MONDAY, Dec. 12 (HealthDay News) -- Patients who need steroid injections to ease lower back pain frequently undergo an MRI beforehand. But a new study finds that the expensive imaging tests have little or no clinical value for these patients.
Researchers at Johns Hopkins University School of Medicine found that the MRI does not typically improve results for patients who are candidates for the injection, and it has only a minor effect on doctors' decision-making.
"More is not necessarily better," said study researcher Dr. Steven P. Cohen, an associate professor of anesthesiology and critical care medicine at Hopkins.
The study is published online Dec. 12 in the Archives of Internal Medicine.
Lower back pain is one of the top three reasons people seek medical attention in the United States, and epidural steroid injections are the most common treatment at U.S. pain clinics. The injections deliver cortisone directly into the spinal canal to ease inflammation and pain.
Indiscriminate use of MRIs, which cost about $1,500 each, prior to injection greatly adds to soaring health costs associated with back pain, the authors say.
The American College of Physicians recommends MRIs for injection candidates only when underlying conditions, such as fractures or tumors, are suspected. The American College of Occupational and Environmental Medicine recommends the imaging only when certain persistent neurologic symptoms fail to improve, according to background information in the study.
Trying to assess the value of pre-injection MRI, Cohen evaluated 132 patients -- average age 52 -- treated at one of several pain clinics in the United States for sciatica. This is a painful condition in which the root of the sciatic nerve at the bottom of the spinal column is compressed or pinched.
Patients were assigned to two groups. Both groups got MRIs. In one group, the patients' doctors did not see the MRI results. In the other group, the doctor had the MRI results before deciding on treatment.
Overall, treatment barely differed, and three months later, both groups reported similar improvement in pain and functioning. Thirty-five percent in the group whose doctor didn't know the MRI results reported a positive outcome, compared with 41 percent of those whose doctors saw the MRI.
The reason may be because abnormal findings on the MRI and symptoms don't correlate much, Cohen said. Many middle-aged people who don't have back pain will have abnormal findings on the MRI.
While Cohen advocates against routine use of MRIs, he sees their value in certain cases. They should still be done, he said, when there are risk factors for serious problems. For example, an elderly woman who has fallen and may have a fracture of the vertebrae should have the MRI, he said.
Other research has found that doctors who have a financial interest in the imaging equipment are more likely than others to order the tests. Duke University Medical Center researchers looked at 500 lumbar spine MRI results ordered by two groups of doctors. One group had a financial interest in imaging equipment; the other did not.
They found 86 percent more negative scans -- indicating the test wasn't needed -- in the financial-interest group. They reported the findings at the 2011 Radiological Society of North America meeting.
Dr. Richard Deyo, a professor of family and internal medicine at Oregon Health and Science University in Portland and co-author of a commentary accompanying Cohen's study, said it's important to remember that "only a relatively small fraction of the people who get low back pain" will need the injection.
"It may be premature to suggest we stop doing MRIs for these patients," Deyo said. "Maybe the answer is to be more selective about who needs the injection." Better patient selection might naturally reduce the number of MRIs ordered, he said.
To learn more about epidurals for back pain, visit the U.S. National Institutes of Health.
SOURCES: Steven P. Cohen, M.D., associate professor, anesthesiology and critical care medicine, Johns Hopkins University School of Medicine, Baltimore, Md.; Richard Deyo, M.D., M.P.H, professor of family and internal medicine, Oregon Health and Science University, Portland; Dec. 12, 2011, online, Archives of Internal Medicine1>
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