Placebo interventions for all clinical conditions

A narrative review of the placebo effect: historical roots, current applications, and emerging insights

PURPOSE

Placebo is a term to define physiologically inactive compounds used in treatment that causes physical and emotional changes. The placebo effect, driven by expectation and conditioning, plays a significant role in various conditions like pain, depression, and Parkinson's disease, while the nocebo effect can hinder treatment outcomes. Understanding mechanisms such as neuromodulation and genetics has gained importance in modern medicine. This review aims to explore the clinical relevance of placebo responses, particularly in neuropsychiatric disorders, and their potential in personalized medicine. By integrating placebo research into healthcare, it highlights opportunities to enhance treatment efficacy, improve patient well-being, and reduce reliance on pharmacological interventions.

METHODS

A comprehensive literature search was conducted in PubMed, Scopus, and Google Scholar databases. Recent studies were reviewed to evaluate placebo effects, and the variability of the placebo response in neuropsychiatric disorders was summarized.

RESULTS

Placebo effects significantly impact treatment outcomes across various conditions, including Parkinson's disease, depression, pain syndromes, and epilepsy. The mechanisms involve neurobiological and psychological factors, with evidence suggesting that placebo interventions can modulate neurotransmitter activity and improve patient well-being.

CONCLUSION

Integrating placebo research into clinical practice may enhance treatment outcomes, reduce drug dependency, and support personalized medicine by tailoring interventions to individual placebo responsiveness. Understanding placebo and nocebo mechanisms can optimize therapeutic strategies while minimizing unnecessary pharmacological treatments.

A systematic qualitative review of ethical issues in open label placebo in published research

Open-label placebos (OLPs), which are transparently administered inert treatments, have gained increasing attention in the research community. They have the potential to harness placebo effects without deceiving the patient. The purpose of this study was to examine and synthesize prior research discussing ethical issues in OLPs. A systematic qualitative literature review was conducted (last search on January 2023) across multiple databases (e.g., MEDLINE, Embase, PsycInfo) using keywords related to OLPs. Publications were screened and assessed for eligibility. Seventeen articles explicitly addressing OLP ethics were included. Data were extracted and thematically analyzed following established qualitative content analysis procedures. 37 distinct ethical issues were identified, grouped into five overarching themes: (1) Sociocultural and Contextual Factors, (2) Implementation and Logistics, (3) Informed Consent, (4) Patient Health Behavior and Dynamics, and (5) Therapeutic Relationship. Frequently mentioned concerns focused on uncertainty of OLP efficacy, the need for further research, and complexities of dose-extending OLPs. The effective integration of OLPs into healthcare necessitates thoughtful consideration and responsible communication. This analysis shows that demonstrating the efficacy of OLPs becomes pivotal for their widespread adoption, underscoring the necessity for additional research to validate their effectiveness. This review was pre-registered on January 26th, 2023, in the Open Science Framework Registry under the identifier: DOI https://doi.org/10.17605/OSF.IO/R6NKG .

"The Dark Side of Musculoskeletal Care": Why Do Ineffective Techniques Seem to Work? A Comprehensive Review of Complementary and Alternative Therapies

The increasing interest in complementary and alternative medicines (CAMs) for musculoskeletal care has sparked significant debate, particularly regarding their biological plausibility and clinical effectiveness. This comprehensive review critically examines the use of two of the most widely utilized CAMs-osteopathy and chiropractic care-over the past 25 years, focusing on their biological plausibility, clinical effectiveness, and potential mechanisms of action. Our analysis of current research and clinical studies reveals that osteopathy and chiropractic are based on concepts such as "somatic dysfunction" and "vertebral subluxation", which lack robust empirical validation. While these therapies are often presented as credible treatment options, studies evaluating their effectiveness frequently exhibit serious methodological flaws, providing insufficient empirical support for their recommendation as first-line treatments for musculoskeletal conditions. The effects and mechanisms underlying osteopathy and chiropractic remain poorly understood. However, placebo responses-mediated by the interaction of contextual, psychological, and non-specific factors-appear to play a significant role in observed outcomes. The integration of therapies with limited biological plausibility, whose effects may primarily rely on placebo effects, into healthcare systems raises important ethical dilemmas. This review highlights the need for rigorous adherence to scientific principles and calls for a more comprehensive investigation into biobehavioral, contextual, and psychosocial factors that interact with the specific effects of these interventions. Such efforts are essential to advancing our understanding of CAMs, enhancing clinical decision-making, promoting ethical practices, and guiding future research aimed at improving patient care in musculoskeletal disorders.

Treatment for women with postpartum iron deficiency anaemia

RATIONALE

Postpartum iron deficiency anaemia is caused by antenatal iron deficiency or excessive blood loss at delivery and might affect up to 50% of labouring women in low- and middle-income countries. Effective and safe treatment during early motherhood is important for maternal well-being and newborn care. Treatment options include oral iron supplementation, intravenous iron, erythropoietin, and red blood cell transfusion.

OBJECTIVES

To assess the benefits and harms of the available treatment modalities for women with postpartum iron deficiency anaemia. These include intravenous iron, oral iron supplementation, red blood cell transfusion, and erythropoietin.

SEARCH METHODS

A Cochrane Information Specialist searched for all published, unpublished, and ongoing trials, without language or publication status restrictions. We searched databases including CENTRAL, MEDLINE, Embase, CINAHL, LILACS, WHO ICTRP, and ClinicalTrials.gov, together with reference checking, citation searching, and contact with study authors to identify eligible studies. We applied date limits to retrieve new records since the last search on 9 April 2015 until 11 April 2024.

ELIGIBILITY CRITERIA

We included published, unpublished, and ongoing randomised controlled trials (RCTs) that compared treatments for postpartum iron deficiency anaemia with placebo, no treatment, or alternative treatments. Cluster-randomised trials were eligible for inclusion. We included RCTs regardless of blinding. Participants were women with postpartum haemoglobin ≤ 12 g/dL, treated within six weeks after childbirth. We excluded non-randomised, quasi-randomised, and cross-over trials.

OUTCOMES

The critical outcomes of this review were maternal mortality and fatigue. The important outcomes included persistent anaemia symptoms, persistent postpartum anaemia, psychological well-being, infections, compliance with treatment, breastfeeding, length of hospital stay, serious adverse events, anaphylaxis or evidence of hypersensitivity, flushing/Fishbane reaction, injection discomfort/reaction, constipation, gastrointestinal pain, number of red blood cell transfusions, and haemoglobin levels.

RISK OF BIAS

We assessed risk of bias in the included studies using the Cochrane RoB 1 tool.

SYNTHESIS METHODS

Two review authors independently performed study screening, risk of bias assessment, and data extraction. We contacted trial authors for supplementary data when necessary. We screened all trials for trustworthiness and scientific integrity using the Cochrane Trustworthiness Screening Tool. We conducted meta-analyses using a fixed-effect model whenever feasible to synthesise outcomes. In cases where data were not suitable for meta-analysis, we provided a narrative summary of important findings. We evaluated the overall certainty of the evidence using GRADE.

INCLUDED STUDIES

We included 33 RCTs with a total of 4558 postpartum women. Most trials were at high risk of bias for several risk of bias domains.

SYNTHESIS OF RESULTS

Most of the evidence was of low or very low certainty. Imprecision due to few events and risk of bias due to lack of blinding were the most important factors. Intravenous iron versus oral iron supplementation The evidence is very uncertain about the effect of intravenous iron on mortality (risk ratio (RR) 2.95, 95% confidence interval (CI) 0.12 to 71.96; P = 0.51; I² = not applicable; 3 RCTs; 1 event; 572 women; very low-certainty evidence). One woman died of cardiomyopathy, and another developed arrhythmia, both in the groups treated with intravenous iron. Intravenous iron probably results in a slight reduction in fatigue within 8 to 28 days (standardised mean difference -0.25, 95% CI -0.42 to -0.07; P = 0.006; I² = 47%; 2 RCTs; 515 women; moderate-certainty evidence). Breastfeeding was not reported. Oral iron probably increases the risk of constipation compared to intravenous iron (RR 0.12, 95% CI 0.06 to 0.21; P < 0.001; I² = 0%; 10 RCTs; 1798 women; moderate-certainty evidence). The evidence is very uncertain about the effect of intravenous iron on anaphylaxis or hypersensitivity (RR 2.77, 95% CI 0.31 to 24.86; P = 0.36; I² = 0%; 12 RCTs; 2195 women; very low-certainty evidence). Three women treated with intravenous iron experienced anaphylaxis or hypersensitivity. The trials that reported on haemoglobin at 8 to 28 days were too heterogeneous to pool. However, 5 of 6 RCTs favoured intravenous iron, with mean changes in haemoglobin ranging from 0.73 to 2.10 g/dL (low-certainty evidence). Red blood cell transfusion versus intravenous iron No women died in the only trial that reported on mortality (1 RCT; 7 women; very low-certainty evidence). The evidence is very uncertain about the effect of red blood cell transfusion on fatigue at 8 to 28 days (mean difference (MD) 1.20, 95% CI -2.41 to 4.81; P = 0.51; I² = not applicable; 1 RCT; 13 women; very low-certainty evidence) and breastfeeding more than six weeks postpartum (RR 0.43, 95% CI 0.12 to 1.57; P = 0.20; I² = not applicable; 1 RCT; 13 women; very low-certainty evidence). Constipation and anaphylaxis were not reported. Red blood cell transfusion may result in little to no difference in haemoglobin within 8 to 28 days (MD -1.00, 95% CI -2.02 to 0.02; P = 0.05; I² = not applicable; 1 RCT; 12 women; low-certainty evidence). Intravenous iron and oral iron supplementation versus oral iron supplementation Mortality and breastfeeding were not reported. One trial reported a greater improvement in fatigue in the intravenous and oral iron group, but the effect size could not be calculated (1 RCT; 128 women; very low-certainty evidence). Intravenous iron and oral iron may result in a reduction in constipation compared to oral iron alone (RR 0.21, 95% CI 0.07 to 0.69; P = 0.01; I² = not applicable; 1 RCT; 128 women; low-certainty evidence). There were no anaphylaxis or hypersensitivity events in the trials (2 RCTs; 168 women; very low-certainty evidence). Intravenous iron and oral iron may result in little to no difference in haemoglobin (g/dL) at 8 to 28 days (MD 0.00, 95% CI -0.48 to 0.48; P = 1.00; I² = not applicable; 1 RCT; 60 women; low-certainty evidence). Red blood cell transfusion versus no transfusion Mortality, fatigue at day 8 to 28, constipation, anaphylaxis, and haemoglobin were not reported. Red blood cell transfusion may result in little to no difference in breastfeeding more than six weeks postpartum (RR 0.91, 95% CI 0.78 to 1.07; P = 0.24; I² = not applicable; 1 RCT; 297 women; low-certainty evidence). Oral iron supplementation versus placebo or no treatment Mortality, fatigue, breastfeeding, constipation, anaphylaxis, and haemoglobin were not reported. Two trials reported on gastrointestinal symptoms, but did not report results by study arm.

AUTHORS' CONCLUSIONS

Intravenous iron probably reduces fatigue slightly in the early postpartum weeks (8 to 28 days) compared to oral iron tablets, but probably results in little to no difference after four weeks. It is very uncertain if intravenous iron has an effect on mortality and anaphylaxis/hypersensitivity. Breastfeeding was not reported. Intravenous iron may increase haemoglobin slightly more than iron tablets, but the data were too heterogeneous to pool. However, changes in haemoglobin levels are a surrogate outcome, and treatment decisions should preferentially be based on patient-relevant outcomes. Iron tablets probably result in a large increase in constipation compared to intravenous iron. The effect of red blood cell transfusion compared to intravenous iron on mortality, fatigue, and breastfeeding is very uncertain. No studies reported on constipation or anaphylaxis/hypersensitivity. Red blood cell transfusion may result in little to no difference in haemoglobin at 8 to 28 days. The effect of intravenous iron and oral iron supplementation on mortality, fatigue, breastfeeding, and anaphylaxis/hypersensitivity is very uncertain or unreported. Intravenous iron and oral iron may result in a reduction in constipation compared to oral iron alone, and in little to no difference in haemoglobin. The effect of red blood cell transfusion compared to non-transfusion on mortality, fatigue, constipation, anaphylaxis/hypersensitivity, and haemoglobin is unreported. Red blood cell transfusion may result in little to no difference in breastfeeding. The effect of oral iron supplementation on mortality, fatigue, breastfeeding, constipation, anaphylaxis/hypersensitivity, and haemoglobin is unreported.

FUNDING

This Cochrane review had no dedicated funding.

REGISTRATION

Protocol and previous versions are available: Protocol (2013) [DOI: 10.1002/14651858.CD010861] Original review (2004) [DOI: 10.1002/14651858.CD004222.pub2] Review update (2015) [DOI: 10.1002/14651858.CD010861.pub2].

Comparison of the effectiveness of botulinum toxin, dry needling, pharmacological treatment, and manual therapy for bruxism-induced myalgia: a prospective randomized study

Bruxism is a significant phenomenon that should not be underestimated, given its prevalence and consequences. The major symptoms associated with bruxism include myalgia, decreased quality of life, and limited mandibular movements. This study aimed to evaluate and compare the effectiveness of four treatment methods for managing bruxism-related symptoms: botulinum toxin (BoNT-A), dry needling (DN), pharmacological therapy (PT), and manual therapy (MT). Eighty patients with bruxism (44 female, 36 male) were randomly assigned to four groups of 20 patients each. All therapies were administered by the same maxillofacial surgeon. Measurements were recorded at baseline (pre-treatment) and at 2, 4 and 12 weeks post-treatment. The metrics assessed included the visual analog scale (VAS) for pain, maximum painless mouth opening (MMO), and the Oral Health Impact Profile-14 (OHIP-14) questionnaire. Statistical analysis was performed using a mixed-design repeated measures two-way analysis of variance (ANOVA) to compare changes within and among the groups over time. Tukey's multiple comparison test was applied for further analysis. The results indicated that both objective and subjective clinical outcomes were similar across all treatment groups. Considering their competitive efficiency, non-invasiveness or minimal invasiveness, and cost-effectiveness, DN, MT and PT appear to be promising alternatives for managing bruxism and its symptoms, especially in the early stages. ClinicalTrials ID: NCT06583551.

Prayers for Sickness: What do people pray for and how do they deal with unanswered prayer?

Background

This paper focuses upon prayer for sickness. What do individuals suffering from illness, their families and the wider community pray for? How do they deal with unanswered prayer? Do they pray for cure, to guide medical professionals or to cope with their sickness? What rationalisations do they proffer for unanswered prayer?

Methods

Based on a critical literature review and deploying secondary data from the Twenty First Century Evangelical research programme, the data suggest that prayers for guiding medical professionals and coping are more common than for cure, at least in Global North countries such as the UK and US. But why do those who believe in miracles not ask God for divine healing? Furthermore, unanswered prayer can conflict with Christian views of God as omnipotent and all loving.

Results

Respondents use a number of theodical rationalisations to resolve this conflict.

Conclusions

The results are discussed in relation to cognitive dissonance theory, learned helplessness, the need to conserve a relationship with the Divine, and desire to manage risk of disappointment and reduce consequent emotional pain.

[The effect of electromagnetic fields on tendinopathies : Study on the effect analysis of a singular application of high-energy pulsed electromagnetic fields]

OBJECTIVE

Tendinopathies are diseases that often entail long-term treatment consisting of analgesics, physiotherapy, orthotics, and sparing. The aim of this study was to investigate the effect of a single application of a high-energy PEMF (pulsed electromagnetic field) on pain perception and blood born inflammation parameters.

METHODS

34 patients were randomly assigned to a verum group (10 min PEMF, 0,78 T) or a placebo group (10 min sham condition). Prior to and up to one week after the patient blinded treatment (t1-t5), local pain state was assessed by means of algometry as pain pressure threshold (PPT). Accordingly, heat-shock protein 70 (HSP70) levels were analysed. Statistical analyses included 2‑way ANOVA (2 × 5). The clinical trial was registered (DRKS00031321).

RESULTS

After randomization and drop-out (verum n = 17, placebo n = 13) baseline-analyses did not reveal significant between-group differences for PPT (p = 0,096), for HSP70 (p = 0,524), or any other sample characteristics (p > 0,05). Pain reduction during one week of observation showed to be significantly higher (p = 0,045, η2 = 0,013) for the PEMF group (PPT: +83 bis +139%) compared to the placebo group (PPT: +10 bis +36%). There were no HSP70 associated effects.

CONCLUSIONS

A single bout of high energy PEMF led to an immediate pain relief in tendinopathy patients lasting at least for one week, but the hypothesized underlying HSP70 associated inflammatory pathway could not be confirmed.

Systematic Review and Meta-Analysis: Pharmacological and Nonpharmacological Interventions for Disruptive Mood Dysregulation Disorder

Objectives: Disruptive mood dysregulation disorder (DMDD) is a relatively new diagnosis that comprises severe, nonepisodic irritability and recurrent outbursts of emotional instability in adolescents. This meta-analysis examined the efficacy of the available pharmacological and nonpharmacological interventions for DMDD. Methods: Literature searches were conducted in July 2023. To determine relevant articles, 330 abstracts were reviewed, and 39 articles were identified for full review. A random-effects model was used for the meta-analysis, and a subgroup analysis was performed to assess the effects of study design and intervention type. Results: Eleven studies were reviewed, including six pharmacological and five nonpharmacological. Despite high heterogeneity in effects (I2 = 85%), we showed statistically significant improvements in irritability symptoms following intervention. We showed statistically significant enhancements in symptoms of irritability following the intervention. The subgroup analysis revealed that, compared with randomized controlled trials (RCTs), open trials showed significant improvements in irritability. In addition, drug intervention significantly improved irritability compared to nondrug interventions. Atomoxetine (ATX), optimized stimulants, and stimulants combined with other drugs and behavioral therapy effectively improved irritability. Conclusions: With research indicating potential benefits for irritability from a combination of pharmacological interventions and therapy, including ATX, stimulants in conjunction with antipsychotic or antidepressant medications, and cognitive-behavioral techniques such as Dialectical Behavior Therapy for Children. Future large-scale RCTs are essential to further explore and refine these treatment approaches, especially focusing on the efficacy of combining pharmacological with effective nonpharmacological to improve irritability and overall outcomes in this population.

Drug trials are more likely to disclose full placebo control information than non-drug trials: A cross-sectional study of participant information leaflets of placebo-controlled trials

Background

This study aimed to investigate whether placebo control is differently disclosed in drug and non-drug randomised clinical trial (RCT) participant information leaflets (PILs) and how this might affect participant blinding and direction of study outcomes.

Methods

PILs were obtained from trials registered in the International Standard Randomised Controlled Trial Number database via email. Placebo descriptions in PILs were categorised as Full Disclosure (FD), Partial Disclosure (PD), or Missing Information (MI). Associations between intervention type (drug or non-drug)/placebo disclosure (FD or PD/MI) and participant blinding success/trial outcome direction (positive or non-positive) were examined using a two-sided Fisher's exact test.

Results

Of 116 collected PILs, 56 % were for drug trials and 44 % were for non-drug trials. Among them, 88 PILs had the corresponding publications available and 68 reports specified primary outcomes. Drug trials were more likely to fully disclose placebo information than non-drug trials (92.3 % vs. 74.5 %, p < 0.05). However, the success rate of blinding was only reported in 3 out of 88 trial publications (3.4 %), precluding further analysis. Furthermore, there was no significant association between the direction of trial results and the type of intervention or placebo disclosure.

Conclusion

Our study findings suggest that drug and non-drug RCTs might differ in the way they reveal placebo control information. Further research is warranted to understand what leads to more common PD of placebo information in non-drug trials than drug trials and to determine the optimal placebo control disclosure in specific trial context.

The role of quality of life data as an endpoint for collecting real-world evidence within geroscience clinical trials

With geroscience research evolving at a fast pace, the need arises for human randomized controlled trials to assess the efficacy of geroprotective interventions to prevent age-related adverse outcomes, disease, and mortality in normative aging cohorts. However, to confirm efficacy requires a long-term and costly approach as time to the event of morbidity and mortality can be decades. While this could be circumvented using sensitive biomarkers of aging, current molecular, physiological, and digital endpoints require further validation. In this review, we discuss how collecting real-world evidence (RWE) by obtaining health data that is amenable for collection from large heterogeneous populations in a real-world setting can help speed up validation of geroprotective interventions. Further, we propose inclusion of quality of life (QoL) data as a biomarker of aging and candidate endpoint for geroscience clinical trials to aid in distinguishing healthy from unhealthy aging. We highlight how QoL assays can aid in accelerating data collection in studies gathering RWE on the geroprotective effects of repurposed drugs to support utilization within healthy longevity medicine. Finally, we summarize key metrics to consider when implementing QoL assays in studies, and present the short-form 36 (SF-36) as the most well-suited candidate endpoint.

Placebo response to sham electroacupuncture in patients with chronic functional constipation: A secondary analysis

BACKGROUND

Chronic severe functional constipation is a common disease that requires novel and effective treatment strategies. Acupuncture might constitute a promising therapeutic approach for chronic constipation, but it reportedly engenders an enhanced placebo response. Herein, we aimed to determine the magnitude of the placebo responses to electroacupuncture for constipation and identify its influencing factors.

METHODS

In this secondary analysis of a multicenter randomized trial, patients were randomized to a sham electroacupuncture group, which was administered for 8 weeks in 24 sessions of superficial needling at nonacupoints. The placebo response rates were assessed using three responder criteria: ≥3 complete spontaneous bowel movements per week (CSBMs/week), overall CSBM, and sustained CSBM. Logistic regression with backward selection method was employed to identify the potential factors that affected the placebo response.

KEY RESULTS

Overall, 539 patients were included in the study. The placebo response rate was 10.58%, 9.46%, and 9.09% according to the three aforementioned criteria, respectively. Those who exhibited more CSBMs/week at baseline were more likely to respond to sham electroacupuncture. Among patients with more than one CSBM per week at baseline, the response rates for achieving the criteria of ≥3 CSBMs per week, overall CSBM, and sustained CSBM were 25.40%, 30.16%, and 22.22%.

CONCLUSIONS AND INFERENCE

Electroacupuncture did not demonstrate a large placebo response in functional constipation treatment. The number of CSBMs at baseline may be a moderator of the placebo response to sham electroacupuncture. Thus, superficial needling sham acupuncture may be considered an ideal sham control for clinical trials of chronic constipation.

The importance of context (placebo effects) in conservative interventions for musculoskeletal pain: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVE

Contextual effects (e.g. patient expectations) may play a role in treatment effectiveness. This study aimed to estimate the magnitude of contextual effects for conservative, non-pharmacological interventions for musculoskeletal pain conditions. A systematic review and meta-analysis of randomized controlled trials (RCTs) that compared placebo conservative non-pharmacological interventions to no treatment for musculoskeletal pain. The outcomes assessed included pain intensity, physical functioning, health-related quality of life, global rating of change, depression, anxiety and sleep at immediate, short-, medium- and/or long-term follow-up.

DATABASES AND DATA TREATMENT

MEDLINE, EMBASE, CINAHL, Web of Science Core Collection, CENTRAL and SPORTDiscus were searched from inception to September 2021. Trial registry searches, backward and forward citation tracking and searches for prior systematic reviews were completed. The Cochrane risk of bias 2 tool was implemented.

RESULTS

The study included 64 RCTs (N = 4314) out of 8898 records. For pain intensity, a mean difference of (MD: -5.32, 95% confidence interval (CI): -7.20, -3.44, N = 57 studies with 74 outcomes, GRADE: very low) was estimated for placebo interventions. A small effect in favour of the placebo interventions for physical function was estimated (SMD: -0.22, 95% CI: -0.35, -0.09; N = 37 with 48 outcomes, GRADE: very low). Similar results were found for a broad range of patient-reported outcomes. Meta-regression analyses did not explain heterogeneity among analyses.

CONCLUSION

The study found that the contextual effect of non-pharmacological conservative interventions for musculoskeletal conditions is likely to be small. However, given the known effect sizes of recommended evidence-based treatments for musculoskeletal conditions, it may still contribute an important component.

SIGNIFICANCE

Contextual effects of non-pharmacological conservative interventions for musculoskeletal conditions are likely to be small for a broad range of patient-reported outcomes (pain intensity, physical function, quality of life, global rating of change and depression). Contextual effects are unlikely, in isolation, to offer much clinical care. But these factors do have relevance in an overall treatment context as they provide almost 30% of the minimally clinically important difference.

Balloon Eustachian Tuboplasty-A Feasible Double-Blinded Sham Surgery Randomized Clinical Trial Protocol to Study Efficacy

INTRODUCTION

Balloon Eustachian tuboplasty (BET) is used to treat obstructive Eustachian tube dysfunction (OETD) and recurrent otitis media with effusion (OME). However, there are no indisputable evidence of its efficacy. Here, we present a multicenter, double-blinded, randomized, placebo-controlled trial (MDRCT) design to evaluate the efficacy of BET, and the results of a pilot trial with 3- and 12-months' follow-up.

MATERIAL AND METHODS

This was a prospective MDRCT. For a pilot study, OETD (n = 10) and OME (n = 5) patients were recruited and followed. Detailed inclusion and exclusion criteria were used. Participants were randomized at beginning of the operation to active or sham surgery. All procedures were performed under local anesthesia. Controls were performed in double-blinded manner (both patient and physician), at 3 and 12 months after the procedure.

RESULTS

Altogether, 20 ears were treated and followed for 12 months, including 14 active BETs and 6 sham surgeries. Both the active and sham surgery were performed under local anesthesia without problems or deviations from the protocol. There were no differences in the preoperative symptoms (ETDQ-7) or objective measures (tympanometry, Valsalva and Toynbee maneuvers, tubomanometry, Eustachian tube score) between active and sham surgery arms. During follow-up, we noticed largely similar reduction in subjective symptoms and improvement in Eustachian tube score both in active and sham surgery arms.

CONCLUSIONS

The pilot study demonstrates that our MDRCT protocol is feasible, and that blinded RCTs are dearly needed to objectively measure the efficacy of BET.

LEVEL OF EVIDENCE

2 Laryngoscope, 134:1874-1881, 2024.

Placebo analgesia in physical and psychological interventions: Systematic review and meta-analysis of three-armed trials

BACKGROUND

The magnitude of placebo effects from physical and psychological 'sham' is unknown but could impact efficacy trials and treatment understanding. To quantify placebo effects, this systematic review of three-armed randomised controlled trials (RCTs) of physical and psychological interventions for pain compared outcomes in 'sham' control intervention and non-exposure arms.

METHODS

RCTs with treatment, 'sham' control intervention, and non-exposure groups were included, enrolling adults with any pain. A protocol was pre-registered (PROSPERO: CRD42023413324), and twelve databases searched from 2008 to July 2023. Trial methods and blinding were analysed descriptively and risk of bias assessed. Meta-analysis of pain measures at short-, medium- and long-term was performed with random-effects models of standardised mean differences (SMD).Studies were sub-grouped according to control intervention type.

RESULTS

Seventeen RCTs were included. The average short-term placebo effect was small (0.21 SMD, 0.1-0.33 95% CI, p = 0.0002, 1440 participants). It showed no heterogeneity (Tau2  = 0.1, I2  = 11%, p = 0.3), preventing meta-regression analyses of effect modifiers. However, sub-group analyses revealed larger placebo effects in manual control interventions compared to disabled devices and miscellaneous control interventions. Overall, placebo analgesia accounted for 39% of treatments' short-term effectiveness. No placebo effects were found at medium-term (7 RCTs, 381 participants) or long-term follow-up (3 RCTs, 173 participants).

CONCLUSIONS

The observed placebo analgesia has mechanistic and methodological implications, though its clinical importance may be limited. Control intervention design affects placebo effects, highlighting the importance of considering methodology in RCT interpretation. Review limitations include a small number of long-term studies and sample heterogeneity.

SIGNIFICANCE

This systematic review directly quantifies placebo effects from physical and psychological 'sham' control interventions and compares them to treatments' overall effectiveness. By doing so, the review enhances our understanding of placebo effects, their relative contribution in clinical trials, and their susceptibly to trial design. It poses further questions regarding the influence of blinding, participant expectations, and features of the therapeutic context. Overall, the insights provided by this review carry methodological significance and are important for the interpretation and synthesis of efficacy trials in this field.

Vitamin C deficiency can lead to pulmonary hypertension: a systematic review of case reports

BACKGROUND

In the early literature, unintentional vitamin C deficiency in humans was associated with heart failure. Experimental vitamin C deficiency in guinea pigs caused enlargement of the heart. The purpose of this study was to collect and analyze case reports on vitamin C and pulmonary hypertension.

METHODS

We searched Pubmed and Scopus for case studies in which vitamin C deficiency was considered to be the cause of pulmonary hypertension. We selected reports in which pulmonary hypertension was diagnosed by echocardiography or catheterization, for any age, sex, or dosage of vitamin C. We extracted quantitative data for our analysis. We used the mean pulmonary artery pressure (mPAP) as the outcome of primary interest.

RESULTS

We identified 32 case reports, 21 of which were published in the last 5 years. Dyspnea was reported in 69%, edema in 53% and fatigue in 28% of the patients. Vitamin C plasma levels, measured in 27 cases, were undetectable in 24 and very low in 3 cases. Diet was poor in 30 cases and 17 cases had neuropsychiatric disorders. Right ventricular enlargement was reported in 24 cases. During periods of vitamin C deficiency, the median mPAP was 48 mmHg (range 29-77 mmHg; N = 28). After the start of vitamin C administration, the median mPAP was 20 mmHg (range 12-33 mmHg; N = 18). For the latter 18 cases, mPAP was 2.4-fold (median) higher during vitamin C deficiency. Pulmonary vascular resistance (PVR) during vitamin C deficiency was reported for 9 cases, ranging from 4.1 to 41 Wood units. PVR was 9-fold (median; N = 5) higher during vitamin C deficiency than during vitamin C administration. In 8 cases, there was direct evidence that the cases were pulmonary artery hypertension (PAH). Probably the majority of the remaining cases were also PAH.

CONCLUSIONS

The cases analyzed in our study indicate that pulmonary hypertension can be one explanation for the reported heart failure of scurvy patients in the early literature. It would seem sensible to measure plasma vitamin C levels of patients with PH and examine the effects of vitamin C administration.

The placebo effect in randomized-controlled trials of medical treatments for chronic rhinosinusitis: A systematic review and meta-analysis

BACKGROUND

The placebo effect observed in clinical trials evaluating medical treatments for chronic rhinosinusitis (CRS) is not well understood. This systematic review and meta-analysis sought to characterize the placebo effect present within CRS outcomes.

METHODS

A systematic review of PubMed, Scopus, and Cumulated Index in Nursing and Allied Health Nursing (CINAHL) was performed. Randomized controlled trials (RCTs) evaluating medical treatments for CRS versus placebo were included. We assessed patient-reported (sino-nasal outcome test 22 [SNOT-22], nasal obstruction, sense of smell, nasal obstruction visual analogue score [VAS], sense of smell VAS, anterior rhinorrhea, and postnasal drip) and objective (Lund-Mackay Computed tomography (CT) score, peak nasal inspiratory flow [PNIF], nasal polyp scores, 40-item Smell Identification Test, serum IgE, and blood eosinophil levels) outcomes.

RESULTS

Twenty-one RCTs were included, comprising 1437 patients (mean age 49.2 years). Biologics were the most common treatment investigated (n = 9). Eleven studies administered background steroids along with placebo. Following placebo administration, multiple patient-reported outcomes significantly decreased, including SNOT-22 (mean difference -9.49, 95% confidence interval [CI] [-11.26, -7.73]), nasal obstruction (-0.33 [-0.54, -0.13]), sense of smell (-0.22 [-0.33, -0.11]), nasal obstruction VAS (-2.47 [-2.87, -2.06]), and loss of smell VAS (-2.31 [-4.14, -0.47]) scores. For objective measures, significant changes occurred in Lund-Mackay CT score (-0.82, [-1.48, -0.16]) and PNIF (4.70, [4.76, 24.64]) with placebo. Placebo arms had the greatest impact when no background medications were used.

CONCLUSIONS

Placebo treatments have a statistically and potentially clinically significant effect on patient-reported and some objective CRS outcomes. Further investigation is required to fully understand placebo effect, which could improve assessment of RCTs and impact patient care.

Boosting open-label placebo effects in acute induced pain in healthy adults (BOLPAP-study): study protocol of a randomized controlled trial

Introduction

Pain is a highly prevalent symptom in the hospital setting, but treatment options remain limited. Harnessing the placebo effect in an ethical manner could provide a new possibility to reduce pain in clinical practice. So called open-label placebos (OLP) have been shown to elicit significant effects in reducing acute pain. But, before implementation, more knowledge concerning the properties of OLPs is needed. This study aims to assess the duration of analgesic effects from OLP and to determine the possibility of boosting such effects.

Methods and analysis

This is the protocol of an ongoing (first patient enrolled in March 2023) single-site randomized trial investigating OLPs in two parts (i.e., substudies). In both parts, pain will be induced in healthy adults using an intradermal electrical stimulation model. Participants in Part 1 will have two study visits: An interventional visit with one OLP injection accompanied by an evidence-based treatment rationale and a control visit with no treatment. For Part 2, participants will be randomized into three groups: (1) A fixed-time "Booster" group including one single repetition of the OLP injection at a fixed time point, (2) an on-demand "Booster" group including one single repetition of the OLP injection on-demand, and (3) a control group who will receive just one OLP injection. Differences in pain ratings over time (using the Numeric Rating Scale) will be analyzed with several two-sample t-tests. The time point for a fixed-time "Booster" in Part 2 will be derived from Part 1 with additional statistical tools such as a broken-stick mixed-effect model.

Discussion

This study aims to further characterize the analgesic effects of OLPs. In doing so, it will provide valuable information needed for later implementation of OLPs in clinical practice, where they could play a role in multimodal analgesic concepts.

Ethics and dissemination

The "Ethikkommission Nordwest- und Zentralschweiz" (BASEC 2023-00296) approved the study protocol. Results of the analysis will be submitted for publication in a peer-reviewed journal.

Clinical Trial Registration

This study is registered at ClinicalTrials.gov (NCT05819476) and is listed in the Swiss National Registry at kofam.ch (SNCTP000005470).

Contextual effects: how to, and how not to, quantify them

The importance of contextual effects and their roles in clinical care controversial. A Cochrane review published in 2010 concluded that placebo interventions lack important clinical effects overall, but that placebo interventions can influence patient-reported outcomes such as pain and nausea. However, systematic reviews published after 2010 estimated greater contextual effects than the Cochrane review, which stems from the inappropriate methods employed to quantify contextual effects. The effects of medical interventions (i.e., the total treatment effect) can be divided into three components: specific, contextual, and non-specific. We propose that the most effective method for quantifying the magnitude of contextual effects is to calculate the difference in outcome measures between a group treated with placebo and a non-treated control group. Here, we show that other methods, such as solely using the placebo control arm or calculation of a 'proportional contextual effect,' are limited and should not be applied. The aim of this study is to provide clear guidance on best practices for estimating contextual effects in clinical research.

Placebo stimulates neuroplasticity in depression: implications for clinical practice and research

Neither psychological nor neuroscientific investigations have been able to fully explain the paradox that placebo is designed to be inert in randomized controlled trials (RCTs), yet appears to be effective in evaluations of clinical interventions in all fields of medicine and alternative medicine. This article develops the Neuroplasticity Placebo Theory, which posits that neuroplasticity in fronto-limbic areas is the unifying factor in placebo response (seen in RCTs) and placebo effect (seen in clinical interventions) where it is not intended to be inert. Depression is the disorder that has the highest placebo response of any medical condition and has the greatest potential for understanding how placebos work: recent developments in understanding of the pathophysiology of depression suggest that fronto-limbic areas are sensitized in depression which is associated with a particularly strong placebo phenomenon. An innovative linkage is made between diverse areas of the psychology and the translational psychiatry literature to provide supportive evidence for the Neuroplasticity Placebo Theory. This is underpinned by neuro-radiological evidence of fronto-limbic change in the placebo arm of antidepressant trials. If placebo stimulates neuroplasticity in fronto-limbic areas in conditions other than depression - and results in a partially active treatment in other areas of medicine - there are far reaching consequences for the day-to-day use of placebo in clinical practice, the future design of RCTs in all clinical conditions, and existing unwarranted assertions about the efficacy of antidepressant medications. If fronto-limbic neuroplasticity is the common denominator in designating placebo as a partially active treatment, the terms placebo effect and placebo response should be replaced by the single term "placebo treatment."

How Do Expectations Modulate Pain? A Motivational Perspective

Expectations can profoundly modulate pain experience, during which the periaqueductal gray (PAG) plays a pivotal role. In this article, we focus on motivationally evoked neural activations in cortical and brainstem regions both before and during stimulus administration, as has been demonstrated by experimental studies on pain-modulatory effects of expectations, in the hope of unraveling how the PAG is involved in descending and ascending nociceptive processes. This motivational perspective on expectancy effects on the perception of noxious stimuli sheds new light on psychological and neuronal substrates of pain and its modulation, thus having important research and clinical implications.

Placebo and nocebo effects and mechanisms associated with pharmacological interventions: an umbrella review

OBJECTIVES

This review aimed to summarise the existing knowledge about placebo and nocebo effects associated with pharmacological interventions and their mechanisms.

DESIGN

Umbrella review, adopting the Assessment of Multiple Systematic Reviews 2 tool for critical appraisal.

DATA SOURCES

MEDLINE/PubMed, Scopus, Web of Science, PsycINFO, Cochrane Central Register of Controlled Trial were searched in September 2022, without any time restriction, for systematic reviews, narrative reviews, original articles. Results were summarised through narrative synthesis, tables, 95% CI.

OUTCOME MEASURES

Mechanisms underlying placebo/nocebo effects and/or their effect sizes.

RESULTS

The databases search identified 372 studies, for a total of 158 312 participants, comprising 41 systematic reviews, 312 narrative reviews and 19 original articles. Seventy-three per cent of the examined systematic reviews were of high quality.Our findings revealed that mechanisms underlying placebo and/or nocebo effects have been characterised, at least in part, for: pain, non-noxious somatic sensation, Parkinson's disease, migraine, sleep disorders, intellectual disability, depression, anxiety, dementia, addiction, gynaecological disorders, attention-deficit hyperactivity disorder, immune and endocrine systems, cardiovascular and respiratory systems, gastrointestinal disorders, skin diseases, influenza and related vaccines, oncology, obesity, physical and cognitive performance. Their magnitude ranged from 0.08 to 2.01 (95% CI 0.37 to 0.89) for placebo effects and from 0.32 to 0.90 (95% CI 0.24 to 1.00) for nocebo effects.

CONCLUSIONS

This study provides a valuable tool for clinicians and researchers, identifying both results ready for clinical practice and gaps to address in the near future.

FUNDING

Università Cattolica del Sacro Cuore, Milan, Italy with the 'Finanziamento Ponte 2022' grant.

PROSPERO REGISTRATION NUMBER

CRD42023392281.

Placebo Response among Different Types of Sham Acupuncture for Low Back Pain: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Low back pain (LBP) is a prevalent and debilitating condition that poses a significant burden on healthcare systems. Acupuncture has been proposed as a promising intervention for LBP, but the evidence supporting its specific effect is insufficient, and the use of sham acupuncture as a control in clinical trials presents challenges due to variations in sham acupuncture techniques and the magnitude of the placebo effect.

OBJECTIVE

To investigate the magnitude of the placebo response of sham acupuncture in trials of acupuncture for nonspecific LBP, and to assess whether different types of sham acupuncture are associated with different responses.

METHODS

Four databases including PubMed, EMBASE, MEDLINE, and the Cochrane Library were searched through April 15, 2023, and randomized controlled trials (RCTs) were included if they randomized patients with LBP to receive acupuncture or sham acupuncture intervention. The main outcomes included the placebo response in pain intensity, back-specific function and quality of life. Placebo response was defined as the change in these outcome measures from baseline to the end of treatment. Random-effects models were used to synthesize the results, standardized mean differences (SMDs, Hedges'g) were applied to estimate the effect size.

RESULTS

A total of 18 RCTs with 3,321 patients were included. Sham acupuncture showed a noteworthy pooled placebo response in pain intensity in patients with LBP [SMD -1.43, 95% confidence interval (CI) -1.95 to -0.91, I2=89%]. A significant placebo response was also shown in back-specific functional status (SMD -0.49, 95% CI -0.70 to -0.29, I2=73%), but not in quality of life (SMD 0.34, 95% CI -0.20 to 0.88, I2=84%). Trials in which the sham acupuncture penetrated the skin or performed with regular needles had a significantly higher placebo response in pain intensity reduction, but other factors such as the location of sham acupuncture did not have a significant impact on the placebo response.

CONCLUSIONS

Sham acupuncture is associated with a large placebo response in pain intensity among patients with LBP. Researchers should also be aware that the types of sham acupuncture applied may potentially impact the evaluation of the efficacy of acupuncture. Nonetheless, considering the nature of placebo response, the effect of other contextual factors cannot be ruled out in this study. (PROSPERO registration No. CRD42022304416).

Mesenchymal stem cell therapy in aqueous deficient dry eye disease

ENGLISH SUMMARY

Dry eye disease (DED) is characterized by ocular dryness, irritation and blurred vision and has a significant impact on the patient's quality of life. This condition can be particularly severe in patients with aqueous deficient dry eye disease (ADDE) due to Sjögren's syndrome (SS), an autoimmune disease that affects the lacrimal and salivary glands. Current treatments for ADDE are often limited to symptomatic relief. A literature review was conducted to explore the current surgical interventions used or tested in humans with ADDE (I). These interventions include procedures involving the eyelids and tear ducts, transplantation of amniotic membrane or salivary glands, injections around the tear ducts and cell-based injections into the lacrimal gland (LG). Each treatment has its advantages and disadvantages; however, treating dry eyes in patients with SS presents a particular challenge due to the systemic nature of the disease. Moreover, there is a need for new therapeutic options. Mesenchymal stem cells (MSCs) are a type of stem cell that have shown promise in regenerating damaged tissue and reducing inflammation in various diseases. Previous studies in animal models have suggested that MSCs could be effective in treating ADDE. Thus, this thesis aims to investigate the safety and efficacy of injecting MSCs into the LG as a treatment option for patients with ADDE secondary to SS. The study also aims to see this treatment in light of existing and novel investigational treatment options. The clinical studies conducted for this thesis are the first of their kind in humans. MSCs derived from healthy donors' adipose tissue (ASCs) were cultured in a laboratory, frozen and thawed ready for use. In the safety study, we performed the first human trial involving the administration of a single injection of ASCs into the LG of one eye in seven patients suffering from severe ADDE (II). The primary objective was to test the safety of this treatment, while the secondary objective was to assess improvements in subjective and objective signs of dry eye. The results of the trial showed no serious side effects within 4 months of follow-up after treatment. On average, there was a 40% reduction in dry eye symptoms assessed with the Ocular Surface Disease Index (OSDI) questionnaire. Additionally, in the treated eye, there was a significant decrease in tear osmolarity, an increase in tear film stability and an increase in tear production. To further investigate the efficacy of this treatment, our research group performed a clinical, randomized study aiming to compare the ASC injection into the LG with the injection of a vehicle (the excipient in which the ASCs are dissolved) and observation (no intervention) (III). The study involved 20 subjects receiving ASC injection, 20 subjects receiving vehicle injection and 14 patients being observed without intervention. The subjects were examined to assess the outcomes with a 12-month follow-up after treatment. Both intervention groups showed a significant reduction in subjective dry eye symptoms of approximately 40%. This improvement was evident at the 1-week follow-up and persisted until the 12-month follow-up. The observation group did not experience any change in OSDI score. The ASCs group exhibited a significant mean increase in non-invasive tear break-up time (NIKBUT) of 6.48 s (149%) at the four-week follow-up, which was significantly higher than that in the vehicle group (p = 0.04). Moreover, the ASCs group showed a significant increase in NIKBUT compared to that in the observation group at the 12-month follow-up (p = 0.004). In both the ASCs and vehicle group, a significant increase in Schirmer test scores at the 4-month follow-up and the 12-month follow-up was observed. In conclusion, this thesis contributes valuable findings with a new treatment option for patients with dry eye disease. Injection of ASCs into the LG was shown to be safe and to improve subjective dry eye symptoms and specifically the tear film stability in patients with ADDE due to SS. Compared to other treatment modalities of ADDE, this treatment has greater potential, as ASCs could potentially be used as an anti-inflammatory therapeutic option for managing DED of other causes as well. RESUMÉ (DANISH SUMMARY): Tørre øjne, karakteriseret ved tørhedsfornemmelse og irritation af øjnene samt sløret syn, har en betydelig indvirkning på patientens livskvalitet. Denne tilstand kan vaere saerligt alvorlig hos patienter med nedsat tåreproduktion (ADDE) som følge af Sjögrens syndrom (SS), en autoimmun sygdom, der påvirker tårekirtlerne og spytkirtlerne. Nuvaerende behandlinger for ADDE er ofte begraenset til symptomlindring. Vi gennemførte en litteraturgennemgang for at undersøge, hvilke nuvaerende kirurgiske behandlingsmetoder, der anvendes eller testes hos patienter med ADDE (I). Disse interventioner inkluderer procedurer, der involverer øjenlåg og tårekanaler, transplantation af amnionhinde eller spytkirtler, injektioner omkring tårekanalerne samt cellebaserede injektioner i tårekirtlen. Hver behandling har sine fordele og ulemper, men behandling af tørre øjne hos patienter med SS udgør en saerlig udfordring på grund af sygdommens systemiske udbredning, og der er behov for nye behandlingsmuligheder. Mesenkymale stamceller (MSCs) er en type stamcelle, der har vist lovende resultater med hensyn til at regenerere beskadiget vaev og reducere inflammation i forskellige sygdomme. Tidligere undersøgelser i dyremodeller har indikeret, at MSCs kan vaere en effektiv behandling af ADDE. Denne afhandling har til formål at undersøge sikkerheden og effekten af injektion af MSCs i tårekirtlen som en mulig behandling til patienter med ADDE som følge af SS. Afhandlingen sigter også mod at sammenligne denne behandling med andre eksisterende, kirurgiske behandlingsmuligheder af ADDE. Som led i dette projekt udførte vi de første kliniske forsøg af sin art i mennesker. MSCs fra raske donorers fedtvaev (ASCs) blev dyrket i et laboratorium, frosset ned og er optøet klar til brug. Det første mål var at teste sikkerheden ved denne behandling og sekundaert at undersøge behandlingens effekt. For at undersøge dette modtog syv forsøgspersoner med svaer ADDE én injektion med ASCs i tårekirtlen på det ene øje (II). Resultaterne af forsøget viste ingen alvorlige bivirkninger inden for fire måneders opfølgning efter behandlingen. I gennemsnit fandt vi yderligere en 40% reduktion i symptomer på tørre øjne vurderet med et spørgeskema, og en markant stigning i tåreproduktionen og af tårefilmens stabilitet i det behandlede øje. For yderligere at undersøge effekten af denne behandling udførte vi et klinisk, randomiseret forsøg med det formål at sammenligne injektion af ASCs i tårekirtlen med injektion af en kontrolopløsning (vaesken, hvor stamcellerne var opløst) og observation (ingen intervention) (III). Studiet omfattede 20 forsøgspersoner, der modtog ASC-injektion, 20 forsøgspersoner, der modtog injektion af kontrolopløsningen, og 14 forsøgspersoner i observationsgruppen. Forsøgspersonerne blev undersøgt med en opfølgningstid på 12 måneder efter behandling. Begge interventionsgrupper viste en betydelig reduktion på ca. 40% i subjektive symptomer på tørre øjne. Denne forbedring var betydelig allerede ved opfølgning efter en uge og varede ved 12 måneder efter behandling. Observationsgruppen oplevede ingen betydelig aendring i symptomer. ASCs gruppen viste desuden en signifikant stigning i tårefilmsstabiliteten (NIKBUT) på 6,48 sekunder (149%) ved opfølgning efter fire uger, hvilket var markant højere end efter injektion af kontrolopløsning (p = 0,04). Desuden viste ASCs gruppen en betydelig stigning i NIKBUT sammenlignet med observationsgruppen ved opfølgning efter 12 måneder (p = 0,004). Både injektion af ASCs og kontrolopløsning medførte en betydelig stigning i tåreproduktionen ved opfølgning fire måneder og 12 måneder efter behandling. Denne afhandling bidrager med vigtige resultater inden for en ny behandlingsmulighed af tørre øjne. Injektion af ASCs i tårekirtlen viste sig at vaere sikker, forbedrede subjektive symptomer på tørre øjne og øgede saerligt tårfilmens stabilitet hos patienter med ADDE på grund af SS. Sammenlignet med andre behandlingsmuligheder for ADDE har denne behandling vist et stort potentiale. ASCs kan muligvis også bruges som en anti-inflammatorisk behandling af tørre øjne af andre årsager i fremtiden.

The power of the placebo effect in diabetes: A systematic review and meta-analysis

This review aims to identify the magnitude of the placebo effect in people with type 2 diabetes mellitus. Literature research was conducted Medline, Embase and Virtual Health Library for studies published between the date of inception and June 2021. The eligibility criteria included randomized controlled trials, showing comparison to placebo, having participants with type 2 diabetes mellitus, and having glycated hemoglobin (HbA1c) as the primary outcome. Meta-analysis was conducted with the effect of changing HbA1c in relation to the baseline. Exploration of heterogeneity was performed.The meta-analysis showed an increase in the average of HbA1c compared to the baseline of 0.14% (95% CI: 0.07-0.21). There was a significant difference between follow-up times (p = 0.03) and between administration routes (p = 0.01), with an increase in HbA1c in the oral route [0.15% (95% CI: 0.07-0.23)]. The meta-regression of the year of publication showed a significant downward trend (p = 0.01) of the increase in HbA1c compared to the baseline.In this study, the expected placebo effect of Hba1c reduction was not found; instead, higher Hba1c levels were observed in the control groups, although this effect was reduced over the years. Registration: PROSPERO ID CRD42020172797.

Descriptions of sham acupuncture in randomised controlled trials: a critical review of the literature

BACKGROUND

Sham acupuncture is usually used to assess the specific effects of acupuncture. However, the reporting quality of sham acupuncture remains unclear despite its critical importance in understanding and analyzing the effects of acupuncture. This paper presents a literature review aimed at assessing the quality of reporting of sham acupuncture in randomized controlled trials (RCTs) based on STRICTA 2010 and TIDieR-Placebo.

METHODS

Three electronic English-language databases (PubMed, MEDLINE and Embase) were searched from inception to March 7, 2022, and RCTs of sham acupuncture were identified. The reporting quality of sham acupuncture was assessed in accordance with the items recommended in STRICTA 2010 and TIDieR-Placebo. The reporting quality of other items related to sham acupuncture apart from items from these two checklists was also captured to further assess the reporting quality of sham acupuncture.

RESULTS

A total of 609 eligible studies were included. For all of the items recommended in STRICTA 2010 and TIDieR-Placebo, 100% of the studies reported a brief name that described the sham acupuncture, 93.9% studies reported the needle type, and 90.0% reported the names of the points used. Other items for which the reporting rates were above 50% included the number, frequency and duration of treatment sessions; needle retention time; and number of needle insertions per subject per session. Overall, 49.4% of the studies revealed the rationale why sham acupuncture was chosen, 39.7% of the studies involving insertion processes reported the depth of insertion, and 37.9% of the studies reported the needle manufacturer. Other items for which the reporting rates were below 30% included practitioner-related information, response sought, evaluation of blinding, intervention mode and environment, assisting tools, and the extent to which the treatment was varied. The items "Modifications", "How well (planned)" and "How well (actual)" were not reported in any of the analyzed studies.

CONCLUSIONS

The overall reporting quality of sham acupuncture in RCTs was suboptimal. Although STRICTA 2010 and TIDieR-Placebo could be beneficial for describing sham acupuncture, neither can offer recommendations specifically for sham acupuncture. There is thus an urgent need to develop specialized guidelines for reporting sham acupuncture in clinical trials.

Influence of active versus placebo control on treatment responses in randomised controlled trials in rheumatoid arthritis

OBJECTIVES

To investigate whether treatment effects of pharmaceutical compounds compared with placebo controls are systematically different to the effects of the same compounds compared with active treatment controls in rheumatoid arthritis (RA) clinical trials.

METHODS

We systematically identified randomised controlled trials (RCTs) in RA, and matched active treatment arms with comparable regimens, populations, background therapy, and outcome reporting, by the nature of their control group (active comparator or placebo). Medline, EMBASE and CENTRAL were used to identify RCTs investigating disease modifying anti-rheumatic drug therapies until December 2021. Using mixed-model logistic regression we estimated OddsRatios (OR) for achieving an American College of Rheumatology (ACR) 20/50/70% response at weeks 12 and 24. Risk of bias was assessed using the Cochrane Tool.

RESULTS

We screened 8328 studies and included 40 for analysis after detailed review of 590 manuscripts; unique compounds had significantly higher responses in active comparator trials compared with their effects observed in placebo controlled trials, with ORs of 1.67 (95% CI 1.46 to 1.91; p<0.001) for ACR20, 1.50 (95% CI 1.29 to 1.75; p<0.001) for ACR50 and 1.65 (95% CI 1.30 to 2.10; p<0.001) for ACR70 (week 12); corresponding ORs for ACR 20, 50, and 70 (week 24) were 1.93 (95% CI 1.50 to 2.48; p<0.001), 1.75 (95% CI 1.32 to 2.33; p<0.001) and 1.68 (95% CI 1.21 to 2.34; p<0.001), respectively. Sensitivity analyses showed consistent results.

CONCLUSION

Placebo controlled trials lead to smaller effect sizes of active compounds in RCTs compared with the same compound in head-to-head trials. This difference may be explained by potential nocebo effects in placebo-controlled settings and needs to be considered when interpreting head-to-head and placebo-controlled trials, by patients, investigators, sponsors and regulatory agencies.

High-dose opioids for chronic non-cancer pain: an overview of Cochrane Reviews

BACKGROUND

This overview was originally published in 2017, and is being updated in 2022.  Chronic pain is typically described as pain on most days for at least three months. Chronic non-cancer pain (CNCP) is any chronic pain that is not due to a malignancy. Chronic non-cancer pain in adults is a common and complex clinical issue, for which opioids are prescribed by some physicians for pain management. There are concerns that the use of high doses of opioids for CNCP lacks evidence of effectiveness, and may increase the risk of adverse events.

OBJECTIVES

To describe the evidence from Cochrane Reviews and overviews regarding the efficacy and safety of high-dose opioids (defined as 200 mg morphine equivalent or more per day) for CNCP.

METHODS

We identified Cochrane Reviews and overviews by searching the Cochrane Database of Systematic Reviews in The Cochrane Library. The date of the last search was 21 July 2022. Two overview authors independently assessed the search results. We planned to analyse data on any opioid agent used at a high dose for two weeks or more for the treatment of CNCP in adults.

MAIN RESULTS

We did not identify any reviews or overviews that met the inclusion criteria. The excluded reviews largely reflected low doses or titrated doses, where all doses were analysed as a single group; we were unable to extract any data for high-dose use only.

AUTHORS' CONCLUSIONS

There is a critical lack of high-quality evidence, in the form of Cochrane Reviews, about how well high-dose opioids work for the management of CNCP in adults, and regarding the presence and severity of adverse events.  No evidence-based argument can be made on the use of high-dose opioids, i.e. 200 mg morphine equivalent or more daily, in clinical practice. Considering that high-dose opioids have been, and are still being used in clinical practice to treat CNCP, knowing about the efficacy and safety of these higher doses is imperative.

Proportion attributable to contextual effects in general medicine: a meta-epidemiological study based on Cochrane reviews

OBJECTIVES

Our objectives were to examine the magnitude of the proportion attributable to contextual effects (PCE), which shows what proportion of the treatment arm response can be achieved by the placebo arm across various interventions, and to examine PCE variability by outcome type and condition.

DESIGN

We conducted a meta-epidemiological study.

SETTING

We searched the Cochrane Database of Systematic Reviews with the keyword 'placebo' in titles, abstracts and keywords on 1 January 2020.

PARTICIPANTS

We included reviews that showed statistically significant beneficial effects of the intervention over placebo for the first primary outcome.

MAIN OUTCOME MEASURES

We performed a random-effects meta-analysis to calculate PCEs based on the pooled result of each included review, grouped by outcome type and condition. The PCE quantifies how much of the observed treatment response can be achieved by the contextual effects.

PUBLIC AND PATIENT INVOLVEMENT STATEMENT

No patient or member of the public was involved in conducting this research.

RESULTS

We included 328 out of 3175 Cochrane systematic reviews. The results of meta-analyses showed that PCEs varied greatly depending on outcome type (I²=98%) or condition (I²=98%), but mostly lie between 0.40 and 0.95. Overall, the PCEs were 0.65 (95% CI 0.59 to 0.72) on average. Subjective outcomes were 0.50 (95% CI 0.41 to 0.59), which was significantly smaller than those of semiobjective (PCE 0.78; 95% CI 0.72 to 0.85) or objective outcomes (PCE 0.94; 95% CI 0.91 to 0.97).

CONCLUSIONS

The results suggest that much of the observed benefit is not just due to the specific effect of the interventions. The specific effects of interventions may be larger for subjective outcomes than for objective or semiobjective outcomes. However, PCEs were exceptionally variable. When we evaluate the magnitude of PCEs, we should consider each PCE individually, for each condition, intervention and outcome in its context, to assess the importance of an intervention for each specific clinical setting.

Estimation of placebo effect in randomized placebo-controlled trials for moderate or severe vasomotor symptoms: a meta-analysis

OBJECTIVE

The Food and Drug Administration guidance recommended that for the indication of vasomotor symptoms (VMS), studies should enroll participants with minimum of seven to eight moderate to severe VMS per day at baseline, and coprimary endpoints should be the mean change in frequency/severity at weeks 4 and 12. This study aimed to estimate placebo effects in randomized controlled trials (RCTs) fulfilling this guidance.

METHODS

PubMed was searched using the following terms: "vasomotor symptom or hot flash or hot flashes or hot flash or hot flashes [title/abstract]," "menopause or climacteric," "RCT or randomized controlled or randomized controlled," "placebo [title/abstract]," and "frequency or severity." Inclusion criteria were as follows: (1) placebo controlled RCTs, (2) enrolling women with moderate or severe VMS with a minimal frequency more than seven to eight times per day or 50 times per week, and (3) efficacy measurements including mean change in VMS frequency from baseline at week 12. A random-effects model was used in the meta-analysis.

RESULTS

Seventeen studies were included for the estimation of VMS frequency reduction and 13 studies for severity. Estimated change of VMS frequency in placebo arms was -5.44 times per day (95% CI, -5.81 to -5.07 times per day) at week 12. For VMS severity, the estimated change at week 12 was -0.36 (95% CI, -0.46 to -0.27).

CONCLUSION

Substantial and consistent placebo effects were observed in RCTs for VMS treatment. These data suggest a reduction of 5.44 times per day in frequency and 0.36 in severity might be observed as a placebo effect.

Savor the flavor: A randomized double-blind study assessing taste-enhanced placebo analgesia in healthy volunteers

Placebo effects substantially contribute to analgesic treatment outcomes and might be leveraged to enhance gold-standard treatments. The taste of oral medications has been proposed to boost placebo effects. Here, we aimed at estimating how far the taste of an oral medication enhances placebo analgesia. We conducted a randomized, double-blind, between-group, single-visit study, with pre-treatment baseline. Over the course of three substudies, 318 healthy volunteers (297 included) were tested in a clinical trial setting. Participants were subjected to experimental tonic cold water pain (cold pressor test) before and after receiving taste-neutral (water), or bitter (quinine), or sweet (saccharin), or no placebo drops. Pre- versus post-treatment changes in area under the pain rating curve, the main outcome, indicated that placebo treatment showed a small analgesic effect versus no treatment. Added taste induced placebo enhancement in the very small effect size range, but accounted for a substantial portion of the overall placebo effect. No noteworthy advantage of sweet over bitter placebo was observed. An exploration of heart rate (HR) recordings indicated that placebo treatments were associated with an increase in peak HR-response to cold water, but these were not associated with placebo analgesia at an individual level. Placebo treatments were associated with minimal side effects. These results indicate that added taste may be an easy-to-implement, cost-effective, and safe way to optimize treatment outcomes and that taste-neutral preparations may reduce placebo-related outcome variance in clinical trials. Further studies are needed to test if these findings can be translated into clinical scenarios.

Effectiveness of 38% Silver Diamine Fluoride in Reducing Dentine Hypersensitivity on Exposed Root Surface in Older Chinese Adults: Study Protocol for a Randomised Double-Blind Study

Background: Dentine hypersensitivity on an exposed root surface induces pain, affects daily oral hygiene practice, limits dietary choices and negatively affects quality of life. Silver diamine fluoride is marketed in the United States as a desensitising agent, but well-designed clinical trials are limited. This study evaluates the anti-hypersensitivity effect of silver diamine fluoride on hypersensitive teeth due to an exposed root surface in older Chinese adults. Methods/design: We will conduct a randomised double-blind clinical trial with a sample size of at least 148 Chinese older adults aged 65 or above who have dentine hypersensitivity due to an exposed root surface. We will collect written consent before the study. A trained examiner will examine the participants’ teeth with a blast of compressed air from a 3-in-1 syringe. Those adults who report a self-perceived sensitivity score (SS) (0 to 10) of 8 or more on at least one tooth with an exposed root surface will be recruited. The recruited older adults will be randomly allocated into two groups using a block randomisation of six. Group 1 participants will receive the application of 38% silver diamine fluoride solution every 4 weeks. Group 2 participants will receive the application of 5% potassium nitrate solution every 4 weeks. Dietary advice, oral hygiene instruction and fluoride toothpaste at 1450 ppm will be provided to participants in both groups. The same trained examiner will perform follow-up examinations for the participants and determine the dentine hypersensitivity in SS of the most hypersensitive tooth (with the highest pre-treatment SS) immediately after the intervention and at 4-week and 8-week intervals. Discussion: There is no consensus on the standard of care for a professionally applied desensitising agent in older adults. This trial will provide evidence for clinicians to devise an effective dental care plan for older adults with dentine hypersensitivity. Trial registration: NCT05392868 Registered on 22 May 2022.

Informed Consent for Placebo-Controlled Trials: Do Ethics and Science Conflict?

The use of a placebo has been considered the best method for controlling bias in a prospective randomized clinical trial and provides the most rigorous test of treatment efficacy for evaluating a medical therapy. Placebos commonly produce clinically important effects particularly in studies where the primary outcomes are subjective. Yet the potential beneficial or harmful effects of placebos are often not addressed in designing a clinical trial, calculating the sample size, seeking consent, or interpreting clinical trial results. In this manuscript, we use an actual study to indicate three approaches that might be considered in seeking informed consent for placebo-controlled trials, and we explore the fundamental ethical and scientific complexities involved with each.

Placebo: a brief updated review

Our aims were to provide updated information on placebo/nocebo effect and the potential use of placebo in clinical practice. This article can only provide a rough overview on the placebo and nocebo effect and is intended to serve as a starting point for the reader to go deeper into the corresponding literature. The placebo effect has been observed in multiple medical conditions, after oral administration, with manual therapies as well as with surgery and invasive procedures. The use of placebo in clinical trials is fundamental, although the ethics of its use is under discussion. The placebo may behave like a drug from the pharmacokinetic and pharmacodynamic point of view and can also be associated with adverse events (nocebo effect). Placebo can modify treatment by increasing or decreasing the effects of drugs. The factors associated with the occurrence of placebo effect are multiple, but in addition to those that depend on the placebo itself, the doctor-patient relationship would be the most important. As a result of findings that were published in the last two decades, the psycho-neurobiological basis of placebo is becoming better understood, although further studies are needed. In conclusion, the placebo effect in the clinic exhibits weak to moderate intensity. Placebo, in addition to its use in the clinical trial, should be considered another therapeutic remedy either as stand alone or in association with treatment, and could be useful in certain circumstances. The use of placebo should be regulated by the European health authorities through a guide in clinical practice that will improve patient care.

Differences between experimental and placebo arms in manual therapy trials: a methodological review

BACKGROUND

To measure the specific effectiveness of a given treatment in a randomised controlled trial, the intervention and control groups have to be similar in all factors not distinctive to the experimental treatment. The similarity of these non-specific factors can be defined as an equality assumption. The purpose of this review was to evaluate the equality assumptions in manual therapy trials.

METHODS

Relevant studies were identified through the following databases: EMBASE, MEDLINE, SCOPUS, WEB OF SCIENCE, Scholar Google, clinicaltrial.gov, the Cochrane Library, chiloras/MANTIS, PubMed Europe, Allied and Complementary Medicine (AMED), Physiotherapy Evidence Database (PEDro) and Sciencedirect. Studies investigating the effect of any manual intervention compared to at least one type of manual control were included. Data extraction and qualitative assessment were carried out independently by four reviewers, and the summary of results was reported following the PRISMA statement.

RESULT

Out of 108,903 retrieved studies, 311, enrolling a total of 17,308 patients, were included and divided into eight manual therapy trials categories. Equality assumption elements were grouped in three macro areas: patient-related, context-related and practitioner-related items. Results showed good quality in the reporting of context-related equality assumption items, potentially because largely included in pre-existent guidelines. There was a general lack of attention to the patient- and practitioner-related equality assumption items.

CONCLUSION

Our results showed that the similarity between experimental and sham interventions is limited, affecting, therefore, the strength of the evidence. Based on the results, methodological aspects for planning future trials were discussed and recommendations to control for equality assumption were provided.

Manual acupuncture as prophylaxis for migraine without aura: study protocol for a multi-center, randomized, single-blinded trial

BACKGROUND

Migraine is a highly prevalent neurological disorder. It is the third most prevalent disorder and the seventh highest cause of disability worldwide. Acupuncture may be a viable prophylactic treatment option for frequent or uncontrolled migraine. Clinical studies comparing acupuncture and placebo acupuncture have not reached a consistent conclusion in confirming whether acupuncture is effective in migraine prophylaxis. The effect of acupuncture mainly depends on acupoints and needles operation. We found that the design of the placebo acupuncture in previous studies included shallow needling at sham acupoints, non-penetrating needling at sham acupoints, and needling at inactive acupuncture points to achieve the inert effect of control group, but the non-penetrating needling at true acupoints was ignored. This randomized controlled trial aims to use true acupoints for non-penetrating acupuncture as control to evaluate the efficacy of manual acupuncture for the prophylaxis of migraine without aura (MWoA).

METHODS/DESIGN

This is a single-blinded, randomized, controlled, prospective, multi-center trial with two parallel treatment groups. A total of 198 eligible patients with MWoA will be randomly divided into two groups (1:1 allocation ratio). The intervention group will receive manual acupuncture and the control group will receive placebo acupuncture (non-penetrating). Patients will receive three acupuncture treatment sessions per week for 4 consecutive weeks. All patients will then receive a 12-week follow-up.

DISCUSSION

In this study, we are evaluating the efficacy and safety of manual acupuncture in the prophylaxis of MWoA. The placebo control is using non-penetrating needling verum acupoints. It is essential to determine an appropriate control method to ensure the methodological quality of a randomized controlled trial.

TRIAL REGISTRATION

The trial has been registered in the Chinese Clinical Trial Registry (approval no. ChiCTR2000032308 ) in April 2020.

Influence of motivational placebo-related factors on the effects of exercise treatment in depressive adolescents

Recent meta-analyses reveal a moderate effect of physical activity (PA) in the treatment of adolescent depression. However, not only the underlying neurobiological mechanisms, also the influences of placebo-related motivational factors (beliefs and expectancies in sporting, enjoyment and prior sports experiences), are still unclear. Based on the data of our prior study "Mood Vibes", we hypothesized that placebo-inherent factors like positive prior sports experiences and motivational factors, (positive beliefs, expectancies, and enjoyment related to PA), would increase the effects of an add-on exercise-therapy in juvenile depression. From 64 included depressed adolescents, 41 underwent an intensive add-on PA-therapy. Motivational factors were assessed using sport-specific scales. The changes in depression scores under treatment were rated by self-rating scale (German "Childhood Depression Inventory", (DIKJ)). A mixed model for repeated measures (MMRM) was used to analyze the effects of the different motivational variates on DIKJ. While prior sports experiences had no impact, motivational factors showed a significant effect on PA-induced changes in DIKJ scores (p = 0.002). The demotivated participants improved less, whereas it was sufficient to be neutral towards sporting to benefit significantly more. Motivational placebo-related factors (beliefs, expectancies and enjoyment regarding PA) affected the outcomes of an exercise treatment in depressed adolescents. Yet, a neutral mindset was sufficient to profit more from PA. Prior sporting in the sense of positive conditioning and as a protective factor did not play a role. Knowledge about these influences could in a second step help to develop tailored therapies.

Great Expectations: recommendations for improving the methodological rigor of psychedelic clinical trials

RATIONALE

Psychedelic research continues to garner significant public and scientific interest with a growing number of clinical studies examining a wide range of conditions and disorders. However, expectancy effects and effective condition masking have been raised as critical limitations to the interpretability of the research.

OBJECTIVE

In this article, we review the many methodological challenges of conducting psychedelic clinical trials and provide recommendations for improving the rigor of future research.

RESULTS

Although some challenges are shared with psychotherapy and pharmacology trials more broadly, psychedelic clinical trials have to contend with several unique sources of potential bias. The subjective effects of a high-dose psychedelic are often so pronounced that it is difficult to mask participants to their treatment condition; the significant hype from positive media coverage on the clinical potential of psychedelics influences participants' expectations for treatment benefit; and participant unmasking and treatment expectations can interact in such a way that makes psychedelic therapy highly susceptible to large placebo and nocebo effects. Specific recommendations to increase the success of masking procedures and reduce the influence of participant expectancies are discussed in the context of study development, participant recruitment and selection, incomplete disclosure of the study design, choice of active placebo condition, as well as the measurement of participant expectations and masking efficacy.

CONCLUSION

Incorporating the recommended design elements is intended to reduce the risk of bias in psychedelic clinical trials and thereby increases the ability to discern treatment-specific effects of psychedelic therapy.

HOW DO THEY ADD UP? THE INTERACTION BETWEEN THE PLACEBO AND TREATMENT EFFECT: A SYSTEMATIC REVIEW

Aim

The placebo effect and the specific effect are often thought to add up (additive model). Whether additivity holds can dramatically influence the external validity of a trial. This assumption of additivity was tested by Kleijnen et al in 1994 but the data produced since then have not been synthetized. In this review, we aimed to systematically review the literature to determine whether additivity held.

Methods

We searched Medline and PsychInfo up to 10 January 2019. Studies using the balanced placebo design (BPD), testing two different strengths of placebos, were included. The presence of interaction was evaluated by comparing each group in the BPD with analysis of variance or covariance.

Results

Thirty studies were included and the overall risk of bias was high: four found evidence of additivity and 16 studies found evidence of interaction (seven had evidence of positive additivity).

Conclusion

Evidence of additivity between placebo and specific features of treatments was rare in included studies. We suggest interventions for placebo‐sensitive ailments should be tested in trials designed to take interactions seriously once an exploratory RCTs has proven their efficacy with sufficient internal validity.

Control interventions in randomised trials among people with mental health disorders

BACKGROUND

Control interventions in randomised trials provide a frame of reference for the experimental interventions and enable estimations of causality. In the case of randomised trials assessing patients with mental health disorders, many different control interventions are used, and the choice of control intervention may have considerable impact on the estimated effects of the treatments being evaluated.

OBJECTIVES

To assess the benefits and harms of typical control interventions in randomised trials with patients with mental health disorders. The difference in effects between control interventions translates directly to the impact a control group has on the estimated effect of an experimental intervention. We aimed primarily to assess the difference in effects between (i) wait-list versus no-treatment, (ii) usual care versus wait-list or no-treatment, and (iii) placebo interventions (all placebo interventions combined or psychological, pharmacological, and physical placebos individually) versus wait-list or no-treatment. Wait-list patients are offered the experimental intervention by the researchers after the trial has been finalised if it offers more benefits than harms, while no-treatment participants are not offered the experimental intervention by the researchers.

SEARCH METHODS

In March 2018, we searched MEDLINE, PsycInfo, Embase, CENTRAL, and seven other databases and six trials registers.

SELECTION CRITERIA

We included randomised trials assessing patients with a mental health disorder that compared wait-list, usual care, or placebo interventions with wait-list or no-treatment .

DATA COLLECTION AND ANALYSIS

Titles, abstracts, and full texts were reviewed for eligibility. Review authors independently extracted data and assessed risk of bias using Cochrane's risk of bias tool. GRADE was used to assess the quality of the evidence. We contacted researchers working in the field to ask for data from additional published and unpublished trials. A pre-planned decision hierarchy was used to select one benefit and one harm outcome from each trial. For the assessment of benefits, we summarised continuous data as standardised mean differences (SMDs) and dichotomous data as risk ratios (RRs). We used risk differences (RDs) for the assessment of adverse events. We used random-effects models for all statistical analyses. We used subgroup analysis to explore potential causes for heterogeneity (e.g. type of placebo) and sensitivity analyses to explore the robustness of the primary analyses (e.g. fixed-effect model).

MAIN RESULTS

We included 96 randomised trials (4200 participants), ranging from 8 to 393 participants in each trial. 83 trials (3614 participants) provided usable data. The trials included 15 different mental health disorders, the most common being anxiety (25 trials), depression (16 trials), and sleep-wake disorders (11 trials). All 96 trials were assessed as high risk of bias partly because of the inability to blind participants and personnel in trials with two control interventions. The quality of evidence was rated low to very low, mostly due to risk of bias, imprecision in estimates, and heterogeneity. Only one trial compared wait-list versus no-treatment directly but the authors were not able to provide us with any usable data on the comparison. Five trials compared usual care versus wait-list or no-treatment and found a SMD -0.33 (95% CI -0.83 to 0.16, I² = 86%, 523 participants) on benefits. The difference between all placebo interventions combined versus wait-list or no-treatment was SMD -0.37 (95% CI -0.49 to -0.25, I² = 41%, 65 trials, 2446 participants) on benefits. There was evidence of some asymmetry in the funnel plot (Egger's test P value of 0.087). Almost all the trials were small. Subgroup analysis found a moderate effect in favour of psychological placebos SMD -0.49 (95% CI -0.64 to -0.30; I² = 53%, 39 trials, 1656 participants). The effect of pharmacological placebos versus wait-list or no-treatment on benefits was SMD -0.14 (95% CI -0.39 to 0.11, 9 trials, 279 participants) and the effect of physical placebos was SMD -0.21 (95% CI -0.35 to -0.08, I² = 0%, 17 trials, 896 participants). We found large variations in effect sizes in the psychological and pharmacological placebo comparisons. For specific mental health disorders, we found significant differences in favour of all placebos for sleep-wake disorders, major depressive disorder, and anxiety disorders, but the analyses were imprecise due to sparse data. We found no significant differences in harms for any of the comparisons but the analyses suffered from sparse data. When using a fixed-effect model in a sensitivity analysis on the comparison for usual care versus wait-list and no-treatment, the results were significant with an SMD of -0.46 (95 % CI -0.64 to -0.28). We reported an alternative risk of bias model where we excluded the blinding domains seeing how issues with blinding may be seen as part of the review investigation itself. However, this did not markedly change the overall risk of bias profile as most of the trials still included one or more unclear bias domains.

AUTHORS' CONCLUSIONS

We found marked variations in effects between placebo versus no-treatment and wait-list and between subtypes of placebo with the same comparisons. Almost all the trials were small with considerable methodological and clinical variability in factors such as mental health population, contents of the included control interventions, and outcome domains. All trials were assessed as high risk of bias and the evidence quality was low to very low. When researchers decide to use placebos or usual care control interventions in trials with people with mental health disorders it will often lead to lower estimated effects of the experimental intervention than when using wait-list or no-treatment controls. The choice of a control intervention therefore has considerable impact on how effective a mental health treatment appears to be. Methodological guideline development is needed to reach a consensus on future standards for the design and reporting of control interventions in mental health intervention research.

Neck-specific strengthening exercise compared with placebo sham ultrasound in patients with migraine: a randomized controlled trial

BACKGROUND

Migraine patients have musculoskeletal disorders and pain in the cervical. And, despite the pathophysiology demonstrating the relationship between migraine and the cervical spine, the effectiveness of craniocervical exercises in these patients has not been verified. So, the aimed of this study was verify the effectiveness of craniocervical muscle-strengthening exercise (CMSE) in reducing the frequency and intensity of headache in migraine patients.  METHODS: A two-armed, parallel-group randomized controlled trial with a 3-month follow-up was performed. For eight weeks, the volunteers in the intervention group (n = 21) performed a protocol of CMSE, while those in the sham ultrasound group (n = 21) received the application of disconnected therapeutic ultrasound in the upper trapezius and guideline for home-stretching. The primary outcomes were the frequency and intensity of the headache. The secondary outcomes were questionnaires about migraine and neck disability, and satisfaction with the treatment, cervical range of motion, the pressure pain threshold, craniocervical flexion test (CCFT), cervical muscle strength and endurance test, and the cervical muscle activity during the physical tests.

RESULTS

No differences were observed for the changes observed in primary outcomes after eight weeks and at the 3-months follow up (p > 0.05). For the secondary outcomes, craniocervical exercises improved the sensitivity of the frontal muscle (p = 0.040) and promoted a reduced amplitude of muscle activity of the anterior scalene and upper trapezius in the last stages of CCFT (p ≤ 0.010). There was also reduced muscle activity of the anterior scalene and splenius capitis in the endurance test (p ≤ 0.045), as evaluated by surface electromyography.

CONCLUSION

CMSE were insufficient in reducing the frequency and intensity of headache, improving the performance of the cervical muscles, or reducing migraine and neck pain-related disabilities. This was found despite a decreased electromyographic activity of the cervical muscles during the last stages of CCFT and increased median frequency during the endurance test.

TRIAL REGISTRATION

Accession code RBR-8gfv5j , registered 28/11/2016 in the Registro Brasileiro de Ensaios Clínicos (ReBEC).

Effective Oriental Magic for Analgesia: Acupuncture

Pain is a kind of complex physiological and psychological symptom, which makes the person debilitated and uncomfortable. Some persistent pain is unbearable for the patients, reducing the quality of life and bringing considerable pressure to the individuals and society. Pain killers seem to be effective in analgesia for patients, but their safety and addiction are crucial issues. From the theory of traditional Chinese medicine (TCM), the blocked meridian is the main cause of pain, and effective acupuncture can play a positive analgesic effect. Acupuncture that can date back thousands of years is one of the ancient medical practices in China. Its safety and effectiveness are respected. Based on its superior safety and inferior side effects, it has been gradually recognized as a therapeutic intervention method for complementary medicine, which is also generally used to treat multiple pain diseases. It is shown by modern medical studies that neurotransmitters are the material basis for the acupuncture effect, and the effect of acupuncture analgesia is related to changes in neurotransmitters. However, the specific mechanism has not been elucidated. This review aims to comprehensively discuss the historical evolution of acupuncture analgesia, clinical research of acupuncture analgesia, comparison of acupuncture and drug therapy, the neurotransmitter mechanism of acupuncture analgesia, the effect of acupuncture manipulation on analgesia, and bibliometric analysis of acupuncture treatment for pain, to explore the superiority and related mechanism of acupuncture analgesia from different aspects, and to provide a more effective treatment for alleviating patients' pain.

Platelet-Rich Plasma Injection Associated With Microtenotomy in Lateral Epicondylitis – is a Tendon Tear Associated with the Therapeutic Response?

Objective

Ultrasound-guided platelet-rich plasma (PRP) injections, as well as needle tenotomy, are becoming increasingly popular in the treatment of epicondylitis. Whether ultrasound (US) findings predict the clinical benefit of these techniques is unclear at the moment. This study aimed to investigate the relationship between the presence of tendon tear assessed by US and the therapeutic response of the PRP injection following needle microtenotomy in patients with epicondylitis.

Methodology

This is a retrospective observational study. Twenty-six patients with chronic (>three months) lateral epicondylitis recalcitrant to conservative treatment or corticosteroid injection. Patients underwent US-guided microtenotomy followed by PRP injection. Data regarding gender, age, US findings at baseline, and numeric pain rating scale (NPRS) scores before and after intervention were collected. Pain improvement rates were calculated at several follow-up time points, namely one, three, six, and 12 months post-intervention. Results are stated as mean ± standard deviation.

Results

At the time of intervention, the mean age was 47.6±6.5 years, and 57.7% of patients were men. Overall, the mean initial NPRS score was 7.5±1.2, and there were no statistically significant differences in mean initial NPRS scores between the groups with or without tendon tear on the US imaging. The mean improvement rate at one, three, and six months was similar between patients with and without tendon tear. However, a statistically significant difference was observed at 12 months (73.1±37.6% vs. 16.0±21.9, p=0.029). 

Conclusions

Patients with tendon tear demonstrated a higher pain improvement rate at 12 months follow-up. This finding could predict the clinical response to this technique, thus allowing a better selection of the candidates.

High-Intensity Inspiratory Muscle Training Improves Scalene and Sternocleidomastoid Muscle Oxygenation Parameters in Patients With Weaning Difficulties: A Randomized Controlled Trial

Background

Critically ill patients who have difficulties weaning from the mechanical ventilator are prone to develop respiratory muscle weakness. Inspiratory muscle training (IMT) can improve respiratory muscle strength. Whether IMT can improve scalene and sternocleidomastoid muscle oxygenation parameters is unknown.

Aim

To compare changes in muscle oxygenation parameters of scalene and sternocleidomastoid inspiratory muscles during a standardized task between patients with weaning difficulties who received either high-intensity IMT (intervention) or sham low-intensity IMT (control).

Method

Forty-one patients performed daily IMT sessions (4 sets, 6–10 breaths) until weaning success or for 28 consecutive days. The training load was progressively adjusted in the intervention group (n = 22) to the highest tolerable load, whilst the control group (n = 19) kept training at 10% of their baseline maximal inspiratory pressure (PImax). Breathing characteristics (i.e., work and power of breathing, PoB), respiratory muscle function [i.e., PImax and forced vital capacity (FVC)] were measured during a standardized loaded breathing task against a load of 30% of baseline PImax before and after the IMT period. In addition, during the same loaded breathing task, absolute mean and nadir changes from baseline in local scalene and sternocleidomastoid muscle oxygen saturation index (Δ%StiO2) (an index of oxygen extraction) and nadir Δ%StiO2 normalized for the PoB were measured by near-infrared spectroscopy.

Results

At post measures, only the intervention group improved mean PoB compared to pre measures (Pre: 0.42 ± 0.33 watts, Post: 0.63 ± 0.51watts, p-value &lt; 0.01). At post measures, both groups significantly improved nadir scalene muscles StiO2% normalized for the mean PoB (ΔStiOnadir%/watt) compared to pre measurements and the improvement was not significant different between groups (p-value = 0.40). However, at post measures, nadir sternocleidomastoid muscle StiO2% normalized for the mean PoB (ΔStiOnadir%/watt) was significantly greater improved in the intervention group (mean difference: +18.4, 95%CI: −1.4; 38.1) compared to the control group (mean difference: +3.7, 95%CI: −18.7; 26.0, between group p-value &lt; 0.01). Both groups significantly improved PImax (Intervention: +15 ± 13 cmH2O p-value &lt; 0.01, Control: +13 ± 15 cmH2O p-value &lt; 0.01). FVC only significantly improved in the intervention group (+0.33 ± 0.31 L p &lt; 0.01) report also change in control group.

Conclusion

This exploratory study suggests that high-intensity IMT induces greater improvements in scalene and sternocleidomastoid muscle oxygenation parameters attributed for oxygen delivery, utilization and oxygen saturation index compared to low-intensity IMT in patients with weaning difficulties.

The Effects and Safety of Chinese Herbal Medicine on Blood Lipid Profiles in Placebo-Controlled Weight-Loss Trials: A Systematic Review and Meta-Analysis

This study was conducted to assess the effects and safety of Chinese herbal medicine (CHM) on blood lipids among adults with overweight or obesity. Fourteen bibliographic databases were comprehensively searched, from their respective inceptions up to April 2021, for randomised placebo-controlled weight-loss trials using CHM formulation on total cholesterol, triglycerides, LDL cholesterol, and HDL cholesterol over ≥4 weeks. Data collection, risk of bias assessment, and statistical analyses were guided by the Cochrane Handbook (v6.1). Continuous outcomes were expressed as the mean difference with 95% confidence intervals, and categorical outcomes were expressed as a risk ratio with 95% confidence intervals. All analyses were two-tailed with a statistical significance of p < 0.05. Fifteen eligible studies with 1,533 participants were included in this meta-analysis. Findings from meta-analyses indicated that CHM interventions, compared to placebo, reduced triglyceride (MD −0.21 mmol/L, 95% CI −0.41 to −0.02, I² = 81%) and increased HDL cholesterol (MD 0.16 mmol/L, 95% CI 0.04 to 0.27, I² = 94%) over a median of 12 weeks. The reduction in total cholesterol and LDL cholesterol were not statistically significant. Furthermore, the tendency of reduced triglycerides was identified among overweight participants with high baseline triglycerides. Attrition rates and frequency of adverse events were indifferent between the two groups. CHM may provide lipid-modulating benefits on triglycerides and HDL cholesterol among participants with overweight/obesity, with the tendency for significant triglyceride reduction observed among overweight participants with high baseline triglycerides. However, rigorously conducted randomised controlled trials with larger sample sizes are required to validate these findings.

Using Artificial Intelligence-based Methods to Address the Placebo Response in Clinical Trials

The placebo response is a highly complex psychosocial-biological phenomenon that has challenged drug development for decades, particularly in neurological and psychiatric disease. While decades of research have aimed to understand clinical trial factors that contribute to the placebo response, a comprehensive solution to manage the placebo response in drug development has yet to emerge. Advanced data analytic techniques, such as artificial intelligence (AI), might be needed to take the next leap forward in mitigating the negative consequences of high placebo-response rates. The objective of this review was to explore the use of techniques such as AI and the sub-discipline of machine learning (ML) to address placebo response in practical ways that can positively impact drug development. This examination focused on the critical factors that should be considered in applying AI and ML to the placebo response issue, examples of how these techniques can be used, and the regulatory considerations for integrating these approaches into clinical trials.

Randomised controlled trial of an accommodative support lens designed for computer users

PURPOSE

Accommodative support (AS) lenses are a low add progressive addition spectacle lens designed to ease symptoms in computer vision syndrome (CVS). The study aims to investigate if (1) AS lenses improve CVS symptoms; (2) binocular/accommodative functions predict a benefit from AS lenses and (3) wearing AS lenses for six months impacts on binocular/accommodative functions.

METHODS

Pre-presbyopic adults with symptoms of CVS (Computer Vision Syndrome Questionnaire, CVS-Q^© , score ≥ 6) were randomly allocated to wear AS lenses or control single vision (SV) lenses. The CVS-Q^© and a battery of optometric tests were applied at baseline and after three and six months. Participants and researchers were masked to participant group. After six months, the SV group were unmasked and changed to AS lenses and one week later asked to choose which they preferred.

RESULTS

The change in CVS-Q^© scores from baseline to six months did not differ significantly in the two groups. At the end of the one week period, when the control group wore the AS lenses, control group participants were significantly more likely to prefer AS lenses to SV lenses. No optometric functions correlated with the benefit from AS lenses. AS lenses did not have any adverse effects on binocular or accommodative function.

CONCLUSIONS

In pre-presbyopic adults, there was no greater improvement in CVS-Q^© scores in the group wearing AS lenses than in the control group. No adverse effects on optometric function (including accommodation) are associated with wearing AS lenses.

Role of hyperpolarization-activated cyclic nucleotide-gated ion channels in neuropathic pain: a proof-of-concept study of ivabradine in patients with chronic peripheral neuropathic pain

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channel receptors mediate neuropathic pain in preclinical models. Here, exploratory analysis reveals a dose-dependent reduction in pain with HCN blockade in patients with neuropathic pain.

Introduction:

Hyperpolarization-activated cyclic nucleotide-gated (HCN) ion channels mediate repetitive action potential firing in the heart and nervous system. The HCN2 isoform is expressed in nociceptors, and preclinical studies suggest a critical role in neuropathic pain. Ivabradine is a nonselective HCN blocker currently available for prescription for cardiac indications. Mouse data suggest that ivabradine in high concentrations is equianalgesic with gabapentin. We sought to translate these findings to patients with chronic peripheral neuropathic pain.

Objectives:

We sought to translate these findings to patients with chronic peripheral neuropathic pain.

Methods:

We adopted an open-label design, administering increasing doses of ivabradine to target a heart rate of 50 to 60 BPM, up to a maximum of 7.5 mg twice daily. All participants scored their pain on an 11-point numerical rating scale (NRS).

Results:

Seven (7) participants received the drug and completed the study. There was no significant treatment effect on the primary endpoint, the difference between the mean score at baseline and at maximum dosing (mean reduction = 0.878, 95% CI = −2.07 to 0.31, P = 0.1). Exploratory analysis using linear mixed models, however, revealed a highly significant correlation between ivabradine dose and pain scores (χ²(1) = 74.6, P < 0.001), with a reduction of 0.12 ± 0.01 (SEM) NRS points per milligram. The 2 participants with painful diabetic neuropathy responded particularly well.

Conclusion:

This suggests that ivabradine may be efficacious at higher doses, particularly in patients with diabetic neuropathic pain. Importantly, participants reported no adverse effects. These data suggest that ivabradine, a peripherally restricted drug (devoid of central nervous system side effects), is well tolerated in patients with chronic neuropathic pain. Ivabradine is now off-patent, and its analgesic potential merits further investigation in clinical trials.

Patients' attitude towards a sham-controlled trial on pulmonary vein isolation in atrial fibrillation

Background

The interpretation of recent trials on pulmonary vein ablation (PVI) for the treatment of atrial fibrillation (AF) is hampered by the lack of blinding and sham controls. The feasibility of a sham-controlled trial has been questioned. We aimed to assess the attitude of potential participants regarding a sham-controlled trial in a common AF-patient population planned for PVI.

Methods

Patients in two tertiary care centres planned for PVI were asked for their current AF symptoms using the Atrial Fibrillation Effect on QualiTy of Life (AFEQT) questionnaire 1 day before catheter ablation. Subsequently, the study design of a hypothetical sham-controlled PVI-study was introduced, and patients were asked for their agreement in participation. Telephone follow-up of the AFEQT questionnaire was conducted 3 months after PVI.

Results

One hundred and ninety-six patients (mean age 64 ± 11 years, 63% male) were included. Seventy-nine (40%) patients expressed their agreement to participate in the hypothetical sham-controlled trial. An additional 7% agreed to participate if a cross-over option after three months was offered. Agreement rate was similar in patients with first and Redo-PVI and minimal, moderate or severe symptoms. Mean overall AFEQT at baseline was 55 ± 19 and improved by 25 ± 20 points after 3 months (p < 0.001 versus baseline).

Conclusion

With a participation rate of 40% in potential study participants, a sham-controlled trial for pulmonary vein isolation seems feasible. Patient-reported symptom relief after pulmonary vein isolation is in accordance with previous randomized open studies. The benefit of PVI should be rigorously evaluated in a sham-controlled trial.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00392-021-01959-z.

Cutoff criteria for the placebo response: a cluster and machine learning analysis of placebo analgesia

Computations of placebo effects are essential in randomized controlled trials (RCTs) for separating the specific effects of treatments from unspecific effects associated with the therapeutic intervention. Thus, the identification of placebo responders is important for testing the efficacy of treatments and drugs. The present study uses data from an experimental study on placebo analgesia to suggest a statistical procedure to separate placebo responders from nonresponders and suggests cutoff values for when responses to placebo treatment are large enough to be separated from reported symptom changes in a no-treatment condition. Unsupervised cluster analysis was used to classify responders and nonresponders, and logistic regression implemented in machine learning was used to obtain cutoff values for placebo analgesic responses. The results showed that placebo responders can be statistically separated from nonresponders by cluster analysis and machine learning classification, and this procedure is potentially useful in other fields for the identification of responders to a treatment.