Overuse of imaging for cardiac stress tests harms patients and cost the healthcare system $501 million each year, according to a recent study published in the Annals of Internal Medicine.1
Excess imaging causes 491 additional cases of cancer each year, claims the study, which was conducted by researchers from NYU Langone Medical Center. Lead author Joseph Ladapo, MD, PhD, assistant professor in the departments of medicine and population health, told Evidence-Based Oncology that these cancers are largely preventable; while other public health initiatives could save more lives, few are as straightforward to implement as ending unnecessary radiation exposure.
“We’re not counting on someone quitting smoking, which is hard to do,” he said. “We just need to use radiological imaging only when it’s necessary, and avoid those cases when it’s clearly unnecessary,” he said.
In cardiac care, radiology is frequently an “addon” to a treadmill stress test, Ladapo explained. During the 1990s, use of imaging for cardiac stress testing “just skyrocketed,” he said, and only in the last few years have concerns about costs and patient safety entered the conversation.
The numbers reported in the NYU study are eye-catching even without the researchers’ analysis. Authors used data from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey to first highlight the overall rise in cardiac stress testing between 1993 and 2010.
Over this 18-year period, the average annual rate of ambulatory visits in the United States that resulted in a cardiac stress test being ordered or performed rose from 28 per 10,000 visits among adults without coronary heart disease (CHD) during 1993 to 1995, to 42 per 10,000 visits during 2001 to 2003, and to 45 per 10,000 visits during 2008 to 2010. Cardiac stress tests with imaging comprised a growing portion of those tests, rising from 59% during 1993 to 1995, to 87% during 2008 to 2010.1
Researchers then evaluated the appropriateness of the tests, based on criteria from the American College of Cardiology (ACC), the American Society of Nuclear Cardiology (ASNC), and the American Society of Echocardiography. Generally, researchers considered a test inappropriate if it was ordered for a patient without chest pain or angina, or if the patient had ischemic equivalents (including jaw or shoulder pain, palpitations, and dyspnea), CHD risk equivalents, electrocardiogram abnormalities, or syncope. From this analysis, researchers determined that at least 34.6% of the tests, numbering 1 million, were probably inappropriate.1
All this unwarranted imaging points to broader challenges in healthcare, Ladapo said. His findings and those of others—including a November 2013 study2 in The American Journal of Managed Care—highlight concerns that overtaxed primary care physicians are relying less on the physical exam, and more on diagnostic tests, to treat patients.
“People have less time. They are rushing. There’s less time to talk to patients and get a sense of their symptoms, and the alternative is testing,” Ladapo said. The process can “feed on itself,” he said, because unnecessary diagnostic tests using radiology can reveal incidental findings that may or may not be significant, but physicians will nonetheless feel compelled to investigate.
Lapado noted, as did the study itself, that adverse effects due to the overuse of imaging in cardiac stress testing is among the most frequently cited items in the Choosing Wisely campaign, the initiative of the ABIM Foundation to reduce wasteful tests and procedures across medical specialties.3 The harmful effect of radiology in cardiac stress testing is cited by the ACC, the ASNC, the American College of Physicians, and the American Academy of Family Physicians.1
He emphasized that cardiac stress testing is important—the issue is the manner in which it is conducted. “Cardiac stress testing is an important clinical tool,” Ladapo said. Not only will scaling back on imaging save healthcare costs, he said, but “Reducing unnecessary testing also will concomitantly reduce the incidence of radiation-related cancer.” To do this, physicians should rely upon ultrasound and treadmill tests, as well as a better physical exam.
If radiology is overused, it is important to ask why this occurs. As a follow-up to the results in Annals, Ladapo said he was planning to further investigate the 2013 study that appeared in AJMC, which found that the time pressures physicians face might cause some to rely more heavily on diagnostic tests, including radiology, rather than more time-consuming steps such as an extensive physical exam and patient history.2
“There are some scholars who are very concerned with how comfortable younger physicians are with the physical exam,” Ladapo said, explaining that medicine must “strike the right balance” between time spent with the patient and diagnostic tests, and not just for cost reasons.
Officials at Stanford’s medical school were so concerned with this issue that in 2007 they recruited Abraham Verghese, MD, MACP, to a special chair with a focus onteaching bedside medicine. In a 2010 interview, Verghese said that he was trained overseas, in the days before the MRI or the CT scan, when good examination skills were both essential and a source of pride. He also said that he believes that a good physical exam creates trust. “Patients know in a heartbeat if they’re getting a clumsy exam,” he said.5
A separate AJMC study published in 2012, which reviewed records from more than 85,000 patients, identified several patient-related factors that influenced their likelihood of having imaging. Among them: obesity, taking more than 10 medications, their gender, and whether they had congestive heart failure, diabetes, or hypertension. Among the physician factors affecting the likelihood of the use of imaging was the physician’s level of experience.4
Is there a role for patient education, so that physicians might have to explain why they are ordering imaging? Lapado believes there is, even though he knows some physicians are unhappy when a patient arrives for an appointment with an armful of printouts from the Internet. This doesn’t bother him. “More information usually helps them make a better decision,” he said. EBOReferences
1. Ladapo JA, Blecker S, Douglas PS. Physician decision making and trends in the use of cardiac stress testing in the United States: an analysis of repeated cross-sectional data. Ann Intern Med. 2014;161(7):482-490.
2. Stahl JE, Drew MA, Weilburg J, Sistrom C, Kimball AB. Face-time versus test ordering: is there a trade-off? Am J Manag Care. 2013;19(10 spec No.):SP362-SP368.
3. Choosing Wisely. An initiative of the ABIM Foundation. http://www.choosingwisely.org/. Accessed October 13, 2014.
4. Sistrom C, McKay NL, Weilburg JB, Atlas SJ, Ferris TG. Determinants of diagnostic imaging utilization in primary care. Am J Manag Care. 2012;18(4):e135-e144.
5. Grady D. Physician revives a dying art: the physical. The New York Times. http://www.nytimes.com/2010/10/12/health/12profile.html?_r=2&ref=health. Published October 11, 2010. Accessed October 13, 2014.