Placebo response of sham acupuncture in patients with primary dysmenorrhea: A meta-analysis

Author: Chong-Yang Sun1, Zhi-Yi Xiong1, Cheng-Yi Sun1, Pei-Hong Ma1, Xiao-Yu Liu2, Chi-Yun Sun1, Ze-Yin Xin1, Bao-Yan Liu3, Cun-Zhi Liu4, S Y Yan5
Affiliation:
1 School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing 100029, China.
2 School of Acupuncture-Moxibustion and Tuina, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China.
3 Data Center of Traditional Chinese Medicine, China Academy of Chinese Medical Sciences, Beijing 100700, China.
4 School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing 100029, China; International Acupuncture and Moxibustion Innovation Institute, Beijing University of Chinese Medicine, Beijing 100029, China.
5 School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing 100029, China; International Acupuncture and Moxibustion Innovation Institute, Beijing University of Chinese Medicine, Beijing 100029, China. Electronic address: yanshiyan@bucm.edu.cn.
Conference/Journal: J Integr Med
Date published: 2023 Aug 11
Other: Special Notes: doi: 10.1016/j.joim.2023.08.005. , Word Count: 321


Background:
The placebo response of sham acupuncture in patients with primary dysmenorrhea is a substantial factor associated with analgesia. However, the magnitude of the placebo response is unclear.

Objective:
This meta-analysis assessed the effects of sham acupuncture in patients with primary dysmenorrhea and the factors contributing to these effects.

Search strategy:
PubMed, Embase, Web of Science, and Cochrane CENTRAL databases were searched from inception up to August 20, 2022.

Inclusion criteria:
Randomized controlled trials (RCTs) using sham acupuncture as a control for female patients of reproductive age with primary dysmenorrhea were included.

Data extraction and analysis:
Pain intensity, retrospective symptom scale, and health-related quality of life were outcome measures used in these trials. Placebo response was defined as the change in the outcome of interest from baseline to endpoint. We used standardized mean difference (SMD) to estimate the effect size of the placebo response.

Results:
Thirteen RCTs were included. The pooled placebo response size for pain intensity was the largest (SMD = -0.99; 95% confidence interval [CI], -1.31 to -0.68), followed by the retrospective symptom scale (Total frequency rating score: SMD = -0.20; 95% CI, -0.80 to -0.39. Average severity score: SMD = -0.35; 95% CI, -0.90 to -0.20) and physical component of SF-36 (SMD = 0.27; 95% CI, -0.17 to 0.72). Studies using blunt-tip needles, single-center trials, studies with a low risk of bias, studies in which patients had a longer disease course, studies in which clinicians had < 5 years of experience, and trials conducted outside Asia were more likely to have a lower placebo response.

Conclusion:
Strong placebo response and some relative factors were found in patients with primary dysmenorrhea. PROSPERO registration number: CRD42022304215. Please cite this article as: Sun CY, Xiong ZY, Sun CY, Ma PH, Liu XY, Sun CY, Xin ZY, Liu BY, Liu CZ, Yan SY. Placebo response of sham acupuncture in patients with primary dysmenorrhea: a meta-analysis. J Integr Med. 2023; Epub ahead of print.

Keywords: Meta-analysis; Pain; Placebo response; Primary dysmenorrhea; Sham acupuncture.

PMID: 37620224 DOI: 10.1016/j.joim.2023.08.005

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