When is too much of a good thing not so good?
A study by Dartmouth College and just published by the Archives of Internal Medicine shows that certain diagnostic tests are frequently repeated among Medicare beneficiaries -- and are not always in the interests of patient care, said one of the study's authors, Dr. H. Gilbert Welch.
While the study did not delve into the reasons why doctors repeat the same diagnostic tests, Welch said one likely reason is that doctors may simply find it easier to just repeat the test -- for which they will be paid -- than to retrieve the previous test results. Another reason, he said, is that sometimes they have the expensive testing equipment on hand and retesting is a "useful way to generate income."
But repeating tests that don't need to be repeated is expensive and a "major determinant" in rising health care costs, he said. He described the study as the first to discover the pattern of repeating diagnostic tests. He declined to put a dollar amount on the excessive testing.
The study reviewed tests such as echocardiography, puliminary function tests, endoscopy and CT scans of the chest -- all common diagnostic tests. Sometimes when there is a switch in doctors, the new doctor prefers to conduct his or her own testing regiment out of concern about malpractice accusations and the quality of the previously conducted test. But is it actually necessary?
"Sometimes it's just easier to repeat the test than to find the old results," Welch said. He said the practice of test repetition was most frequent in parts of Florida.
"We examined repetitive testing for six commonly performed diagnostic tests in which repeat testing is not routinely anticipated. Although we expected a certain fraction of examinations to be repeated, we were struck by the magnitude of that fraction: One-third to one-half of these tests are repeated within a three-year period. This finding raises the question whether some physicians are routinely repeating diagnostic tests," the authors note.
The study results indicate that among Medicare beneficiaries, undergoing echocardiography (examination of the heart), 55 percent had a second test within three years. Repeat testing for the other examinations also was common: 44 percent of imaging stress tests were repeated within three years, as were 49 percent of pulmonary function tests, 46 percent of chest computed tomography, 41 percent of cystoscopies (an examination of the bladder), and 35 percent of upper endoscopies (examination of the digestive tract), according to a release on the study.
"In conclusion, diagnostic tests are frequently repeated among Medicare beneficiaries. This has important implications not only for the capacity to serve new patients and the ability to contain costs but also for the health of the population. Although the tests themselves pose little risk, repeat testing is a major risk factor for incidental detection and overdiagnosis. Our findings should foster further research in this unstudied area," the authors conclude.