Are too many patients getting MRI scans for back pain?

Too many patients may be getting MRI scans for lower back pain, according to a study published in the April issue of the Journal of the American College of Radiology. The researchers tracked the number of MRI scans performed before conservative treatment takes place, a practice considered to be a sign of inappropriate use.

The study of Medicare beneficiaries showed a high percentage of patients undergoing MRI scans of the lumbar spine for lower back pain before they were given conservative treatment, with a significantly greater proportion of men imaged with no treatment than women. The percentages were similar among blacks and Hispanics who were imaged before treatment.

"Variations in use of conservative therapy according to factors other than clinically relevant factors, such as health status, are worrying," wrote co-authors Kimberly Lind, PhD, from Macquarie University in Sydney and Dr. Jonathan Flug from the Mayo Clinic in Phoenix. "Further strategies are needed to improve appropriateness and equity in the provision of diagnostic imaging."

Medicare uses an imaging efficiency metric known as OP-8 to determine the appropriateness of an MRI scan of the lumbar spine for low back pain. It is unclear, however, if public reporting of OP-8 compliance "has been effective in terms of changing MRI utilization and conservative therapy utilization based on the current literature," the authors wrote.

"The goals of this study were to evaluate OP-8 trends over time by site of service and to evaluate patient characteristics associated with not receiving conservative therapy for low back pain before imaging," Lind and Flug wrote. "We hypothesized that appropriate MRI use would be lower in sociodemographic groups that have historically faced limited access to care and would differ by site of service over time."

In their review of fee-for-service Medicare beneficiaries from 2009 through 2014, the researchers found 285,911 MRI scans of the lumbar spine. They excluded 195,488 MRI scans from the analysis because the beneficiary had an excluded condition or procedure before the MRI, leaving 90,423 OP-8 exams. Of that total, 56,141 MRI scans were performed after therapy and 34,282 scans were done with no prior therapy (JACR, April 2019, Vol. 16:4, pp. 560-569).

Lind and Flug found a statistically significant difference in the proportion of men (40%) and women (37%) undergoing MRI with no prior treatment (p < 0.0001). The results were similar among blacks and Hispanics, with approximately 40% also undergoing an MRI before therapy.

There was also evidence that the percentage of Medicare beneficiaries receiving conservative therapy before MRI has been on the rise in outpatient settings. The increases were "similar for outpatient hospitals that are subject to OP-8 reporting and for outpatient clinics that are not subject to OP-8 reporting, suggesting that OP-8 reporting is either ineffective or has spillover effects," they added.