Background
Acute chest pain is responsible for approximately 700,000 patient attendances per year at emergency departments in England and Wales and 20–30% of emergency medical admissions [
1]. The Chest Pain Unit (CPU) has been developed to improve care and reduce costs for patients with acute chest pain. A single centre study [
2] has shown that CPUs care can reduce admissions, reattendances and outpatient follow-up, and improve quality of life for selected low-risk patients who are suitable for CPU care.
The ESCAPE (Effectiveness and Safety of Chest pain Assessment to Prevent Emergency admissions) multicentre trial was undertaken to determine whether CPU could reduce admissions, improve outcomes and be cost effective across a variety of NHS hospitals. The main analysis from the ESCAPE multicentre trial [
3] showed that the introduction of CPU care across a range of hospitals: 1) Did not alter the proportion of patients admitted, 2) Was associated with increased reattendances and subsequent admissions and 3) May have been associated with increased numbers of patients attending with chest pain. It concluded that establishing CPU care throughout the NHS could not be justified on the basis of any expectation of reducing emergency admissions.
Even if CPU care does not reduce hospital admissions it may still be cost-effective, compared to routine care, if it improves patient outcomes or reduces health service costs in other ways, such as by reducing length of hospital stay. We therefore planned to undertake an economic evaluation alongside the ESCAPE multicentre trial [
3], using data from the trial and from external sources in a decision-analytic model (the rationale for using this type of model is explained in a later section). Our specific objective was to estimate the cost-effectiveness of CPU, compared to routine care, in terms of the incremental cost per quality adjusted life year (QALY) gained. This outcome measure allows us to combine length of life and quality of life into a single summary measure and thus allows a multidimensional comparison of CPU care with routine care.
Discussion
We found that on average CPU care would result in a cost saving compared to routine care, although this was not a statistically significant result. The probability that CPU care is cost effective is approximately 70% at a willingness to pay threshold of £20,000 per QALY. This finding, however, is subject to uncertainty and it is necessary to bear in mind the substantial investment that would be needed to provide CPU care throughout the NHS. On the basis of this analysis we cannot justify widespread implementation of CPU care throughout the NHS.
Most previous cost-effectiveness analyses of CPU care originate from the United States (Roberts, Farkouh, Gomez [
11‐
13]). These studies were based on randomised trials comparing CPU care to inpatient care that primarily compared resource use and did not evaluate patient-centred outcomes. They showed that CPU care was cheaper than routine care, but it is not clear whether this finding can be extrapolated outside the United States. It is also only relevant if CPU care replaces inpatient care. Although practice in the UK has changed recently, with increasing use of percutaneous coronary intervention, the findings of the ESCAPE trial [
14] suggest that many patients with chest pain still do not receive inpatient care.
One previous cost-effectiveness analysis in the UK, based on a single-centre randomised trial [
2], showed a significant improvement in QALYs and a non-significant reduction in costs among selected low risk patients who were deemed suitable for CPU care. These findings were not fully reproduced in the ESCAPE trial. Both the QALY gain and cost reduction associated with CPU care were smaller than in the single-centre trial and were non-significant. This is presumably because the ESCAPE multicentre trial evaluated the effect of CPU care across all patients with chest pain, rather than selected low-risk patients. The effect of CPU care may therefore have been lost amongst the overall population with chest pain or balanced by negative effects from implementing CPU care upon patients who attended CPU hospitals with chest pain but did not receive CPU care.
This economic analysis has an important limitation that needs to be taken into account in interpreting the findings. The comparison of the costs and effects of CPU versus routine care is made on a per patient basis, which assumes that CPU and routine care will be applied to the same population of patients attending hospital. In other words, it assumes that the decision to implement CPU care or continue with routine care does not influence the size or characteristics of the population requiring the services. However, it has been reported elsewhere [
14] that the implementation of CPU care may be associated with increased attendances with chest pain and increased medical admissions. If introducing CPU care leads to increased attendances with chest pain then the assumptions in this analysis will not hold. Furthermore, whereas it is clear that additional attendances will incur health service costs, we do not have any evidence that they will gain benefit from their attendance.
Thus evidence, which cannot be incorporated in the economic model, leads us to believe that introducing CPU care may increase health service costs without any corresponding evidence that it will improve outcomes. In these circumstances it is difficult to claim that CPU is likely to be cost-effective, especially considering the substantial uncertainty surrounding the results on the economic analysis.
Another limitation is that there was considerable variation in outcomes between the individual hospitals involved in the ESCAPE trial and in the effect of introducing CPU care at individual CPU hospitals. We therefore cannot exclude the possibility that individual CPUs can markedly reduce costs and improve outcomes. Indeed, the previous single centre study [
2] showed that an active CPU can improve outcomes and possibly reduce costs among selected patients. However, we can reasonably conclude that widespread implementation of CPU care is unlikely to represent a cost-effective use of health service resources.
We recently surveyed the development of chest pain services in the UK [
15] and found that formal development of CPU care was limited and mostly restricted to within trials, although there was substantial informal and ad hoc development of acute chest pain services. The findings of our analysis and the ESCAPE multi-centre trial suggest that this progress is probably appropriate and that investment in formal development of CPU care throughout the UK would be misplaced.
Acknowledgements
Project management group: Jane Arnold, research fellow, University of Sheffield (clinical manager); Simon Capewell, professor of clinical epidemiology, University of Liverpool (northwest lead); Liz Cross, research associate, University of Sheffield (research manager); Steve Goodacre, professor of emergency medicine, University of Sheffield (principal investigator); Maxine Johnson, research associate, University of Sheffield (qualitative researcher); Cath Lewis, research associate, University of Liverpool (northwest coordinator); Francis Morris, consultant in emergency medicine, Northern General Hospital, Sheffield (chest pain unit adviser); Jon Nicholl, director MCRU policy research programme, University of Sheffield (statistician); Yemi Oluboyede, research associate, University of Sheffield (health economist); Susan Read, honorary research fellow, University of Sheffield (nursing adviser); Angela Tod, principal research fellow, Centre for Health and Social Care Research, Sheffield Hallam University (qualitative adviser).
Trial Steering Committee: Phil Adams, consultant cardiologist, Newcastle upon Tyne NHS Foundation Trust (co-applicant); Tim Coats, professor of emergency medicine, University of Leicester (independent member); Nicky Cullum, professor, Centre for Evidence Based Nursing, University of York (independent chair); Alasdair Gray, consultant in emergency medicine, Edinburgh Royal Infirmary (co-applicant); Enid Hirst (lay member); Jason Kendall, consultant in emergency medicine, Frenchay Hospital, Bristol (independent member); David Newby, professor of cardiology, University of Edinburgh (co-applicant); Simon Dixon, senior lecturer, University of Sheffield (health economist).
Data Monitoring Committee: Jonathan Benger, consultant in emergency medicine, Bristol Royal Infirmary; David Gray, reader in medicine and honorary consultant physician, Epidemiology and Health Services Research Unit, Queen's Medical Centre, Nottingham; Robin Prescott, statistical adviser, Medical Statistics Unit, Public Health Sciences, University of Edinburgh.
Principal trial staff: University Hospital Aintree – John Hollingsworth (ED lead), Erwin Rodrigues (cardiology lead), Paula McCarten (cardiac specialist nurse); Whiston Hospital – David Roe (ED lead), Dave Johns (chest pain nurse); Halton General Hospital – Serge Osula (cardiology lead), Karen Randles (cardiac nurse specialist); Wythenshawe Hospital – Darren Walter (ED lead); Warrington Hospital – Steve Crowder (ED lead), Cindy Lancaster (ED nurse); West Cumberland Hospital – Charles Brett (ED lead), Guy Bickerton (ED lead); Peterborough District Hospital – Rob Russell (ED lead); Dewsbury and District Hospital – Dean Okereke (ED lead); Scunthorpe General Hospital – Ajay Chawla (ED lead), Julia Lindley (administration/systems manager), Julie Housham (chest pain nurse), Sarah McGugan (chest pain nurse); Queen's Medical Centre Nottingham – Frank Coffey (ED lead), Phil Miller (ED research coordinator); Taunton and Somerset Hospital – Cliff Mann (ED lead), Andria Haffenden (chest pain nurse), Bridget Capewell (chest pain nurse); Hairmyres Hospital – John Keaney (ED lead); City Hospital Birmingham – Nigel Langford (MAU lead); Worcestershire Royal Hospital – Rose Johnson (ED lead), David Pitcher (cardiology lead), Sue Amos (chest pain nurse), Sally Baker (chest pain nurse).
We thank Margaret Jane and Sarah Lampard for clerical assistance and the staff at the participating hospitals for their help with this study and the statistical support provided by Stephen Walters.
The ESCAPE trial was funded by the NHS Service Delivery and Organisation R&D programme. The funders played no role in developing the study design; in the collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the article for publication.
Competing interests
The authors declare that they have no competing interests.
Authors' contributions
All authors contributed to the data analysis, writing the article and approved the final draft. YO and SG are the guarantors.