Study: Self-referral MRIs result in more negative testing

Physician groups that own their MRI scanners not only order more tests, but those tests turn out to be negative more often than tests ordered by groups that don't own their own scanners, according to a study published in the September issue of the American Journal of Roentgenology.

According to lead author, Timothy Amrhein, M.D., from the Medical University of South Carolina, and his colleagues, the findings emphasize the impact self-referral has on image use, and how it remains a factor in any discussion on how to reduce healthcare costs.

For the study, the researchers reviewed 1,140 shoulder MRI scans between January and September 2009 ordered by two orthopedic groups in the same geographic area, one of which owned its own scanners and one of which did not.

They found that 255 of the 1,140 MRI scans turned out to be negative, and that the group that owned its own scanners performed 142 negative scans compared to 1,313 for the group that did not own its own machines. The result--a 25.6 percent difference--was statistically significant, the researchers said.

The researchers also found that there was no statistical difference in the number of lesions for every positive scan--1.67 for the group that owned its scanners compared to 1.71 for the group that did not. This, according to study co-author Ramsey Kilani, M.D., of Duke University, is significant, since one of the arguments made by physicians who self-refer is that their patients need immediate access to imaging because they are sicker.

"There are probably some scenarios in which that's true, but it didn't prove to be so in this study," Kilani told AuntMinnie.com. "The positive scans showed us that the patient groups were almost identical in their disease--rebutting the argument that the patients that physicians who have MRI scanners see are sicker."

To learn more:
- see the study in the American Journal of Roentgenology
read the article in AuntMinnie.com