SPRINGFIELD, Massachusetts—Epidural steroid injections for chronic back pain are a big ticket item in the US, accounting for over $50 million a year in Medicare part B costs alone. A new assessment of this approach by the American Academy of Neurology's therapeutics and technology assessment subcommittee suggests that much of that money is probably wasted.

"We noted that the data did not support a role for the use of epidural steroid injections for long-term lumbosacral radicular pain relief or for the purpose of avoiding surgery, and that their use did not appear to impact long-term outcome in terms of function. The utility for short-term pain relief is limited in terms of the extent of relief attained." —Carmel Armon, MD, MHS.
Based on the available evidence, the AAN panel concludes that in general, epidural steroid injection for radicular lumbosacral pain does not impact average impairment of function, impact need for surgery, nor provide long-term pain relief beyond 3 months. Their routine use for these indications is not recommended. The report is published in the March 6, 2007, issue of Neurology.1

Systematic review shows limited brief relief, no lasting benefit

Lead author Carmel Armon, MD, MHS, and colleagues conducted a systematic literature review of studies of epidural steroid injections via Medline and via the Cochrane database. They found 37 studies, four of which met inclusion criteria. The researchers also included two studies that were not found on Medline, for a total of six in the analysis. Some studies combined the epidural with a local numbing agent and used the anesthetic or saline as a control. Other studies compared the steroid injections with saline. Dr. Armon is chief of neurology at Bayside Medical Center in Springfield, Massachusetts, and professor of neurology at Tufts University School of Medicine in Boston.

The reviewers' criteria for "higher quality evidence" include rigorous case definition, use of either placebo or active controls, use of a standardized efficacy scale, masking of patient and evaluator regarding treatment, safety data on all treatment arms, and data that permit calculation of the number needed to treat (NNT) to make one more patient better with treatment than with control.

Dr. Armon reports that epidural steroid injections might result in some improvement in radicular lumbosacral pain between 2 and 6 weeks after the injection, compared to control, but that there is no benefit at 24 hours, either no difference or rebound worsening at 3 and 6 months, and no difference at 1 year.

"We noted that the data did not support a role for the use of epidural steroid injections for long-term lumbosacral radicular pain relief or for the purpose of avoiding surgery, and that their use did not appear to impact long-term outcome in terms of function," Dr. Armon told CIAOMed. "The utility for short-term pain relief is limited in terms of the extent of relief attained."

Questions remain

Dr. Armon also pointed out that the available data do not show what percentage of patients will attain meaningful relief, and this makes calculation of NNT impossible. "The available data do not provide a direct comparison of epidural steroid injections to alternative short-term pain relief measures," he said. "The new study did not address whether surgery is a good option for treating radiating lumbosacral pain for all patients or some patients."

Dr. Armon said other questions that remain include: Which patients might benefit most from epidural steroid injections? How should a successful outcome be defined? What is the percentage of successful outcomes? What is the long-term outcome of surgery compared to alternatives?

Benefits of epidural steroids more limited than expected

"Our findings provide evidenced-based guidance regarding the potential for clinical effectiveness of these injections. Since this appears to be perhaps more limited than one might have imagined given the frequency with which these injections appear to be recommended and performed, those who are recommending and/or performing these injections may want to consider our findings when evaluating not only patients [other than those] who have undergone this procedure," study coauthor Charles E. Argoff, MD, director of the Cohn Pain Management Center at North Shore University Hospital in Manhasset, New York, told CIAOMed. Dr. Argoff said that although epidural steroid injections play an important role in the management of a subset of patients with low back pain, the results of this review ought to temper expectations of long-term relief.

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Reference

1. Armon CM, Argoff CE, Samuels J, et al. Assessment: Use of epidural steroid injections to treat radicular lumbosacral pain. Neurology. 2007;68:723-729.