finally, as no additional authors were involved during the synthesis, the possibility of researcher bias cannot be ignored; the lead reviewer has a professional interest in health inequalities. The authors aimed to offset this bias by including only quantitative studies, thereby making the review more objective.
Recommendations for future research
This review has found an association between deprivation and low rates of BCPR and AED access. Although one study showed a high risk of bias during critical appraisal, the present study's recommendations are based on the collective findings from all five papers which, overall, have a low risk of bias as the remaining studies were deemed low risk and the narrative synthesis found a correlation in findings across all papers.
Two key suggestions have been made for future research:
Conclusion
This rapid evidence review has found a significant disparity regarding receiving bystander cardiopulmonary resuscitation and access to automated external defibrillation in OHCA because of socioeconomic deprivation. The government, the UK Health Security Agency and the NHS need to identify high-risk areas that can be targeted for the installation of AEDs and provide public campaigns promoting the chain of survival and cardiac arrest knowledge.
The reasons behind these disparities are multi-factorial. People in more deprived communities live for a shorter time in a healthy condition and experience complex medical presentations that put them at an increased risk of medical cardiac arrests.
While specific communities have been identified as being at a high risk for low BCPR and having a high OHCA occurrence, research is needed nationally to match the quality of international research to understand why deprived patients are less likely to receive bystander CPR and community defibrillation and to explore the political, social and medical impacts of deprivation on health to improve life expectancy and OHCA management.