When a diagnostic test result is negative, usually it’s cause for relief. But when the preliminary results of a study showed that nearly 9 in 10 MRI scans were negative, eyebrows were raised.
Not because the test results were questionable, but because of who owned the equipment used to conduct them. As described in a story on MedPage Today, the study, presented at a meeting of the Radiological Society of North America, involved patients who were sent for testing by physicians who had a financial interest in the MRI equipment.
It also showed that doctors with a financial stake in the device referred much younger patients for the test than those referred by practitioners who did not benefit financially from use of the imaging equipment.
It’s a pretty straight line from that set of data to conclude that docs with a financial interest in the medical device might be ordering unnecessary scans. So said the researchers. We have written about such conflicts of interest as well.
Increased spending on diagnostic imaging, one researcher noted, is due to several factors: imaging technology has improved, patients demand its use and clinicians are practicing defensive medicine (that is, ordering tests that might be of questionable need or usefulness in an effort to suppress lawsuits if somebody experiences an unwelcome outcome — a concept that many of us challenge as more myth than reality). Two-thirds of the cost of imaging tests goes to the physician-owners, of whom only 1 in 3 is a radiologist. Hospitals and other providers get the rest.
That’s why the researchers decided to study whether nonradiologist clinicians who owned scanning devices were more likely to order imaging tests for, in this case, lumbar spine scans.
They reviewed charts for 500 such cases. Some of these patients were seen at a medical practice with a financial stake in the MRI and some were seen at one that did not. All scans were read by radiologists with no financial interest in the equipment.
They found no difference in the average number of lesions among scans that were positive (meaning that the severity of the problem was the same in both groups). The difference in the number of negative scans order by doctor-owners, however, was astounding. And the age difference in patients for that group was notable as well-they were more than seven years younger on average.
“We’re not saying these studies are necessarily unnecessary, but when there’s a clear difference between the scans ordered for these two groups, and the only difference is whether the [clinician] owns the scanner, that makes you think there’s a tie,” said one physician who served as an adviser on the research. “We’re not sure if it’s conscious or unconscious.”
“Still,” he said, “if the positives are the same, but one group has more negative scans, then at a minimum you have to wonder what the reason for ordering that scan is.”
Yes, you do. You need, he said, stricter and more transparent information about scanner ownership. You need to re-examine federal Stark laws, which regulate physician self-referral of Medicare and Medicaid patients. Stark allows these programs to pay physicians for tests if the devices used are in their offices. You need, he said, to figure out ways to slow the growth of medical costs.
One way is to know whose pockets are lined when tests are prescribed that might not be necessary to solve a problem someone might not even have.