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.
This meta-analysis assessed the effects of sham acupuncture in patients with primary dysmenorrhea and the factors contributing to these effects.
PubMed, Embase, Web of Science, and Cochrane CENTRAL databases were searched from inception up to August 20, 2022.
Randomized controlled trials (RCTs) using sham acupuncture as a control for female patients of reproductive age with primary dysmenorrhea were included.
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.
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.
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; 21(5): 455-463.

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

Red yeast rice (RYR), a natural lipid-lowering agent, is widely used in clinical practice. However, the existing meta-analyses concerning the safety of RYR preparations have yielded inconsistent results, and the credibility of the evidence has not been quantified.
This study was designed to evaluate the existing evidence and offer a comprehensive understanding of the associations between the use of RYR preparations and various adverse health outcomes.
Seven literature databases were searched from inception to May 5, 2023, using medical subject headings and free-text terms (e.g., "red yeast rice," "Xuezhikang," and "Zhibitai").
Meta-analyses that investigated and quantitatively estimated associations between the use of RYR preparations and adverse health outcomes were included in this study.
Two researchers independently extracted data using a standardized data collection table; any disagreements were resolved by consulting a third researcher. Based on the participant, intervention, comparator and outcome (PICO) framework in each eligible meta-analysis, a series of unique associations between the use of RYR preparations and adverse health outcomes were determined. The associations' effect estimates were re-evaluated using random-effect models.
Fifteen meta-analyses, comprising 186 (164 unique) randomized controlled trials, were identified. Based on A MeaSurement Tool to Assess Systematic Reviews version 2, 3 (20%) and 12 (80%) of these meta-analyses had low and critically low confidence, respectively. A total of 61 unique associations between the use of RYR preparations and adverse health outcomes were extracted from eligible meta-analyses. Based on the random-effect models, 10 (16.4%) associations indicated a significant protective effect of RYR preparations against adverse health outcomes, while 5 (8.2%) indicated an increased risk of adverse health outcomes related to uric acid, alanine transaminase and aspartate transaminase levels. The other 46 (75.4%) associations showed no significant difference between the use of RYR preparations and control treatments. Regarding the credibility of the evidence, 21 (34.4%), 34 (55.7%) and 6 (9.8%) associations showed moderate, low and very low credibility, respectively.
The evidence examined in this study suggests that RYR preparations are safe; however, the credibility of the evidence was not high. Further high-quality evidence is required. Please cite this article as: Ma ZY, Yang SP, Li Y, Xu TT, Yang YL, Yang HY, Li HB, Zhou LJ, Diao Y, Li SY. Associations between the use of red yeast rice preparations and adverse health outcomes: An umbrella review of meta-analyses of randomized controlled trials. J Integr Med. 2024; 22(2): 126-136.

Associations between the use of red yeast rice preparations and adverse health outcomes: An umbrella review of meta-analyses of randomized controlled trials.

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