Effect sizes of non-surgical treatments of non-specific low-back pain

Abstract

Numerous randomized trials have been published investigating the effectiveness of treatments for non-specific low-back pain (LBP) either by trials comparing interventions with a no-treatment group or comparing different interventions. In trials comparing two interventions, often no differences are found and it raises questions about the basic benefit of each treatment. To estimate the effect sizes of treatments for non-specific LBP compared to no-treatment comparison groups, we searched for randomized controlled trials from systematic reviews of treatment of non-specific LBP in the latest issue of the Cochrane Library, issue 2, 2005 and available databases until December 2005. Extracted data were effect sizes estimated as Standardized Mean Differences (SMD) and Relative Risk (RR) or data enabling calculation of effect sizes. For acute LBP, the effect size of non-steroidal anti-inflammatory drugs (NSAIDs) and manipulation were only modest (ES: 0.51 and 0.40, respectively) and there was no effect of exercise (ES: 0.07). For chronic LBP, acupuncture, behavioral therapy, exercise therapy, and NSAIDs had the largest effect sizes (SMD: 0.61, 0.57, and 0.52, and RR: 0.61, respectively), all with only a modest effect. Transcutaneous electric nerve stimulation and manipulation had small effect sizes (SMD: 0.22 and 0.35, respectively). As a conclusion, the effect of treatments for LBP is only small to moderate. Therefore, there is a dire need for developing more effective interventions.

Fig. 1

The pooled effect sizes for treatments for acute (at the top) and chronic low-back pain (at the bottom) for pain and function, short- and long-term follow-up, presented in a Forest plot

Fig. 2

The pooled effect sizes for included trials for treatments for chronic low-back pain, for pain presented in a Forest plot