Analgesic effects of treatments for non-specific low back pain: a meta-analysis of placebo-controlled randomized trials

Rheumatology (Oxford). 2009 May;48(5):520-7. doi: 10.1093/rheumatology/ken470. Epub 2008 Dec 24.


Objective: Estimates of treatment effects reported in placebo-controlled randomized trials are less subject to bias than those estimates provided by other study designs. The objective of this meta-analysis was to estimate the analgesic effects of treatments for non-specific low back pain reported in placebo-controlled randomized trials.

Methods: Medline, Embase, Cinahl, PsychInfo and Cochrane Central Register of Controlled Trials databases were searched for eligible trials from earliest records to November 2006. Continuous pain outcomes were converted to a common 0-100 scale and pooled using a random effects model.

Results: A total of 76 trials reporting on 34 treatments were included. Fifty percent of the investigated treatments had statistically significant effects, but for most the effects were small or moderate: 47% had point estimates of effects of <10 points on the 100-point scale, 38% had point estimates from 10 to 20 points and 15% had point estimates of >20 points. Treatments reported to have large effects (>20 points) had been investigated only in a single trial.

Conclusions: This meta-analysis revealed that the analgesic effects of many treatments for non-specific low back pain are small and that they do not differ in populations with acute or chronic symptoms.

Publication types

  • Meta-Analysis
  • Review

MeSH terms

  • Acute Disease
  • Analgesia / methods*
  • Anti-Inflammatory Agents, Non-Steroidal / therapeutic use
  • Chronic Disease
  • Humans
  • Low Back Pain / therapy*
  • Manipulation, Spinal
  • Muscle Relaxants, Central / therapeutic use
  • Randomized Controlled Trials as Topic
  • Transcutaneous Electric Nerve Stimulation
  • Treatment Outcome


  • Anti-Inflammatory Agents, Non-Steroidal
  • Muscle Relaxants, Central