Abstract
ABSTRACT: Little is known about the effectiveness of placebo interventions in patients with nonspecific low back pain (LBP). This systematic review assessed the magnitude of the effects of placebo interventions as compared to no intervention in randomized controlled trials (RCTs) including patients with LBP. Embase, MEDLINE (Ovid), and Cochrane CENTRAL databases were searched from inception to December 5, 2019. Randomized controlled trials comparing placebo intervention vs no intervention in adult patients with nonspecific LBP were included. Pain intensity, physical functioning, and health-related quality of life measured at short-term, medium-term, and long-term follow-up were the outcomes of this review. Twenty-one randomized controlled trials were included; one concerning acute LBP and one subacute LBP, whereas 19 studies reported on chronic LBP. In chronic LBP, placebo interventions were more effective than no intervention at short-term follow-up for pain intensity (standardized mean difference = -0.37, 95% confidence interval [CI] = -0.55 to -0.18, moderate-quality evidence), physical functioning (standardized mean difference -0.19, 95% CI = -0.39-0.01, moderate-quality evidence), and physical quality of life (mean difference = -2.71, 95% CI = -4.71-0.71, high-quality evidence), respectively. These effects were not significant at medium-term follow-up, and no data were available at long-term follow-up. These results show placebo interventions are more effective than no intervention at short-term follow-up in patients with chronic LBP. However, the magnitude of the effects is probably not clinically relevant (approximately 8 points on a 0-100 pain scale). Future research should identify effect modifiers and causal mechanisms explaining the short-term effects of placebo interventions in patients with chronic LBP.
| Original language | English |
|---|---|
| Pages (from-to) | 2792-2804 |
| Number of pages | 13 |
| Journal | Pain |
| Volume | 162 |
| Issue number | 12 |
| Early online date | 24 Mar 2021 |
| DOIs | |
| Publication status | Published - Dec 2021 |
Bibliographical note
Publisher Copyright:Copyright © 2021 International Association for the Study of Pain.
Funding
The authors would like to thank Wichor M. Bramer for his help in developing the database search syntaxes for this systematic review. M. Schreijenberg, A. Chiarotto, and B.W. Koes made substantial intellectual contributions to the development of the original study protocol of this systematic review. R.H.W. Strijkers and M. Schreijenberg performed the data selection, data extraction, and risk of bias assessment. R.H.W. Strijkers conducted the analyses under supervision of H. Gerger and A. Chiarotto. R.H.W. Strijkers, A. Chiarotto, and H. Gerger interpreted the results. R.H.W. Strijkers and M. Schreijenberg drafted the manuscript, which was revised by A. Chiarotto, B.W. Koes, and H. Gerger. All authors have read and approved the final manuscript.
