Two Dartmouth Studies Report Unnecessary Testing

The study shows a similar story for imaging stress tests. In Orlando, the one-year retest percentage was 24.2% and the three-year retest percentage was 53.8%, but in Portland, those comparative percentages were 11% and 29.8%, respectively.

The authors, led by H. Gilbert Welch, MD, a general internist at the White River Junction VA Medical Center and a Dartmouth Institute professor, said that the testing practices they examined have high-risk factors for "incidental detection and overdiagnosis." Testing above what is needed adds to costs, and may prevent other patients from getting the diagnostic workups they really should have, they said.

"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," they wrote. "This finding raises the question whether some physicians are routinely repeating diagnostic tests."

"Tests that are routinely repeated following a brief period require that more capacity (more diagnostic equipment, such as imaging systems and more personnel) must be in place to be able to provide access for new patients," Welch and colleagues wrote, adding that "short intervals to repeat testing also raise costs."

Wide variations in pulmonary function, chest computed tomography, cystoscopy, and upper endoscopy were also found. For example, pulmonary function tests were repeated within one and three years in 39.2% and 56.6% of Medicare beneficiaries, respectively, in Detroit, but in 28.8% and 39.4% of beneficiaries in San Francisco.