Between 30 and 50 percent of lumbar spine MRIs conducted through the Department of Veterans Affairs are inappropriate, according to a study by researchers at the School of Medicine and the VA.

The study, published online Feb. 2 in The American Journal of Managed Care, examined all lumbar spine MRIs prescribed in the entire VA system in fiscal year 2012.

“This imaging modality is widely used and, in many cases, used inappropriately,” said Risha Gidwani, DrPH, lead author of the study and a health economist at the VA Health Economics Resource Center and an associate at Stanford Health Policy.

These MRI scans are used to diagnose the source of lower back pain, a condition that sidelines millions of Americans each year. But the best treatments for most cases of lower back pain are conservative. In many cases, they resolve on their own or with appropriate exercise within weeks, the study said. In addition, radiographic findings on MRIs are often unrelated to patient symptoms, and MRIs can lead to unnecessary treatments that don’t help patients feel better. Extra scans also rack up costs and lead to inefficient allocation of resources, Gidwani said.

Organizations including the American College of Physicians and the American Association of Neurological Surgeons have drawn attention to the need to reduce inappropriate use of MRIs in their “Choosing Wisely” campaign. The Centers for Medicaid and Medicare Services also developed guidelines that identify inappropriate lumbar spine MRIs. These guidelines specify what conditions warrant an immediate MRI, including HIV, trauma, cancer or spinal surgery. In all other cases, the guidelines recommend visits with a physician to evaluate and manage the condition and physical therapy or chiropractic care in the 28 to 60 days before ordering an MRI.

‘Defensive Medicine’
Several hypotheses have been suggested to explain the overuse of lumbar spine MRIs, Gidwani said. Fee-for-service physicians could be trying to add to their bottom line, or physicians could be practicing defensive medicine, seeking to avoid lawsuits, she said. To investigate this, she and her colleagues studied ordering decisions in the VA, where physicians are salaried and largely shielded from malpractice concerns.

Using the most permissive parameters — for which a visit to any physician for any reason preceding an MRI was considered management for lower back pain — the researchers found 31 percent of lumbar spine MRIs were inappropriate. Within the VA alone, those inappropriate scans cost $13.6 million. By limiting the definition of “appropriate” to only cases in which the physician appointment had a billing code for “lower back pain,” the percentage of inappropriate scans skyrocketed to 53 percent. The real figure lies somewhere in the middle, Gidwani said.

“It’s possible, and even probable, this percentage is even higher outside the VA,” Gidwani said. “This study provides evidence this needs to be studied in different health-care environments where financial incentives may exacerbate the problem.”