Key messages
For radicular low back pain:
– systemic corticosteroids may have small benefits on pain and function soon after treatment (short-term follow-up), and might improve function for a while after treatment (long-term follow-up);
– benefits appear small, but systemic corticosteroids may be useful as they have few side effects when used for a short period of time, are widely available, and have low costs; systemic corticosteroids probably do not help avoid surgery;
– it is unclear whether effectiveness of systemic corticosteroids varies according to the duration of symptoms as optimal dose and duration of treatment for radicular low back pain is unknown; avoiding higher doses may reduce risk of harms.
For non-radicular back pain and spinal stenosis:
– benefits of systemic corticosteroids are unclear.
What is low back pain and how is it treated?
Systemic corticosteroids are anti-inflammatory medicines that work throughout the body. In people with radicular low back pain (sciatica, or back pain with leg pain related to a pinched nerve in the back, usually from a slipped or bulging disc), corticosteroids may relieve pain by decreasing swelling and related compression from slipped or bulging discs, thereby reducing pressure on the affected nerves. Other types of back pain (such as 'non-radicular' [or without nerve involvement] or back and leg pain due to spinal stenosis [narrowing of the spine]) may also have an inflammatory component that could respond to systemic corticosteroids.
What did we do?
We searched medical databases for clinical trials comparing corticosteroids versus placebo (dummy treatment) or no corticosteroids in adults with low back pain. We compared and summarized their results, and rated our confidence in the evidence, based on factors such as study methods and sizes.
What did we find?
We included 13 studies with 1047 people. Six studies were conducted in the US, four in Europe, one in Australia, one in Brazil, and one in Iran. Nine studies evaluated people with radicular low back pain, two studies evaluated people with non-radicular low back pain, and two studies evaluated people with spinal stenosis. In five studies, back pain was of short duration and in the other studies the duration of back pain was longer or mixed. The average age of people in the studies ranged from 36 to 47 years, except for the studies of spinal stenosis, where the average age was about 58 years. Pain scores before treatment were about 6.6 to 9.0 points on a scale of 0 to 10. The dose and length of treatment with systemic corticosteroids or placebo varied across studies.
Main results
For radicular low back pain, systemic corticosteroids appear to slightly reduce pain in the short term and allow resumption of normal activities, and might slightly improve people's ability to perform normal activities at long-term. Systemic corticosteroids probably do not reduce the likelihood of undergoing surgery to remove a slipped or bulging disc and had no impact on quality of life.
For other types of low back pain (non-radicular low back pain or spinal stenosis), the effects of systemic corticosteroids were unclear or suggested no benefit.
In the doses given in the studies, systemic corticosteroids for low back pain did not appear to cause serious harms, but evidence was limited.
What are the limitations of the evidence?
For radicular low back pain, we are moderately confident about effects on short-term pain, short-term function, long-term function (but based on only one study), likelihood of surgery, and short-term quality of life. For spinal stenosis, we are moderately confident only about effects on short-term pain and function. For other time points and outcomes and for non-radicular low back pain, we have little confidence about the evidence. Factors that decreased confidence in findings included flaws in how the studies were designed (patients were not assigned to treatments randomly, a lot of patients dropped out of the study, or there were large differences between patients assigned to different treatments), not having enough studies or participants to be certain about the results, and variations between studies in results and methods.
For people with radicular low back pain, studies are needed to determine the optimal dose and duration of systemic corticosteroid therapy, how effectiveness varies according to symptom duration, and whether imaging is needed to confirm the diagnosis of a bulging or slipped disc before using systemic corticosteroids. Studies are also needed to clarify effects of systemic corticosteroids on quality of life, long-term outcomes, and harms.
For people with non-radicular low back pain or spinal stenosis, research showing that some people have an inflammatory component would be helpful to determine whether well-designed clinical trials should be conducted, and which people should be included in them.
How up to date is this evidence?
The evidence is current to September 2021.
Systemic corticosteroids appear to be slightly effective at improving short-term pain and function in people with radicular low back pain not due to spinal stenosis, and might slightly improve long-term function. The effects of systemic corticosteroids in people with non-radicular low back pain are unclear and systemic corticosteroids are probably ineffective for spinal stenosis. A single dose or short course of systemic corticosteroids for low back pain does not appear to cause serious harms, but evidence is limited.
Corticosteroids are medications with anti-inflammatory and immunosuppressant properties. Systemic corticosteroids administered through the oral, intravenous, or intramuscular routes have been used to treat various types of low back pain, including radicular back pain (not due to spinal stenosis), non-radicular back pain, and spinal stenosis. However, there is uncertainty about the benefits and harms of systemic corticosteroids for low back pain.
To evaluate the benefits and harms of systemic corticosteroids versus placebo or no corticosteroid for radicular low back pain, non-radicular low back pain, and symptomatic spinal stenosis in adults.
We used standard, extensive Cochrane search methods. The latest search date was September 2021.
We included randomized and quasi-randomized trials in adults of systematic corticosteroids versus placebo or no corticosteroid.
We used standard Cochrane methods. The major outcomes were pain, function, need for surgery, serious adverse effect, and presence of hyperglycemia. The minor outcomes were quality of life, successful outcomes, non-serious adverse events, and withdrawal due to adverse events. We used GRADE to assess the certainty of evidence for each outcome.
Thirteen trials (1047 participants) met the inclusion criteria. Nine trials included participants with radicular low back pain, two trial with low back pain, and two trials with spinal stenosis. All trials blinded participants to receipt of systemic corticosteroids. Seven trials were at low risk of bias, five at unclear risk, and one at high risk of selection bias. Two trials were at high risk of attrition bias. Doses and duration of systemic corticosteroid therapy varied.
Radicular low back pain
For radicular low back pain, moderate-certainty evidence indicated that systemic corticosteroids probably slightly decrease pain versus placebo at short-term follow-up (mean difference (MD) 0.56 points better, 95% confidence interval (CI) 1.08 to 0.04 on a 0 to 10 scale) and may slightly increase the likelihood of experiencing improvement in pain at short-term follow-up (risk ratio (RR) 1.21, 95% CI 0.88 to 1.66; absolute effect 5% better (95% CI 5% worse to 15% better).
Systemic corticosteroids may not improve function at short-term follow-up (standardized mean difference (SMD) 0.14 better; range 0.49 better to 0.21 worse) and probably increase the likelihood of improvement in function at short-term follow-up (RR 1.52, 95% CI 1.22 to 1.91; absolute effect 19% better, 95% CI 8% better to 30% better). Systemic corticosteroids were associated with greater improvement in function versus placebo at long-term follow-up (MD −7.40, 95% CI −12.55 to −2.25 on the 0 to 100 Oswestry Disability Index) and greater likelihood of functional improvement (RR 1.29, 95% CI 1.06 to 1.56), based on a single trial. There was no difference in likelihood of surgery (RR 1.00, 95% CI 0.68 to 1.47).
Evidence indicated that systemic corticosteroids (administered as a single dose or as a short course of therapy) are not associated with increased risk of any adverse event, serious adverse events, withdrawal due to adverse events, or hyperglycemia, but estimates were imprecise as some trials did not report harms, and harms reporting was suboptimal in trials that did provide data. Limitations included variability across trials in interventions (e.g. corticosteroid used, dose and duration of treatment), clinical settings, and participants (e.g. duration of symptoms, methods for diagnosis); limited utility of subgroup analyses due to small numbers of trials; methodologic limitations or suboptimal reporting of methods by some trials; and too few trials to formally assess for publication bias using graphical or statistical tests for small sample effects.
Non-radicular low back pain
Evidence on systemic corticosteroids versus placebo for non-radicular pain was limited and suggested that systemic corticosteroids may be associated with slightly worse short-term pain but slightly better function.
Spinal stenosis
For spinal stenosis, limited evidence indicated that systemic corticosteroids are probably no more effective than placebo for short-term pain or function.