Background: Existing guidelines and systematic reviews provide inconsistent recommendations on epidural corticosteroid injections for sciatica. Key limitations of existing reviews are the inclusion of trials with active controls of unknown efficacy and failure to provide an estimate of the size of the treatment effect.
Purpose: To determine the efficacy of epidural corticosteroid injections for sciatica compared with placebo.
Data sources: International Pharmaceutical Abstracts, PsycINFO, MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and CINAHL.
Study selection: Randomized, placebo-controlled trials assessing the efficacy of epidural corticosteroid injections in participants with sciatica.
Data extraction: Two independent reviewers extracted data and assessed risk of bias. Leg pain, back pain, and disability were converted to common scales from 0 (no pain or disability) to 100 (worst possible pain or disability). Thresholds for clinically important change in the range of 10 to 30 have been proposed for these outcomes. Effects were calculated for short-term (>2 weeks but ≤3 months) and long-term (≥12 months) follow-up.
Data synthesis: Data were pooled with a random-effects model, and the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach was used in summary conclusions. Twenty-five published reports (23 trials) were included. The pooled results showed a significant, although small, effect of epidural corticosteroid injections compared with placebo for leg pain in the short term (mean difference, -6.2 [95% CI, -9.4 to -3.0]) and also for disability in the short term (mean difference, -3.1 [CI, -5.0 to -1.2]). The long-term pooled effects were smaller and not statistically significant. The overall quality of evidence according to the GRADE classification was rated as high.
Limitation: The review included only English-language trials and could not incorporate dichotomous outcome measures into the analysis.
Conclusion: The available evidence suggests that epidural corticosteroid injections offer only short-term relief of leg pain and disability for patients with sciatica. The small size of the treatment effects, however, raises questions about the clinical utility of this procedure in the target population.
Primary funding source: None.