Additional MRI machines may lead to increase in back surgeries

Patients reporting new low-back pain are more likely to undergo surgery if treated in a locale containing a higher-than-average concentration of MRI machines, according to research from the Stanford University School of Medicine.

This may be bad news for patients, since some previous studies have suggested that increased surgery rates do not necessarily improve patient outcomes, the researchers stated in a press release.

“The worry is that many people will not benefit from the surgery, so heading in this direction is concerning,” senior author Laurence Baker, PhD, professor of health research and policy, said in the press release.

In their new study, published online Oct. 14 in Health Affairs, Baker and first author Jacqueline Baras, MHS, correlated areas with high numbers of MRI machines to an increased likelihood that MRIs will be performed on new patients with low-back pain. In turn, high local MRI availability correlates with increased rates of low-back surgery.

“It is important that policymakers recognize that infrastructure matters, and that the number of MRI machines in any particular area may affect the volume and quality of health care that patients receive,” Baras said in the press release.

Low-back pain was the fifth-most common reason for physician visits in the United States, with 26.4% of adults reporting low-back pain for a day or more during a 3-month period in 2002. More than 80% of low-back pain was diagnosed as nonspecific, a category that includes lumbar strains and sprains, degenerative disc disease and spinal instability, according to the press release.

Unnecessary surgery?

MRIs visualize the body’s internal structure and allow doctors to rule out some specific causes of back pain. However, MRIs may also detect anomalies unrelated to back pain, prompting doctors to perform surgery that may not benefit the patient, the authors noted.

To determine how MRI technology influences patient treatment, the researchers collected data on traditional Medicare patients who received care for nonspecific low-back pain from 1998 to 2005. Patient data were linked with the number of MRI machines in the area. The areas of MRI availability were then divided into four groups, from high to low, and the incidence of MRI scans and surgeries were determined in each group.

Researchers projected that in 2004, there would have been 5.4% fewer low-back MRIs and 9% fewer back surgeries if all Medicare patients reporting new-onset low-back pain had been living in the areas of lowest MRI availability, according to the press release.

Performing MRI sooner

Two-thirds of the MRI scans that appear to result from increased availability happened within the first month of pain onset. Clinical guidelines recommend delaying MRI use until 4 weeks after onset, during which time most low-back pain patients show spontaneous improvement.

“Not only are patients in high-availability areas getting more MRIs, but they are getting them earlier,” Baras said in the press release.

Between 2000 and 2005, the MRI availability in the United States more than tripled, from 7.6 machines per 1 million persons to 26.6 machines. Each machine costs more than $2 million and one low-back scan costs $1,500. Increased rates of scans and surgeries are increasing the cost to treat low-back pain, the authors said.

“The big issue is how we handle new and exciting technologies in ways that allow us to reap the benefits of medical advances without letting all of our new things generate waste or, worse, [cause] actual reductions in patient well-being,” Baker said in the press release.