Correspondence
Appropriateness of Coronary Angiography after Myocardial Infarction among Medicare Beneficiaries
N Engl J Med 2001; 344:774-775March 8, 2001
- Article
To the Editor:
In their article on the appropriateness of coronary angiography after myocardial infarction among Medicare beneficiaries (Nov. 16 issue),1 Guadagnoli et al. fail to acknowledge several important limitations of their study. First, the data are from 1994 and 1995. The way in which members of managed-care plans are served has changed radically since then, as have the practice patterns of cardiologists. To imply that we can now use the study's results to make decisions for 2001 and beyond is incorrect.
Second, the authors make no attempt to investigate the risk structures for the Medicare beneficiaries who were studied. Did they have capitated or partial-risk arrangements? Were the specialists actually paid on a full or discounted fee-for-service basis? Such questions go to the heart of the premise of the article: that a difference in care relates to a difference in the mechanisms for reimbursement. If, indeed, the majority of the specialists were being paid on a fee-for-service basis, it becomes more difficult to maintain that a patient's insurance status was primarily responsible for any variation in care received.
Third, the guidelines the authors use as the standard for evaluating the appropriateness of care were published in 1996 — almost two years after the first patients were treated.2 It is unclear how one can hold physicians accountable for guidelines that had not yet been released.
Medical practice, managed care, and indeed, our entire health care delivery system have changed dramatically in the six years since these patients were treated. This article may serve as an interesting historical piece, but its value as a contribution to the health services literature is minimal. Hindsight is always 20/20, but it makes for poor science.
2 ReferencesDerek van Amerongen, M.D.
Humana/ChoiceCare, Cincinnati, OH 452021
Guadagnoli E ,Landrum MB ,Peterson EA ,Gahart MT ,Ryan TJ ,McNeil BJ . Appropriateness of coronary angiography after myocardial infarction among Medicare beneficiaries: managed care versus fee for service. N Engl J Med 2000;343:1460-1466
Full Text | Web of Science | Medline2
Ryan TJ ,Anderson JL ,Antmen EM , et al. ACC/AHA guidelines for the management of patients with acute myocardial infarction. J Am Coll Cardiol 1996;28:1328-1428
CrossRef | Web of Science | Medline
To the Editor:
Guadagnoli and colleagues report less frequent use of coronary angiography among Medicare beneficiaries who were enrolled in managed-care plans than among those who had fee-for-service coverage. Their study explored potentially influential variables, including predictors of various types of care-providing behavior. More reliable conclusions could have been drawn had they assessed, or at least discussed, the role of patients' attitudes toward coronary angiography, since this procedure has potentially lethal complications and since the authors do not indicate the percentage of the variance that was explained by the model.
Although a service may be clinically appropriate, it may not be provided because the patient declines it or fails to give consent. Leape and colleagues1 reported a refusal rate for coronary-artery bypass grafting and percutaneous transluminal coronary angioplasty procedures that ranged between 5 percent for patients at hospitals with on-site revascularization facilities and 10 percent for patients at hospitals without such facilities, accounting for up to 25 percent of underuse. The rate of underuse of angiography found by Guadagnoli et al. among patients with American College of Cardiology–American Heart Association (ACC–AHA) class I indications was 63 percent for managed-care enrollees overall and 85 percent for such patients who were admitted to hospitals without angiography facilities; these figures represent significantly higher rates of underuse of coronary angiography than among fee-for-service beneficiaries (54 percent overall and 69 percent of those at hospitals without angiography facilities). These rates may be explained by differences in the attitudes of patients, in the ability of physicians to obtain informed consent, or in the attitude of physicians in cases in which patients are unable to give consent. Although some potentially predictive characteristics were considered (age, race or ethnic group, and some clinical variables), others such as cognitive status, educational level, financial status, and individual willingness to take risks might have provided important information and accounted for differences in behavior. Only interviews with the patients, however, would have enabled the authors to identify the distribution of patients who declined the procedures.
1 ReferencesAldo Mariotto, M.D.
Health Authority No. 6 Friuli Occidentale, 35100 Padua, Italy1
Leape LL ,Hilborne LH ,Bell R ,Kamberg C ,Brook RH . Underuse of cardiac procedures: do women, ethnic minorities, and the uninsured fail to receive needed revascularization? Ann Intern Med 1999;130:183-192
Web of Science | Medline
To the Editor:
Guadagnoli et al. report that of the more than 50,000 Medicare beneficiaries studied after acute myocardial infarction, 44 percent had ACC–AHA class I indications for angiography, although only 46 percent with fee-for-service coverage and 37 percent of managed-care enrollees with such indications underwent angiography. This article appears to suggest that, ideally, at least 44 percent of elderly patients who have had an acute myocardial infarction should receive angiography.
An earlier study by Tu et al.1 found that elderly Medicare patients were more likely to undergo coronary angiography than a similar population in Canada (34.9 percent vs. 6.7 percent), yet these two populations had identical one-year mortality rates.
I would be reluctant to recommend that the rate of angiography after myocardial infarction in Canada be increased by a factor of more than six to make it coincide with the recommendations for ACC–AHA class I. Perhaps we should demand far greater scientific scrutiny of ACC–AHA class I indications for angiography after myocardial infarction before we apply this standard to our patients.
1 ReferencesMichael G. Kaplan, M.D.
Maimonides Medical Center, Brooklyn, NY 112191
Tu JV ,Pashos CL ,Naylor CD , et al. Use of cardiac procedures and outcomes in elderly patients with myocardial infarction in the United States and Canada. N Engl J Med 1997;336:1500-1505
Full Text | Web of Science | Medline
Author/Editor Response
Dr. Guadagnoli replies:
To the Editor: Dr. van Amerongen suggests that, because data from the Cooperative Cardiovascular Project reflect care that was given in the mid-1990s, our results do not deserve serious attention. Despite their age, these remain the most representative and clinically rich data available with which to study the care given to Medicare patients with acute myocardial infarction. Our findings are valuable because they call attention to the need to monitor differences in quality with the use of more recent data, especially in the light of the serious financial difficulties that many managed-care organizations have faced in recent years. To state that differences in quality have disappeared simply because time has passed is to engage in speculation that requires validation.
Dr. van Amerongen also raises the issue of risk structures for patients enrolled in managed-care plans. Although the plans assumed all financial risk for patients, we did not have data that indicated how plans subsequently arranged payments to physicians. However, when we examined the performance of individual plans — an analysis that comes closer to addressing the issue raised by Dr. van Amerongen — we observed consistently lower rates of use of needed angiography for managed-care beneficiaries than for patients with fee-for-service coverage. The way in which financial relations between plans and providers influence quality is an important area for further investigation.
The 1996 guidelines1 represented the standard of care for patients with acute myocardial infarction during the period when our patients were hospitalized. Although the guidelines were published in 1996, they summarized research findings published earlier. Furthermore, the 1996 and 19902 versions of the guidelines are very similar with respect to the indications that define class I for the hospital management phase.
Dr. Mariotto suggests that differences in the preferences of patients with respect to angiography might help to explain differences in use. Such data were not available to us, but further work in this area is warranted.
Dr. Kaplan attempts to draw a parallel between our study and one that compared mortality rates for all types of patients with acute myocardial infarction who were treated in the United States and Canada and somehow concludes that ACC–AHA class I indications are not useful. We compared the unadjusted one-year mortality for patients assigned to class I who underwent angiography with the rate among those who did not undergo angiography. Thirty-seven percent of those who did not undergo the procedure were dead by one year, whereas only 15 percent of those who received it had died (P<0.001). Proper statistical adjustment may reduce the difference in mortality rates between these two groups but will most likely not eliminate it.
2 ReferencesEdward Guadagnoli, Ph.D.
Harvard Medical School, Boston, MA 02115-58991
Ryan TJ ,Anderson JL ,Antman EM , et al. ACC/AHA guidelines for the management of patients with acute myocardial infarction: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Acute Myocardial Infarction). J Am Coll Cardiol 1996;28:1328-1428
CrossRef | Web of Science | Medline2
Gunnar RM ,Bourdillon PD ,Dixon DW , et al. ACC/AHA guidelines for the early management of patients with acute myocardial infarction: a report of the American College of Cardiology/American Heart Association Task Force on Assessment of Diagnostic and Therapeutic Cardiovascular Procedures (Subcommittee to Develop Guidelines for the Early Management of Patients with Acute Myocardial Infarction). Circulation 1990;82:664-707
CrossRef | Medline
