BACKGROUND: Acupuncture has shown potential therapeutic benefits for individuals with simple obesity. However, some researchers argue that some of the effectiveness of acupuncture may be due to the placebo response. OBJECTIVE: To understand the placebo response of acupuncture treatment in simple obesity, a systematic review and meta-analysis was designed based on the comparison between sham acupuncture before and after treatment. SEARCH STRATEGY: Eight databases (PubMed, Web of Science, Cochrane Library, Embase, China National Knowledge Infrastructure, Wanfang Database, China Biology Medicine Database, and Chinese Scientific Journals Database) were searched from inception to August 1, 2023. The MeSH search terms comprised obesity and acupuncture. INCLUSION CRITERIA: Randomized controlled trials (RCTs) using sham or placebo acupuncture as a control in treating obesity were enrolled. DATA EXTRACTION AND ANALYSIS: Two researchers independently extracted data, and the results were cross-checked after completion. Each RCT's detailed sham/placebo acupuncture treatment protocol was assessed according to the SHam Acupuncture REporting guidelines. The revised Cochrane risk-of-bias tool for randomized trials and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system were used to determine the risk of bias and quality of evidence, respectively. Body mass index (BMI) was defined as the primary outcome. Anthropometric parameters and laboratory test parameters related to obesity were defined as secondary outcomes. We used standardized mean difference (SMD) with 95% confidence interval (CI) to calculate treatment effects of outcomes. RESULTS: Fifteen RCTs with a total of 1250 patients were included. The BMI significantly decreased after treatment in the sham acupuncture group compared to baseline (SMD 0.37, 95% CI 0.09-0.66; I² = 81%, random model; P < 0.01). Treatment duration (P = 0.02) and other interventions significantly impacted the placebo response rate (P = 0.00). CONCLUSION The placebo response of sham acupuncture was strong in the RCTs for simple obesity, and the effect sizes differed between various outcomes. The treatment duration and other interventions emerged as potential influencing factors for the placebo response of sham acupuncture. Please cite this article as: Liu KJ, Jiao RM, Ji J, Yao WW, Han CR, Zhao XY, Zhao JJ. Placebo response in sham acupuncture therapy trials for simple obesity: a systematic review and meta-analysis. J Integr Med. 2025; 23(3): 264-273.
Humans ; Acupuncture Therapy/methods* ; Obesity/therapy* ; Placebo Effect ; Placebos ; Randomized Controlled Trials as Topic

BACKGROUND: The use of inserted sham acupuncture as a placebo in randomized controlled trials (RCTs) is controversial, because it may produce specific effects that cause an underestimation of the effect of acupuncture treatment. OBJECTIVE: This systematic survey investigates the magnitude of insert-specific effects of sham acupuncture and whether they affect the estimation of acupuncture treatment effects. SEARCH STRATEGY: PubMed, Embase and Cochrane Central Register of Controlled Trials were searched to identify acupuncture RCTs from their inception until December 2022. INCLUSION CRITERIA: RCTs that evaluated the effects of acupuncture compared to sham acupuncture and no treatment. DATA EXTRACTION AND ANALYSIS: The total effect measured for an acupuncture treatment group in RCTs were divided into three components, including the natural history and/or regression to the mean effect (controlled for no-treatment group), the placebo effect, and the specific effect of acupuncture. The first two constituted the contextual effect of acupuncture, which is mimicked by a sham acupuncture treatment group. The proportion of acupuncture total effect size was considered to be 1. The proportion of natural history and/or regression to the mean effect (PNE) and proportional contextual effect (PCE) of included RCTs were pooled using meta-analyses with a random-effect model. The proportion of acupuncture placebo effect was the difference between PCE and PNE in RCTs with non-inserted sham acupuncture. The proportion of insert-specific effect of sham acupuncture (PIES) was obtained by subtracting the proportion of acupuncture placebo effect and PNE from PCE in RCTs with inserted sham acupuncture. The impact of PIES on the estimation of acupuncture's treatment effect was evaluated by quantifying the percentage of RCTs that the effect of outcome changed from no statistical difference to statistical difference after removing PIES in the included studies, and the impact of PIES was externally validated in other acupuncture RCTs with an inserted sham acupuncture group that were not used to calculate PIES. RESULTS: This analysis included 32 studies with 5492 patients. The overall PNE was 0.335 (95% confidence interval [CI], 0.255-0.415) and the PCE of acupuncture was 0.639 (95% CI, 0.567-0.710) of acupuncture's total effect. The proportional contribution of the placebo effect to acupuncture's total effect was 0.191, and the PIES was 0.189. When we modeled the exclusion of the insert-specific effect of sham acupuncture, the acupuncture treatment effect changed from no difference to a significant difference in 45.45% of the included RCTs, and in 40.91% of the external validated RCTs. CONCLUSION The insert-specific effect of sham acupuncture in RCTs represents 18.90% of acupuncture's total effect and significantly affects the evaluation of the acupuncture treatment effect. More than 40% of RCTs that used inserted sham acupuncture would draw different conclusions if the PIES had been controlled for. Considering the impact of the insert-specific effect of sham acupuncture, caution should be taken when using inserted sham acupuncture placebos in RCTs. Please cite this article as: Luo XC, Liu JL, Yao MH, Chen YM, Fan AY, Liang FR, Zhao JP, Zhao L, Zhou X, Zhong XY, Yang JH, Li B, Zhang Y, Sun X, Li L. Specific effect of inserted sham acupuncture and its impact on the estimation of acupuncture treatment effect in randomized controlled trials: A systematic survey. J Integr Med. 2025; 23(6):630-640.
Acupuncture Therapy/methods* ; Humans ; Randomized Controlled Trials as Topic ; Placebo Effect ; Placebos ; Treatment Outcome

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; 21(5): 455-463.
Female ; Humans ; Dysmenorrhea/therapy* ; Acupuncture Therapy ; Pain Management ; Needles ; Placebo Effect

In recent years, some large rigorous acupuncture randomized controlled trials (RCTs) frequently draw the conclusion that the therapeutic effects of acupuncture is equivalent to placebo effect, which has aroused wide attention and controversy. Thus, some studies attempted to assess the adequacy of acupuncture regimen in clinical trials. In this study, the concept of acupuncture regimen adequacy in clinical trials is clarified and the research status and limitations are summarized. Moreover, the suggestions in the future researches are proposed in association with clinical practice characteristics of acupuncture, i.e. classifying assessment according to different types of acupuncture; conducting the assessment according to the treatment characteristics of different types of acupuncture; assessing the maturity of acupuncture regimens; evaluating the rationality of the control group according to the purpose of the study; and focusing on domains evaluation.
Acupuncture Therapy ; Clinical Trials as Topic ; Placebo Effect

BACKGROUND: Menopausal symptoms have remarkable negative effects on women's quality of life, justifying the need to assess various therapeutic options. This research aimed to determine the effectiveness of Vitex agnus-castus extracts in alleviating menopausal symptoms in comparison with that of placebo. METHODS: This study was a randomized controlled double-blind clinical trial with a study group of 52 women referred to a clinic in Kermanshah in 2017. The participants were randomly divided into two groups: Vitex group (26 subjects) and placebo group (26 subjects). Menopausal symptoms were assessed using the Greene Scale before and 8 weeks after the intervention. RESULTS: After the intervention, the mean scores for total menopausal disorder, anxiety, and vasomotor dysfunction were significantly lower in the Vitex group than in the placebo group (P<0.05). The mean scores of the variables of somatic complications, depression, and sexual dysfunction did not show significant differences between the Vitex and placebo groups (P>0.05). CONCLUSION: Administration of Vitex agnus-castus extracts as a phytoestrogenic medicine can alleviate menopausal symptoms in women.
Anxiety Disorders ; Depression ; Double-Blind Method ; Female ; Humans ; Menopause ; Phytoestrogens ; Placebo Effect ; Quality of Life ; Vitex

PURPOSE: Inhaled corticosteroids (ICSs) are often considered an empirical therapy in the management of patients with cough. However, ICS responsiveness is difficult to interpret in daily clinical practice, as the improvements may include placebo effects or self-remission. We aimed to evaluate ICS and placebo treatment effects in adult patients with cough. METHODS: Electronic databases were searched for studies published until June 2018, without language restriction. Randomized controlled trials reporting the effects of ICSs compared with placebo in adult patients with cough were included. Random effects meta-analyses were conducted to estimate the treatment effects. Therapeutic gain was calculated by subtracting the percentage change from baseline in the cough score in the ICS treatment group from that in the placebo treatment group. RESULTS: A total of 9 studies were identified and 8 studies measuring cough severity outcomes were included for meta-analyses. Therapeutic gain from ICSs ranged from −5.0% to +94.6% across the studies included; however, it did not exceed +22%, except for an outlier reporting very high therapeutic gains (+45.6% to +94.6%, depending on outcomes). Overall ICS treatment effects in cough severity outcomes were small-to-moderate (standardized mean difference [SMD], −0.38; 95% confidence interval [CI], −0.54, −0.23), which were comparable between subacute and chronic coughs. However, pooled placebo treatment effects were very large in subacute cough (SMD, −2.58; 95% CI, −3.03, −2.1), and modest but significant in chronic cough (SMD, −0.46; 95% CI, −0.72, −0.21). CONCLUSIONS: Overall therapeutic gain from ICSs is small-to-moderate. However, placebo treatment effects of ICS are large in subacute cough, and modest but still significant in chronic cough. These findings indicate the need for careful interpretation of ICS responsiveness in the management of cough patients in the clinic, and also for rigorous patient selection to identify ICS-responders.
Adrenal Cortex Hormones ; Adult ; Cough ; Humans ; Overall ; Patient Selection ; Placebo Effect ; Steroids

OBJECTIVETo investigate the influence of the depth of skin press in blunt tip placebo acupuncture needles on patient blinding and its relationship to needle diameter.

METHODSForty healthy volunteers were enrolled as subjects for patient blinding. Four acupuncturists applied the following needles randomly at three points in each forearm: 0.18 mm and 0.25 mm diameter penetrating needles inserted to a depth of 5 mm, and 0.18 mm and 0.25 mm diameter skin-touch needles depressing the skin at the acupoint to a depth of 1 mm and 2 mm from the skin surface. The subjects reported their guesses at the nature of needles they received, and rated needle pain and de qi. A blinding index was calculated to define the success of blinding for subjects.

RESULTSThe blinding status of subjects for 1 mm press needles of 0.18 mm diameter was "random guess", but "unblinded" for 1 mm press needles of 0.25 mm diameter. For 2 mm press needles of both diameters, the blinding status was "opposite guess" and the blinding status for penetrating needles of both diameters was "unblinded." The percentages of "felt pain" with 2 mm press needles of both diameters were similar to that with penetrating needles, but those were not similar for 1 mm press needles. The frequency of de qi occurrence with 2 mm press needles of 0.18 mm diameter was similar to that of penetrating needles of both diameters.

CONCLUSIONPlacebo needles of 2 mm press made more subjects guess that the needles penetrated the skin than 1 mm press needles. The use of small diameter needles increased patient blinding.

Acupuncture Points ; Acupuncture Therapy ; instrumentation ; methods ; Adult ; Female ; Healthy Volunteers ; Humans ; Male ; Middle Aged ; Needles ; statistics & numerical data ; Placebo Effect ; Sensation ; Young Adult

The application of placebo acupuncture in randomized controlled trials in the past 10 years (2004-2014) in foreign countries was systematically reviewed to summarize the design of placebo acupuncture; according to category of diseases, advantages and disadvantages were analyzed to explore an ideal placebo acupuncture set. By retrieval in PubMed, EMBASE and OVID databases, the clinical study literature which met the inclusion criteria was searched, and the category of diseases, design of placebo acupuncture and clinical efficacy were analyzed. Totally 29 articles were included. The pain was the leading disease in category of diseases; the most commonly used application of placebo acupuncture design was telescopiform sliding blunt needle, accounting for 45. 16%; the treatment locations were non-acupoints mostly; in the needling depth, approximately 60. 00% selected non-penetrating needling and 26. 67% selected superficial needling; 28 articles indicated that acupuncture and placebo acupuncture had clinical effects, accounting for 96. 55%; 37. 93% of articles indicated acupuncture was superior to placebo acupuncture and 37. 93% of articles indicated acupuncture was not superior to placebo acupuncture. It is concluded that the design of placebo acupuncture should consider multiple factors, including main symptoms, operability, security, blinding and specific effects, and the objective indices should be selected for outcome evaluation.
Acupuncture Therapy ; instrumentation ; methods ; standards ; Humans ; Internationality ; Needles ; Placebo Effect ; Randomized Controlled Trials as Topic ; standards

Pharmacotherapy has been constantly chosen by the clinician among the available treatment options for tinnitus. Medications that have been prescribed off-label to treat tinnitus can be grouped into several categories: benzodiazepines, antidepressants, anticonvulsants, N-methyl-D-aspartate (NMDA) receptor antagonists, dopamine receptor modulators, muscle relaxants, and others. In this article, a wide variety of compounds once used in the treatment of tinnitus and evidenced by clinical trials are reviewed with respect to the mechanisms of action and the drug efficacy. Only a few of the various pharmacological interventions investigated have some beneficial effects against tinnitus: clonazepam, acamprosate, neramexan, and sulpiride. Sertraline and pramipexole were effective in subgroups of patients with psychiatric symptoms or presbycusis. However, no agents have been identified to provide a reproducible long-term reduction of tinnitus in excess of placebo effects. In rodent tinnitus models, L-baclofen, memantine, and KCNQ2/3 channel activators have been demonstrated to reduce tinnitus development. Limitation of the use of an effective high dosage during a longer treatment duration due to dose-dependent side effects of the centrally acting drugs may influence the results in clinical studies. More effective and safer innovative agents should be developed based on the further understanding of tinnitus neural mechanisms and valid animal models, and should be supported by improved clinical trial methodology. The management of tinnitus patients through a tailored treatment approach depending on the detailed classification of tinnitus subtypes will also lead to better treatment outcomes.
Anticonvulsants ; Antidepressive Agents ; Benzodiazepines ; Classification ; Clonazepam ; Dopamine Agonists ; Dopamine Antagonists ; Drug Therapy ; Humans ; Memantine ; Models, Animal ; N-Methylaspartate ; Placebo Effect ; Presbycusis ; Rodentia ; Sertraline ; Sulpiride ; Tinnitus*

The effect of hydroxychloroquine (HCQ) on dry eye has not been fully determined. This study aimed to compare the 12-week efficacy of HCQ medication with that of a placebo in the management of dry eye in primary Sjögren's syndrome (pSS). A double-blind, randomized control study was conducted in 39 pSS subjects from May 2011 through August 2013. pSS was diagnosed based on the classification criteria of the American-European Consensus Group. Subjects received 300 mg of HCQ or placebo once daily for 12 weeks and were evaluated at baseline, 6, and 12 weeks, with a re-visit at 16 weeks after drug discontinuance. The fluorescein staining score, Schirmer test score, tear film break-up time (TBUT), and ocular surface disease index (OSDI) were measured, and tears and blood were collected for ESR, IL-6, IL-17, B-cell activating factor (BAFF), and Th17 cell analysis. Color testing was performed and the fundus was examined to monitor HCQ complications. Twenty-six subjects completed the follow-up. The fluorescein staining score and Schirmer test score did not differ significantly. The OSDI improved with medication in the HCQ group but was not significantly different between the groups. TBUT, serum IL-6, ESR, serum and tear BAFF, and the proportion of Th17 cells did not change in either group. HCQ at 300 mg daily for 12 weeks has no apparent clinical benefit for dry eye and systemic inflammation in pSS (ClinicalTrials.gov. NCT01601028).
Aged ; B-Cell Activating Factor/analysis/blood ; Blood Sedimentation ; Double-Blind Method ; Drug Administration Schedule ; Dry Eye Syndromes/complications/*drug therapy ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Hydroxychloroquine/*therapeutic use ; Interleukin-16/analysis/blood ; Interleukin-17/analysis/blood ; Male ; Middle Aged ; Placebo Effect ; Prospective Studies ; Sjogren's Syndrome/*complications/diagnosis ; Th17 Cells/cytology/immunology ; Treatment Outcome