Open label placebo for chronic low back pain: a systematic review and meta-analysis of randomized controlled trials.

Aim: To assess the therapeutic potential of Open-Label Placebo (OLP) for chronic low back pain (CLBP).

Materials & methods: A systematic literature search was conducted on 12 September 2024. Data extraction focused on follow-up and change-from-baseline data of the placebo or control groups. The effect sizes were calculated using the inverse variance statistical method.

Results: A meta-analysis of four articles involving 171 OLP patients and 161 controls demonstrated a modest reduction in pain on the numerical rating scale (Mean difference = -0.62; 95% confidence interval: -1.09 to -0.14; p = 0.01; I² = 31%). However, according to GRADE, the certainty of evidence for this finding is very low due to methodological limitations of the included studies and potential biases. These findings, even if small, suggest potential benefits of OLP for pain reduction, with clinical relevance of the effect size being important depending on the clinical context and the patient's perspective.

Conclusions: OLP demonstrated a reduction in pain, with a slightly greater improvement observed during shorter intervention periods. However, the certainty of this evidence remains very low, indicating that these findings should be interpreted cautiously. Future clinical trials are needed to further explore the potential and limitations of this intervention.

Protocol registration: www.crd.york.ac.uk/prospero identifier is CRD42024568302.