Placebo effects in low back pain

Placebo effects in low back pain: A systematic review and meta-analysis of the literature

van Lennep, Johan (Hans) Peter Alexander (Universiteit Leiden; Amsterdam UMC)
Trossèl, Faye (Amsterdam UMC)
Perez, Roberto Silvio Giovanni Maria (Amsterdam UMC)
Otten, René Hubert Joseph (Vrije Universiteit Amsterdam)
van Middendorp, Henriët (Universiteit Leiden; Amsterdam UMC)
Evers, A.W.M. (TU Delft Applied Ergonomics and Design; TU Delft HR Health; Universiteit Leiden; Leiden University Medical Center)
Szadek, Karolina Maria (Amsterdam UMC)

2021

Background and Objective: The current treatments of primary musculoskeletal low back pain (LBP) have a low to moderate efficacy, which might be improved by looking at the contribution of placebo effects. However, the size of true placebo effects in LBP is unknown. Therefore, a systematic review and meta-analysis were executed of randomized controlled trials investigating placebo effects in LBP. Databases and Data Treatment: The study protocol was registered in the international prospective register of systematic reviews Prospero (CRD42019148745). A literature search (in PubMed, Embase, The Cochrane Library, CINAHL and PsycINFO) up to 2021 February 16th yielded 2,423 studies. Two independent reviewers assessed eligibility and risk of bias. Results: Eighteen studies were eligible for the systematic review and 5 for the meta-analysis. Fourteen of the 18 studies were clinical treatment studies, and 4 were experimental studies specifically assessing placebo effects. The clinical treatment studies provided varying evidence for placebo effects in chronic LBP but insufficient evidence for acute and subacute LBP. Most experimental studies investigating chronic LBP revealed significant placebo effects. The meta-analysis of 5 treatment studies investigating chronic LBP depicted a significant moderate effect size of placebo for pain intensity (SMD = 0.57) and disability (SMD = 0.52). Conclusions: This review shows a significant contribution of placebo effects to chronic LBP symptom relief in clinical and experimental conditions. The meta-analysis revealed that placebo effects can influence chronic LBP intensity and disability. However, additional studies are required for more supporting evidence and evidence for placebo effects in acute or subacute LBP. Significance: This systematic review and meta-analysis provides evidence of true placebo effects in low back pain (LBP). It shows a significant contribution of placebo effects to chronic LBP symptom relief. The results highlight the importance of patient- and context-related factors in fostering treatment effects in this patient group. New studies could provide insight into the potential value of actively making use of placebo effects in clinical practice.

http://resolver.tudelft.nl/uuid:615a8d1d-621f-486f-964f-e014a63374b6

https://doi.org/10.1002/ejp.1811

1090-3801

EUROPEAN JOURNAL OF PAIN, 25 (9), 1876-1897

Institutional Repository

review

© 2021 Johan (Hans) Peter Alexander van Lennep, Faye Trossèl, Roberto Silvio Giovanni Maria Perez, René Hubert Joseph Otten, Henriët van Middendorp, A.W.M. Evers, Karolina Maria Szadek