When Physicians Own or Lease MRIs, Back Scans and Surgery are More Likely

Patients of orthopedists are more apt to undergo back surgery as well, according to new findings.

Financial incentives, inherent in self-referral, "seem to have an influence on physician behavior that we can't ignore, and an impact on patient care in the long run," said Jacqueline Baras Shreibati, MD, of Stanford University School of Medicine (Stanford, CA, USA), the lead study author. The study's findings were published online April 2011 on Health Services Research.

There is no definitive evidence that either MRI or surgery for low back pain improve outcomes, according to the investigators. The study compared scan rates for the Medicare patients of 1,033 primary care physicians and 1,271 orthopedists, before and after the physicians acquired MRI equipment, by purchase or by entering into lease arrangements, whereby they billed directly for scans they ordered.

As earlier studies had shown, when physicians begin self-referral for MRI scanning they become considerably more likely to order scans: in this study the rate increased by 13% for orthopedists' patients, and 32% for patients of primary care doctors. Moreover, patients who visited an orthopedist after he or she had acquired an MRI were 34% more likely to undergo back surgery within six months.

The study's aim was not to evaluate whether the additional surgeries were necessary, according to Dr. Shreibati. However, it did reveal "a direct relationship from imaging to surgery--in a group of patients where surgery is very controversial."

Jean M. Mitchell, PhD, professor of public policy at Georgetown University (Washington DC, USA), said, "the main contribution of this research is what it shows about ‘cascade effects' of self-referral--its impact not just on the procedure itself, but things that happen as a result. If the patient hadn't had the MRI, they never would have had the back surgery."

US Federal regulations prohibit physicians from referring US Medicaid or Medicare patients for health services in which they have a financial interest, but make an exception for in-office procedures, which has been interpreted to include MRI scans performed with offsite equipment leased on a per-scan basis. "Medicare spending alone would go down about 25% if self-referral were really policed or eliminated," Dr. Mitchell said.

While the findings do not indicate that patients should question their doctors' recommendations, Dr. Shreibati remarked, "I think it's important for them to keep in mind that financial incentives may influence the care they receive."

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Stanford University School of Medicine
Georgetown University