- Email: [email protected]
A gatekeeper for the gatekeeper: Inappropriate referrals to stress echocardiography
Imaging and Diagnostic Testing
A gatekeeper for the gatekeeper: Inappropriate referrals to stress echocardiography Eugenio Picano, MD, PhD,a Emilio Pasanisi, MD,a Joseph Brown, BS,b and Thomas H. Marwick, MD, PhDb Brisbane, Australia; and Pisa, Italy
Background Cardiac imaging stress tests have increased nearly 3-fold in the last decade, with N10 million a year performed in the United States alone. Inappropriate selection for testing may have important consequences because small individual costs (and risks) multiplied by millions of examinations represent a significant societal burden. The aim of this study was to assess the appropriateness of selection for stress echocardiography in 2 high-volume laboratories. Methods This audit of 350 consecutive stress echocardiograms for evaluation of known or suspected coronary artery disease was performed from May to June 2006 at centers in Australia and Italy. Appropriateness was independently scored by a senior clinical cardiologist as follows: I = definitely appropriate, IIa = probably appropriate, IIb = probably inappropriate, or III = definitely inappropriate, based on current guidelines for cardiac stress testing. All referrals were accepted at one center, and referrals were prescreened by cardiology fellows working at the other. Results
Examinations were definitely appropriate in 217 (62%), probably appropriate in 35 (10%), probably inappropriate in 76 (22%), and definitely inappropriate in 22 (6%) patients. The main reasons of inappropriateness were (1) performance as first-line test (37% of inappropriate tests) and (2) test repeated too often in the absence of change in clinical status (30%). The inappropriate testing rate was higher when no screening of external referral was implemented (43% vs 13%, P b .0001).
Conclusions Inappropriate indications for stress echocardiography are common but avoidable if referrals are screened. Targeting inappropriateness opens a unique opportunity to cut health care expenditure with no reduction, and possibly improvement, in health care standards. (Am Heart J 2007;154:285290.) Noninvasive cardiac imaging with myocardial perfusion imaging,1 cardiovascular magnetic resonance,2 computed tomographic (CT) coronary angiography,3 and stress echocardiography4 may facilitate the selection of patients for invasive procedures and interventions.5,6 Although the diagnostic and prognostic information provided by these tests is itself not without cost—both financial and safety—some studies have shown that the use of noninvasive imaging in appropriately selected patients translates into cost savings because of more appropriate selection for even more expensive procedures.7,8 However, these studies have involved patients who were appropriately selected for testing; and the trade-off between costs and benefits will not be the same when studies are performed less appropriately.9,10 The problem of overuse of imaging tests is especially relevant in cardiology because cardiovascular imaging From the aDepartment of Medicine, Princess Alexandra Hospital, University of Queensland, Brisbane, Australia, and bCNR, Institute of Clinical Physiology, Pisa, Italy. Submitted March 1, 2007; accepted April 11, 2007. Reprint requests: Thomas H. Marwick, MD, PhD, Department of Medicine, Princess Alexandra Hospital, University of Queensland, Ipswich Road, Brisbane Qld 4102, Australia. E-mail: [email protected] 0002-8703/$ - see front matter D 2007, Mosby, Inc. All rights reserved doi:10.1016/j.ahj.2007.04.032
amounts for at least 50% of all imaging testing.11 In particular, imaging stress testing is rising at an impressive rate. In the United States, from 1993 to 2001, there was a nearly 3-fold increase in the use of imaging stress tests,12 reaching N9 million stress single photon emission CT (SPECT) myocardial perfusion imaging procedures in 2002.1 Although the number of stress echocardiograms is less—according to 1998 Medicare data, 1 stress echocardiogram was performed every 4 stress SPECT myocardial perfusion scans13—this also amounts to a substantial number of studies. Despite the immense benefits of this diffusion of stress imaging testing, the associated costs are very high and probably unsustainable at current levels.1,14 Guidelines established by credible societies and professional bodies form a reasonable basis for defining the appropriateness of testing. In this study, we sought to define the appropriateness of referral to stress echocardiography at expert centers in different health systems.
Methods Study design We audited 350 stress echocardiography examinations performed at the Institute of Clinical Physiology, Pisa, Italy, and the University of Queensland Cardiovascular Imaging group,
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286 Picano et al
Table I. Indications for testing at 2 centers Indication Asymptomatic Stable angina Nonspecific chest pain After ACS After revascularization Before major surgery Total
Class I
Class IIa
Class IIb
Class III
Total
12 54 54 38 15 44 217
11 6 12 1 5 0 35
18 10 33 1 11 3 76
11 1 4 0 5 1 22
52 71 103 40 36 48 350
ACS; Acute coronary syndrome.
Princess Alexandra Hospital, Brisbane, Australia—each center contributing 175 consecutive examinations. All indications were clinically driven and referred from a clinician through the outpatient clinic or inpatient wards. However, the general policy of test booking was different in the 2 contributing centers: center 1 directly accepted the referrals, whereas in center 2, requests were filtered by a cardiologist or trainee working in the laboratory.
Definition of appropriateness For all individual examinations, a senior clinical cardiologist independently reviewed clinical and imaging information relating to the request for testing, including review of the patient chart. The first step involved defining the frequency of inappropriate testing. Indications for testing were divided into 6 categories: asymptomatic, stable angina, nonspecific chest pain, postacute coronary syndrome, postrevascularization, and before major surgery. Within each category, the clinical presentation was used to define whether the clinical setting corresponded to an appropriate indication for stress echocardiography based on the latest (2003) specialty guidelines of the American College of Cardiology (ACC)/American Heart Association (AHA) for cardiac stress testing,5 as follows: I = definitely appropriate (the procedure should be performed; benefit { risk), IIa = probably appropriate (it is reasonable to perform the test; benefit J risk), IIb = probably inappropriate (procedure may be considered; benefit z risk), or III = definitely inappropriate (risk z benefit). The second step involved categorizing the causes of inappropriateness (in classes IIb and III), using groupings according to European Union Medical Imaging guidelines (2001), into one of 6 possible broad categories9: 1. Repeating investigations that have already been done (eg, at another hospital). 2. Investigation when results are unlikely to affect patient management (eg, because the anticipated bpositiveQ finding is usually irrelevant or because a positive finding is so unlikely). 3. Investigating too often (eg, before the disease could have progressed or resolved or before the results could influence treatment). 4. Doing the wrong investigation. 5. Failing to provide appropriate clinical information and questions that the imaging investigation should answer.
6. Excessive investigation. Some clinicians tend to rely on investigations more than others, and some patients have inappropriate expectations of the optimal type of examination.
Statistical analysis We expressed continuous data as mean F SD and dichotomous variables as percentages. We compared continuous data with unpaired-samples Student t test and proportions by the m2 statistics. We considered statistically significant a P value b .05.
Results Patient characteristics Starting from 1 May 2006, 350 consecutive patients (age = 62 F 7 years, 231 men) underwent stress echocardiography for the evaluation of known or suspected ischemic heart disease. The stress used was exercise (n = 187) or pharmacological (with dipyridamole or dobutamine in 38 and 125, respectively, patients unable to exercise). The clinical presentation of the 350 patients and the classes of indications broken down according to clinical status are listed in Table I. Appropriateness of testing Indications were partially or totally inappropriate in about 1 of 4 patients (Figure 1). The number of patients with positive stress echocardiograms was higher in the 252 patients with class I or IIa indication than in the 98 patients with class IIb or III indication (38.5% vs 9%, P = .0001). The major source of inappropriateness was a class IIb indication in patients with nonspecific chest pain or in those who are asymptomatic (Table I). The criteria for appropriateness are clearly a determinant of its prevalence. Nonetheless, even if the more bliberalQ scoring of the European Society of Cardiology (ESC) 2006 guidelines were adopted, the inappropriateness rate in our population remained at 14.5% (7% in center 2 and 22% in center 1). Reasons for inappropriate testing The reasons for inappropriateness in the 98 patients with class IIb or III indications are shown in Figure 2.
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Figure 1
Appropriateness rate of stress echo examinations. Overall appropriateness rate in the overall population of 350 patients recruited from the 2 centers.
The top 2 reasons of inappropriateness (classes IIb and III) were (1) 36 tests performed as first-line test (37% of all inappropriate tests) and (2) 29 tests performed in patients as a part of a regular follow-up program (after an acute event or mechanical revascularization) at 3- or 6-month interval (from the revascularization or previous stress echo) in the absence of any change in the clinical status (30% of all inappropriate tests). The inappropriateness rate was 3-fold higher in center 1 (Figure 3), accepting referrals without prescreening and filtering, which were routine parts of the policy of testing in center 2. The impact of less stringent criteria is shown in Figure 4.
Discussion The results of this audit of highly experienced stress echocardiography laboratories show that the number of costly examinations with inappropriate indication and/ or inadequate clinical utilization of test results is high. There is variability of test indication and patient selection between sites; and this seems to be based on local practice for test approval, with more inappropriate testing in the setting of open access to testing.
The risks and costs of inappropriateness Useless examinations pose an economic burden to society, restrict access to patients in need, carry acute risks without offering commensurate benefit, and do not increase (and possibly reduce) the quality of health care.14 In case of stress imaging, there is also a nonnegligible risk associated with the administration of
Picano et al 287
Figure 2
Sources of inappropriateness. Reasons of inappropriateness, as suggested by European Commission Medical Imaging guidelines, in the 98 patients (from centers 1 and 2) with class IIb or III indication to testing.
physical or pharmacological stress.15-18 By definition, risk is outweighed by benefit for appropriate, but not inappropriate, examinations, which should therefore be kept as low as possible also to minimize the litigation potential linked to development of complications during inappropriate testing.19 From the medicolegal viewpoint, according to the Euratom law, both the prescriber and the practitioner are responsible for the justification of the test exposing the patient to a potential risk. The problem of waste and inappropriateness in medical testing is neither new nor restricted to cardiovascular imaging. In the field of laboratory medicine, at least 1 of 3 examinations is deemed inappropriate.20 More than 20 years ago, a Lancet editorial complained of the bflooding of laboratory testingQ requested by clinicians who believe that ball seems to be for freeQ and often ask for bdiagnostic carpet bombingQ instead of carefully targeted, clinically driven testing.20 After 20 years, the same pattern seems to apply to cardiac stress imaging testing. However, the economic pressure has increased; and in an era of health care rationing, now the waste of resources can seriously endanger access to the benefit of sophisticated testing for those who are in real need. For a resting cardiac imaging test, the average cost (not charges) of an echocardiogram being equal to 1 (as a cost comparator), the cost of a CT is 3.1; a SPECT, 3.2; a cardiovascular magnetic resonance imaging, 5.51; a positron emission tomographic scan, 14.03; and a right and left heart catheterization, 19.95.2 For
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288 Picano et al
Figure 3
Figure 4
Interinstitutional differences based on ESC 2006 guidelines.
Interinstitutional differences based on AHA/ACC 2002/2003* guidelines. Intercenter variations in appropriateness rates on the basis of the policy of referral to testing. Appropriateness is higher for center 1, with pretesting screening of specialist cardiologist referral by a cardiology fellow.
stress cardiac imaging, compared with the treadmill exercise test equal to 1 (as a cost comparator), the cost of a stress echo is 2.1 and that of a stress SPECT scintigraphy is 5.7.5 In other words, the costs of useless examinations are immense. Not surprisingly, expenses for medical imaging are today one of the highest cost items in a health plan’s medical budget and also one of the fastest growing. Diagnostic imaging services reimbursed with Medicare’s physicians fee grew more rapidly than any other type of physician service from 1999 to 2003.21
Comparison with previous studies The relatively high rate of partially appropriate or frankly inappropriate examinations found for stress echocardiography in the present study is consistent with findings observed with a variety of imaging techniques. A recent survey of the Italian Association of Echocardiography showed that 50% of resting transthoracic echocardiograms are totally or partially inappropriate.22 The rate of inappropriateness is also considered to be about 30% for radiological testing.23 The inappropriateness rate of coronary angiography has been described to be as high as 65% in some tertiary care referral centers.24 Furthermore, in the field of stress radionuclide perfusion imaging, more costly than stress echocardiography and not without additional long-term risks due to the use of radiation. The inappropriateness rate was reported to be N20% in a high-volume nuclear medicine laboratory.25 Thus, the
appropriateness rate of stress echocardiography observed in the current study seems to be no exception to the pandemic of inappropriateness in modern imaging.9
Limitations of guidelines to define appropriate test selection The greatest proportion of inappropriate studies were due to the permissive use of stress imaging as an alternative to exercise electrocardiogram (ECG) as a firstline test. This indication was considered inappropriate according to ACC/AHA 2003 guidelines5; but it became a class IIa indication (appropriate, bwhere facilities, costs and personnel resources allowQ) following ESC 2006 guidelines,6 a reflection perhaps more related to current practice than evidence. Indeed, stress imaging techniques have several advantages over conventional exercise ECG testing including superior diagnostic performance for the detection of obstructive coronary artery disease and the ability to quantify and localize areas of ischemia. Although some evidence points toward the better reliance of a clinician on these data translating into more cost-effective decisions,26 other studies have shown that the extra diagnostic and prognostic value is limited in patients who are capable of exercise, with an interpretable resting ECG.27 Even if the more liberal scoring of ESC 2006 guidelines are adopted, the inappropriateness rate in our population remains at the concerning level of 14.5% (7% in center 2 and 22% in center 1). The recent publication of appropriateness criteria for nuclear cardiology, CT, and cardiac magnetic resonance1,3 represents an alternative approach to the use of guidelines used in this article. These guidelines were developed using a modified Delphi technique of independent assessment by a number of imaging and nonimaging experts. Although both involve some degree of expert opinion, the goal of the appropriateness criteria guidelines is to define reasonable
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practice, whereas the guidelines define optimal care. The data presented here reflect a bworst case scenario,Q and analysis of appropriateness criteria that are currently under development for stress echocardiography may provide a fresh perspective. Similarly, the appropriateness of testing in Europe and Australia, which have different health care systems from the United States, may not correspond to appropriateness at an American institution.
Limitations The approach to defining appropriateness from guidelines is simple, but is limited to defining the beffectivenessQ component of cost-effectiveness rather than quantifying the potential benefits against the costs of a particular diagnostic or therapeutic procedure for a given clinical problem, let alone a particular patient.10 Moreover, although an independent reviewer is essential, the information provided by the chart and request may be incomplete; and this process does not allow the evaluation of nuances according to the situation of the patient. For example, although a stress imaging test is not accepted as the appropriate first step for the diagnosis of coronary disease in women in guidelines,5,6 many clinicians feel uncomfortable with the lower accuracy of standard stress testing in women; and stress imaging tests have been selected as the appropriate first test for investigation of coronary disease in some settings.28 Finally, this simple strategy does not account for the differential cost-effectiveness of various noninvasive tests according to different levels of coronary artery disease probability and risk.28 Solutions to the problem of inappropriate testing At present, cardiac imaging is mostly performed on a pay-for-performance basis. In theory, the referring physician and the practicing physician are responsible for the appropriateness of the indication, from both the ethical and—at least in Europe—the legal viewpoint.9 In practice, economic induction, medicolegal pressure, and professional interest create the perfect storm of inappropriateness in the cardiac imaging laboratory. It is also well known that—in the words of Bernard Lown—btechnology in medicine is frequently untested scientifically, often applied without data relating to cost benefit, and driven by market forces rather than by patient needs.Q29 As a consequence, the bparadox of plentyQ is a major challenge to contemporary health care delivery: more resource use may lead to poorer measures of care. More is not necessarily better and, in fact, may be worse.30 A substantial abatement of inappropriateness could be achieved acting both upstream and downstream to the cardiac imaging laboratory. Upstream from the examination, the booking system should be remodeled. In many places, this is a passive, administrative channel
Picano et al 289
between the patient and a secretary. The lower levels of inappropriate testing in an environment where there is a screening or consultation step suggest that this more active, time-consuming, but critically important filter between the referring and the practicing physician is effective. Local guidelines to testing might be developed and implemented on the basis of general guidelines adapted to local expertise and technology available, and possibly implemented also on the basis of specific audit and training courses.30 In fact, lack of communication and imperfect exchange of information are often at the basis of inappropriateness in this rapidly evolving field. Downstream from the examination, the current systems pay for cardiac procedures regardless of their appropriateness. New payment models should be developed to pay physicians more for providing clearly appropriate procedures and substantially less for procedures of limited value. Although it is certain that this is more easily said than done, there is no doubt that a system paying the quality, not only the quantity, of the procedures would be an enormous boost to appropriateness.
References 1. Brindis RG, Douglas PS, Hendel RC, et al. ACCF/ASNC appropriateness criteria for single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI): a report of the American College of Cardiology Foundation Quality Strategic Directions Committee Appropriateness Criteria Working Group and the American Society of Nuclear Cardiology endorsed by the American Heart Association. J Am Coll Cardiol 2005; 46:1587 - 605. 2. Pennell DJ, Sechtem UP, Higgins CB, et al. Clinical indications for cardiovascular magnetic resonance [CMR]: consensus panel report. Eur Heart J 2004;25:1940 - 65. 3. Hendel RC, Patel MR, Kramer CM, et al. ACCF/ACR/SCCT/SCMR/ ASNC/NASCI/SCAI/SIR 2006 appropriateness criteria for cardiac computed tomography and cardiac magnetic resonance imaging: a report of the American College of Cardiology Foundation Quality Strategic Directions Committee Appropriateness Criteria Working Group, American College of Radiology, Society of Cardiovascular Computed Tomography, Society for Cardiovascular Magnetic Resonance, American Society of Nuclear Cardiology, North American Society for Cardiac Imaging, Society for Cardiovascular Angiography and Interventions, and Society of Interventional Radiology. J Am Coll Cardiol 2006;48:1475 - 97. 4. Armstrong WF, Pellikka PA, Ryan T, et al. Stress echocardiography: recommendations for performance and interpretation of stress echocardiography. Stress Echocardiography Task Force of the Nomenclature and Standards Committee of the American Society of Echocardiography. J Am Soc Echocardiogr 1998;11:97 - 104. 5. Gibbons RJ, Abrams J, Chatterjee K, et al. ACC/AHA 2002 guideline update for the management of patients with chronic stable angina—summary article: a report of the American College of Cardiology/American Heart Association Task Force on practice guidelines [Committee on the Management of Patients With Chronic Stable Angina]. J Am Coll Cardiol 2003;41:159 - 68.
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6. Fox K, Garcia MA, Ardissino D, et al. Guidelines on the management of stable angina pectoris: executive summary: the Task Force on the Management of Stable Angina Pectoris of the European Society of Cardiology. Eur Heart J 2006;27:1341 - 81. 7. Shaw LJ, Hachamovitch R, Berman DS, et al. The economic consequences of available diagnostic and prognostic strategies for the evaluation of stable angina patients: an observational assessment of the value of precatheterization ischemia. Economics of Noninvasive Diagnosis (END) Multicenter Study Group. J Am Coll Cardiol 1999;33:661 - 9. 8. Underwood S, Underwood SR, Godman B, et al. Economics of myocardial perfusion imaging in Europe—the EMPIRE Study. Eur Heart J 1999;20:157 - 66. 9. European Commission. Radiation protection 118: referral guidelines for imaging. http://europa.eu.int/comm/environment/radprot/ 118/rp-118en.pdf [accessed 10 January 2006]. 10. Grilli R, Magrini N, Penna A, et al. Practice guidelines developed by specialty societies: the need for a critical appraisal. Lancet 2000;355:103 - 6. 11. Regulla DF, Eder H. Patient exposure in medical X-ray imaging in Europe. Radiat Prot Dosimetry 2005;114:11 - 25. 12. Lucas FL, DeLorenzo MA, Siewers AE, et al. Temporal trends in the utilization of diagnostic testing and treatments for cardiovascular disease in the United States, 1993-2001. Circulation 2006;113:374 - 9. 13. Rodgers GP, Ayanian JZ, Balady G, et al. American College of Cardiology/American Heart Association Clinical Competence statement on stress testing: a report of the American College of Cardiology/American Heart Association/American College of Physicians–American Society of Internal Medicine Task Force on Clinical Competence. J Am Coll Cardiol 2000;36:1441 - 53. 14. Picano E. Sustainability of medical imaging. BMJ2004;328: 578 - 80. 15. Ayanian JZ. Rising rates of cardiac procedures in the United States and Canada: too much of a good thing? Circulation 2006;113: 333 - 5. 16. Picano E, Mathias Jr W, Pingitore A, et al. Safety and tolerability of dobutamine-atropine stress echocardiography: a prospective, multicenter study. Echo Dobutamine International Cooperative Study Group. Lancet 1994;344:1190 - 2. 17. Secknus MA, Marwick TH. Evolution of dobutamine echocardiography protocols and indications: safety and side effects in 3,011 studies over 5 years. J Am Coll Cardiol 1997;29:1234 - 40.
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18. Varga A, Garcia MA, Picano E. International Stress Echo Complication Registry. Safety of stress echocardiography (from the International Stress Echo Complication Registry). Am J Cardiol 2006;98:541 - 3. 19. Picano E. Informed consent and communication of risk from radiological and nuclear medicine examinations: how to escape from a communication inferno. BMJ 2004;329:849 - 51. 20. Anon. Pathology test—too much of a good thing. Lancet 1984;1:1278 - 9. 21. Medicare Payment Advisory Commission (MedPAC). Report to the Congress: growth in the volume of physician services. December 2004. Available at: http://www.medpac.gov/ publications/congressional_reports/December04_PhysVolume.pdf. 22. Lattanzi F, Magnani M, Cortigiani L, et al. Evaluation of appropriateness of prescribing echocardiography. Ital Heart JSuppl 32002;:613 - 8. 23. Herzog P, Rieger CT. Risk of cancer from diagnostic x-rays. Editorial comment. Lancet 2004;363:340 - 1. 24. Gontijo RV, Proietti FA, Amaral CF, et al. Appropriateness use of coronary angiography in patients with suspected ischemic heart disease in Brazil. Int J Cardiol 2005;104:348 - 9. 25. Gibbons RJ. Presidential opening address. US health care must change. Scientific sessions Sunday November 12th. Chicago, American Heart Association Meeting. 26. Marwick TH, Shaw L, Case C, et al. Clinical and economic impact of exercise electrocardiography and exercise echocardiography in clinical practice. Eur Heart J 2003;24:1153 - 63. 27. Severi S, Picano E, Michelassi C, et al. Diagnostic and prognostic value of dipyridamole echocardiography in patients with suspected coronary artery disease. Comparison with exercise electrocardiography. Circulation 1994;89:1160 - 73. 28. Shaw LJ, Marwick TH, Berman DS, et al. Incremental costeffectiveness of exercise echocardiography vs. SPECT imaging for the evaluation of stable chest pain. Eur Heart J 2006; 27:2448 - 58. 29. Lown B. A Cardiologist’s perspective on the crisis and challenges of biotechnology. Based on an address delivered at the 5th International Heart Health Conference in Milan, Italy on June 16, 2004, [http://www.procor.org/story.asp?storyid= Web17022313147procor71020041525&sitecode=procor& lang=L1&parentsec=S55§ion=S55&pn=1]. 30. Fisher ES. Medical care—is more always better? Editorial. N Engl J Med 2003;349:1665 - 7.
A gatekeeper for the gatekeeper: Inappropriate referrals to stress echocardiography Eugenio Picano, MD, PhD,a Emilio Pasanisi, MD,a Joseph Brown, BS,b and Thomas H. Marwick, MD, PhDb Brisbane, Australia; and Pisa, Italy
Background Cardiac imaging stress tests have increased nearly 3-fold in the last decade, with N10 million a year performed in the United States alone. Inappropriate selection for testing may have important consequences because small individual costs (and risks) multiplied by millions of examinations represent a significant societal burden. The aim of this study was to assess the appropriateness of selection for stress echocardiography in 2 high-volume laboratories. Methods This audit of 350 consecutive stress echocardiograms for evaluation of known or suspected coronary artery disease was performed from May to June 2006 at centers in Australia and Italy. Appropriateness was independently scored by a senior clinical cardiologist as follows: I = definitely appropriate, IIa = probably appropriate, IIb = probably inappropriate, or III = definitely inappropriate, based on current guidelines for cardiac stress testing. All referrals were accepted at one center, and referrals were prescreened by cardiology fellows working at the other. Results
Examinations were definitely appropriate in 217 (62%), probably appropriate in 35 (10%), probably inappropriate in 76 (22%), and definitely inappropriate in 22 (6%) patients. The main reasons of inappropriateness were (1) performance as first-line test (37% of inappropriate tests) and (2) test repeated too often in the absence of change in clinical status (30%). The inappropriate testing rate was higher when no screening of external referral was implemented (43% vs 13%, P b .0001).
Conclusions Inappropriate indications for stress echocardiography are common but avoidable if referrals are screened. Targeting inappropriateness opens a unique opportunity to cut health care expenditure with no reduction, and possibly improvement, in health care standards. (Am Heart J 2007;154:285290.) Noninvasive cardiac imaging with myocardial perfusion imaging,1 cardiovascular magnetic resonance,2 computed tomographic (CT) coronary angiography,3 and stress echocardiography4 may facilitate the selection of patients for invasive procedures and interventions.5,6 Although the diagnostic and prognostic information provided by these tests is itself not without cost—both financial and safety—some studies have shown that the use of noninvasive imaging in appropriately selected patients translates into cost savings because of more appropriate selection for even more expensive procedures.7,8 However, these studies have involved patients who were appropriately selected for testing; and the trade-off between costs and benefits will not be the same when studies are performed less appropriately.9,10 The problem of overuse of imaging tests is especially relevant in cardiology because cardiovascular imaging From the aDepartment of Medicine, Princess Alexandra Hospital, University of Queensland, Brisbane, Australia, and bCNR, Institute of Clinical Physiology, Pisa, Italy. Submitted March 1, 2007; accepted April 11, 2007. Reprint requests: Thomas H. Marwick, MD, PhD, Department of Medicine, Princess Alexandra Hospital, University of Queensland, Ipswich Road, Brisbane Qld 4102, Australia. E-mail: [email protected] 0002-8703/$ - see front matter D 2007, Mosby, Inc. All rights reserved doi:10.1016/j.ahj.2007.04.032
amounts for at least 50% of all imaging testing.11 In particular, imaging stress testing is rising at an impressive rate. In the United States, from 1993 to 2001, there was a nearly 3-fold increase in the use of imaging stress tests,12 reaching N9 million stress single photon emission CT (SPECT) myocardial perfusion imaging procedures in 2002.1 Although the number of stress echocardiograms is less—according to 1998 Medicare data, 1 stress echocardiogram was performed every 4 stress SPECT myocardial perfusion scans13—this also amounts to a substantial number of studies. Despite the immense benefits of this diffusion of stress imaging testing, the associated costs are very high and probably unsustainable at current levels.1,14 Guidelines established by credible societies and professional bodies form a reasonable basis for defining the appropriateness of testing. In this study, we sought to define the appropriateness of referral to stress echocardiography at expert centers in different health systems.
Methods Study design We audited 350 stress echocardiography examinations performed at the Institute of Clinical Physiology, Pisa, Italy, and the University of Queensland Cardiovascular Imaging group,
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286 Picano et al
Table I. Indications for testing at 2 centers Indication Asymptomatic Stable angina Nonspecific chest pain After ACS After revascularization Before major surgery Total
Class I
Class IIa
Class IIb
Class III
Total
12 54 54 38 15 44 217
11 6 12 1 5 0 35
18 10 33 1 11 3 76
11 1 4 0 5 1 22
52 71 103 40 36 48 350
ACS; Acute coronary syndrome.
Princess Alexandra Hospital, Brisbane, Australia—each center contributing 175 consecutive examinations. All indications were clinically driven and referred from a clinician through the outpatient clinic or inpatient wards. However, the general policy of test booking was different in the 2 contributing centers: center 1 directly accepted the referrals, whereas in center 2, requests were filtered by a cardiologist or trainee working in the laboratory.
Definition of appropriateness For all individual examinations, a senior clinical cardiologist independently reviewed clinical and imaging information relating to the request for testing, including review of the patient chart. The first step involved defining the frequency of inappropriate testing. Indications for testing were divided into 6 categories: asymptomatic, stable angina, nonspecific chest pain, postacute coronary syndrome, postrevascularization, and before major surgery. Within each category, the clinical presentation was used to define whether the clinical setting corresponded to an appropriate indication for stress echocardiography based on the latest (2003) specialty guidelines of the American College of Cardiology (ACC)/American Heart Association (AHA) for cardiac stress testing,5 as follows: I = definitely appropriate (the procedure should be performed; benefit { risk), IIa = probably appropriate (it is reasonable to perform the test; benefit J risk), IIb = probably inappropriate (procedure may be considered; benefit z risk), or III = definitely inappropriate (risk z benefit). The second step involved categorizing the causes of inappropriateness (in classes IIb and III), using groupings according to European Union Medical Imaging guidelines (2001), into one of 6 possible broad categories9: 1. Repeating investigations that have already been done (eg, at another hospital). 2. Investigation when results are unlikely to affect patient management (eg, because the anticipated bpositiveQ finding is usually irrelevant or because a positive finding is so unlikely). 3. Investigating too often (eg, before the disease could have progressed or resolved or before the results could influence treatment). 4. Doing the wrong investigation. 5. Failing to provide appropriate clinical information and questions that the imaging investigation should answer.
6. Excessive investigation. Some clinicians tend to rely on investigations more than others, and some patients have inappropriate expectations of the optimal type of examination.
Statistical analysis We expressed continuous data as mean F SD and dichotomous variables as percentages. We compared continuous data with unpaired-samples Student t test and proportions by the m2 statistics. We considered statistically significant a P value b .05.
Results Patient characteristics Starting from 1 May 2006, 350 consecutive patients (age = 62 F 7 years, 231 men) underwent stress echocardiography for the evaluation of known or suspected ischemic heart disease. The stress used was exercise (n = 187) or pharmacological (with dipyridamole or dobutamine in 38 and 125, respectively, patients unable to exercise). The clinical presentation of the 350 patients and the classes of indications broken down according to clinical status are listed in Table I. Appropriateness of testing Indications were partially or totally inappropriate in about 1 of 4 patients (Figure 1). The number of patients with positive stress echocardiograms was higher in the 252 patients with class I or IIa indication than in the 98 patients with class IIb or III indication (38.5% vs 9%, P = .0001). The major source of inappropriateness was a class IIb indication in patients with nonspecific chest pain or in those who are asymptomatic (Table I). The criteria for appropriateness are clearly a determinant of its prevalence. Nonetheless, even if the more bliberalQ scoring of the European Society of Cardiology (ESC) 2006 guidelines were adopted, the inappropriateness rate in our population remained at 14.5% (7% in center 2 and 22% in center 1). Reasons for inappropriate testing The reasons for inappropriateness in the 98 patients with class IIb or III indications are shown in Figure 2.
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Figure 1
Appropriateness rate of stress echo examinations. Overall appropriateness rate in the overall population of 350 patients recruited from the 2 centers.
The top 2 reasons of inappropriateness (classes IIb and III) were (1) 36 tests performed as first-line test (37% of all inappropriate tests) and (2) 29 tests performed in patients as a part of a regular follow-up program (after an acute event or mechanical revascularization) at 3- or 6-month interval (from the revascularization or previous stress echo) in the absence of any change in the clinical status (30% of all inappropriate tests). The inappropriateness rate was 3-fold higher in center 1 (Figure 3), accepting referrals without prescreening and filtering, which were routine parts of the policy of testing in center 2. The impact of less stringent criteria is shown in Figure 4.
Discussion The results of this audit of highly experienced stress echocardiography laboratories show that the number of costly examinations with inappropriate indication and/ or inadequate clinical utilization of test results is high. There is variability of test indication and patient selection between sites; and this seems to be based on local practice for test approval, with more inappropriate testing in the setting of open access to testing.
The risks and costs of inappropriateness Useless examinations pose an economic burden to society, restrict access to patients in need, carry acute risks without offering commensurate benefit, and do not increase (and possibly reduce) the quality of health care.14 In case of stress imaging, there is also a nonnegligible risk associated with the administration of
Picano et al 287
Figure 2
Sources of inappropriateness. Reasons of inappropriateness, as suggested by European Commission Medical Imaging guidelines, in the 98 patients (from centers 1 and 2) with class IIb or III indication to testing.
physical or pharmacological stress.15-18 By definition, risk is outweighed by benefit for appropriate, but not inappropriate, examinations, which should therefore be kept as low as possible also to minimize the litigation potential linked to development of complications during inappropriate testing.19 From the medicolegal viewpoint, according to the Euratom law, both the prescriber and the practitioner are responsible for the justification of the test exposing the patient to a potential risk. The problem of waste and inappropriateness in medical testing is neither new nor restricted to cardiovascular imaging. In the field of laboratory medicine, at least 1 of 3 examinations is deemed inappropriate.20 More than 20 years ago, a Lancet editorial complained of the bflooding of laboratory testingQ requested by clinicians who believe that ball seems to be for freeQ and often ask for bdiagnostic carpet bombingQ instead of carefully targeted, clinically driven testing.20 After 20 years, the same pattern seems to apply to cardiac stress imaging testing. However, the economic pressure has increased; and in an era of health care rationing, now the waste of resources can seriously endanger access to the benefit of sophisticated testing for those who are in real need. For a resting cardiac imaging test, the average cost (not charges) of an echocardiogram being equal to 1 (as a cost comparator), the cost of a CT is 3.1; a SPECT, 3.2; a cardiovascular magnetic resonance imaging, 5.51; a positron emission tomographic scan, 14.03; and a right and left heart catheterization, 19.95.2 For
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Figure 3
Figure 4
Interinstitutional differences based on ESC 2006 guidelines.
Interinstitutional differences based on AHA/ACC 2002/2003* guidelines. Intercenter variations in appropriateness rates on the basis of the policy of referral to testing. Appropriateness is higher for center 1, with pretesting screening of specialist cardiologist referral by a cardiology fellow.
stress cardiac imaging, compared with the treadmill exercise test equal to 1 (as a cost comparator), the cost of a stress echo is 2.1 and that of a stress SPECT scintigraphy is 5.7.5 In other words, the costs of useless examinations are immense. Not surprisingly, expenses for medical imaging are today one of the highest cost items in a health plan’s medical budget and also one of the fastest growing. Diagnostic imaging services reimbursed with Medicare’s physicians fee grew more rapidly than any other type of physician service from 1999 to 2003.21
Comparison with previous studies The relatively high rate of partially appropriate or frankly inappropriate examinations found for stress echocardiography in the present study is consistent with findings observed with a variety of imaging techniques. A recent survey of the Italian Association of Echocardiography showed that 50% of resting transthoracic echocardiograms are totally or partially inappropriate.22 The rate of inappropriateness is also considered to be about 30% for radiological testing.23 The inappropriateness rate of coronary angiography has been described to be as high as 65% in some tertiary care referral centers.24 Furthermore, in the field of stress radionuclide perfusion imaging, more costly than stress echocardiography and not without additional long-term risks due to the use of radiation. The inappropriateness rate was reported to be N20% in a high-volume nuclear medicine laboratory.25 Thus, the
appropriateness rate of stress echocardiography observed in the current study seems to be no exception to the pandemic of inappropriateness in modern imaging.9
Limitations of guidelines to define appropriate test selection The greatest proportion of inappropriate studies were due to the permissive use of stress imaging as an alternative to exercise electrocardiogram (ECG) as a firstline test. This indication was considered inappropriate according to ACC/AHA 2003 guidelines5; but it became a class IIa indication (appropriate, bwhere facilities, costs and personnel resources allowQ) following ESC 2006 guidelines,6 a reflection perhaps more related to current practice than evidence. Indeed, stress imaging techniques have several advantages over conventional exercise ECG testing including superior diagnostic performance for the detection of obstructive coronary artery disease and the ability to quantify and localize areas of ischemia. Although some evidence points toward the better reliance of a clinician on these data translating into more cost-effective decisions,26 other studies have shown that the extra diagnostic and prognostic value is limited in patients who are capable of exercise, with an interpretable resting ECG.27 Even if the more liberal scoring of ESC 2006 guidelines are adopted, the inappropriateness rate in our population remains at the concerning level of 14.5% (7% in center 2 and 22% in center 1). The recent publication of appropriateness criteria for nuclear cardiology, CT, and cardiac magnetic resonance1,3 represents an alternative approach to the use of guidelines used in this article. These guidelines were developed using a modified Delphi technique of independent assessment by a number of imaging and nonimaging experts. Although both involve some degree of expert opinion, the goal of the appropriateness criteria guidelines is to define reasonable
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practice, whereas the guidelines define optimal care. The data presented here reflect a bworst case scenario,Q and analysis of appropriateness criteria that are currently under development for stress echocardiography may provide a fresh perspective. Similarly, the appropriateness of testing in Europe and Australia, which have different health care systems from the United States, may not correspond to appropriateness at an American institution.
Limitations The approach to defining appropriateness from guidelines is simple, but is limited to defining the beffectivenessQ component of cost-effectiveness rather than quantifying the potential benefits against the costs of a particular diagnostic or therapeutic procedure for a given clinical problem, let alone a particular patient.10 Moreover, although an independent reviewer is essential, the information provided by the chart and request may be incomplete; and this process does not allow the evaluation of nuances according to the situation of the patient. For example, although a stress imaging test is not accepted as the appropriate first step for the diagnosis of coronary disease in women in guidelines,5,6 many clinicians feel uncomfortable with the lower accuracy of standard stress testing in women; and stress imaging tests have been selected as the appropriate first test for investigation of coronary disease in some settings.28 Finally, this simple strategy does not account for the differential cost-effectiveness of various noninvasive tests according to different levels of coronary artery disease probability and risk.28 Solutions to the problem of inappropriate testing At present, cardiac imaging is mostly performed on a pay-for-performance basis. In theory, the referring physician and the practicing physician are responsible for the appropriateness of the indication, from both the ethical and—at least in Europe—the legal viewpoint.9 In practice, economic induction, medicolegal pressure, and professional interest create the perfect storm of inappropriateness in the cardiac imaging laboratory. It is also well known that—in the words of Bernard Lown—btechnology in medicine is frequently untested scientifically, often applied without data relating to cost benefit, and driven by market forces rather than by patient needs.Q29 As a consequence, the bparadox of plentyQ is a major challenge to contemporary health care delivery: more resource use may lead to poorer measures of care. More is not necessarily better and, in fact, may be worse.30 A substantial abatement of inappropriateness could be achieved acting both upstream and downstream to the cardiac imaging laboratory. Upstream from the examination, the booking system should be remodeled. In many places, this is a passive, administrative channel
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between the patient and a secretary. The lower levels of inappropriate testing in an environment where there is a screening or consultation step suggest that this more active, time-consuming, but critically important filter between the referring and the practicing physician is effective. Local guidelines to testing might be developed and implemented on the basis of general guidelines adapted to local expertise and technology available, and possibly implemented also on the basis of specific audit and training courses.30 In fact, lack of communication and imperfect exchange of information are often at the basis of inappropriateness in this rapidly evolving field. Downstream from the examination, the current systems pay for cardiac procedures regardless of their appropriateness. New payment models should be developed to pay physicians more for providing clearly appropriate procedures and substantially less for procedures of limited value. Although it is certain that this is more easily said than done, there is no doubt that a system paying the quality, not only the quantity, of the procedures would be an enormous boost to appropriateness.
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