Placebo effect in the treatment of duodenal ulcer

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).

A Dose of Reality About Dose-Response Relationships

Observational research can be strengthened by examining potential dose-response relationships that correlate a clinical intervention with a patient outcome. Despite being a classic criterion for establishing causality, dose-response testing can be difficult to interpret in clinical medicine due to multiple diverse pitfalls. This review introduces a cautionary framework for investigators considering dose-response relationships in observational research to support evidence-based medicine. Each pitfall is illustrated with a specific example relevant when analyzing a dose-response relationship. Several pitfalls stem from faulty interpretation including confounding by indication and fallible range selection. Additional pitfalls relate to improper analysis including fitting a nonlinear model and misclassification error. Further pitfalls arise in special situations including subjective self-report and artifacts from survival bias. These caveats are common sources of misunderstanding in analyses that examine the link between varying exposures and the intensity of clinical outcomes. Awareness of specific pitfalls, we suggest, might help advance the conduct, application, and translation of dose-response relationships in observational research to inform evidence-based medical care.

Effects of sham acupuncture for chronic musculoskeletal pain syndrome: A systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Acupuncture has been widely used for chronic musculoskeletal pain syndrome (MPS). Due to the strong influence of sham acupuncture (SA) in clinical trials, the treatment of MPS by acupuncture remains controversial. Different types of SA procedures might produce different responses. The purpose of this systematic review was to assess the effect of SA on MPS.

METHODS

We searched 8 literature databases for randomized controlled trials (RCTs) on acupuncture for chronic MPS with SA as a control from database inception to November 29, 2022. SA included superficial acupuncture on non-acupoints (SANAs), non-penetration on acupoints (NPAs), and non-penetration on non-acupoints (NPNAs). Two independent reviewers assessed the risk of bias and conducted the research selection, data extraction, and quality assessment of the included RCTs. We conducted data analysis using the RevMan 5.3 and STATA 14 software packages, and traditional meta-analysis was adopted for direct comparison. A network meta-analysis (NMA) was executed using frequency models in which we combined all available direct and indirect evidence from RCTs. The pain-related indicators were set as primary outcomes, and GRADEpro online was implemented for the assessment of evidence quality.

RESULTS

Forty-two RCTs were included in this study, encompassing a total of 6876 patients and incorporating 3 types of SA procedures. In our traditional meta-analysis, true acupuncture (TA) was more effective than SANAs, NPAs, and NPANAs concerning MPS. In the NMA, TA was the most effective modality, followed by SANAs, NPAs and NPANAs, and then the blank control (BC). In this NMA and according to the therapeutic effects in the pain indicators, the rankings of SA were as follows: SANA (surface under the cumulative ranking curve [SUCRA], 65.3%), NPA (SUCRA, 46.2%), and NPANA (SUCRA, 34.2%). The quality of the evidence for outcomes ranged from "low" to "moderate."

CONCLUSIONS

Compared with SA, TA was effective in treating MPS. The effects produced by different SA procedures were different, and the order of effects from greatest to least was as follows: SANA, NPA, and NPANA.

Replication crisis and placebo studies: rebooting the bioethical debate

A growing body of cross-cultural survey research shows high percentages of clinicians report using placebos in clinical settings. One motivation for clinicians using placebos is to help patients by capitalising on the placebo effect's reported health benefits. This is not surprising, given that placebo studies are burgeoning, with increasing calls by researchers to ethically harness placebo effects among patients. These calls propose placebos/placebo effects offer clinically significant benefits to patients. In this paper, we argue many findings in this highly cited and 'hot' field have not been independently replicated. Evaluating the ethicality of placebo use in clinical practice involves first understanding whether placebos are efficacious clinically. Therefore, it is crucial to consider placebo research in the context of the replication crisis and what can be learnt to advance evidence-based knowledge of placebos/placebo effects and their clinical relevance (or lack thereof). In doing so, our goal in this paper is to motivate both increased awareness of replication issues and to help pave the way for advances in scientific research in the field of placebo studies to better inform ethical evidence-based practice. We argue that, only by developing a rigorous evidence base can we better understand how, if at all, placebos/placebo effects can be harnessed ethically in clinical settings.

Safety and efficacy of zilucoplan in patients with generalised myasthenia gravis (RAISE): a randomised, double-blind, placebo-controlled, phase 3 study

BACKGROUND

Generalised myasthenia gravis is a chronic, unpredictable, and debilitating rare disease, often accompanied by high treatment burden and with an unmet need for more efficacious and well tolerated treatments. Zilucoplan is a subcutaneous, self-administered macrocyclic peptide complement C5 inhibitor. We aimed to assess safety, efficacy, and tolerability of zilucoplan in patients with acetylcholine receptor autoantibody (AChR)-positive generalised myasthenia gravis.

METHODS

RAISE was a randomised, double-blind, placebo-controlled, phase 3 trial that was done at 75 sites in Europe, Japan, and North America. We enrolled patients (aged 18-74 years) with AChR-positive generalised myasthenia gravis (Myasthenia Gravis Foundation of America disease class II-IV), a myasthenia gravis activities of daily living (MG-ADL) score of least 6, and a quantitative myasthenia gravis score of at least 12. Participants were randomly assigned (1:1) to receive subcutaneous zilucoplan 0·3 mg/kg once daily by self-injection, or matched placebo, for 12 weeks. The primary efficacy endpoint was change from baseline to week 12 in MG-ADL score in the modified intention-to-treat population (all randomly assigned patients who received at least one dose of study drug and had at least one post-dosing MG-ADL score). Safety was mainly assessed by the incidence of treatment-emergent adverse events (TEAEs) in all patients who had received at least one dose of zilucoplan or placebo. This trial is registered at ClinicalTrials.gov, NCT04115293. An open-label extension study is ongoing (NCT04225871).

FINDINGS

Between Sept 17, 2019, and Sept 10, 2021, 239 patients were screened for the study, of whom 174 (73%) were eligible. 86 (49%) patients were randomly assigned to zilucoplan 0·3 mg/kg and 88 (51%) were assigned to placebo. Patients assigned to zilucoplan showed a greater reduction in MG-ADL score from baseline to week 12, compared with those assigned to placebo (least squares mean change -4·39 [95% CI -5·28 to -3·50] vs -2·30 [-3·17 to -1·43]; least squares mean difference -2·09 [-3·24 to -0·95]; p=0·0004). TEAEs occurred in 66 (77%) patients in the zilucoplan group and in 62 (70%) patients in the placebo group. The most common TEAE was injection-site bruising (n=14 [16%] in the zilucoplan group and n=8 [9%] in the placebo group). Incidences of serious TEAEs and serious infections were similar in both groups. One patient died in each group; neither death (COVID-19 [zilucoplan] and cerebral haemorrhage [placebo]) was considered related to the study drug.

INTERPRETATION

Zilucoplan treatment showed rapid and clinically meaningful improvements in myasthenia gravis-specific efficacy outcomes, had a favourable safety profile, and was well tolerated, with no major safety findings. Zilucoplan is a new potential treatment option for a broad population of patients with AChR-positive generalised myasthenia gravis. The long-term safety and efficacy of zilucoplan is being assessed in an ongoing open-label extension study.

FUNDING

UCB Pharma.

Does the placebo effect on hot flashes depend on the placebo dose?

PURPOSE

To investigate the presence of a placebo dose-response effect in four randomized, double-blind, placebo-controlled, multi-dose hot flash clinical trials conducted at Mayo Clinic.

METHODS

Hot flash score, frequency, and hot flash-related distress for each placebo dose level were summarized at each time point by mean and standard deviation and changes from baseline were plotted to visualize a possible placebo dose-effect response. Furthermore, a meta-analysis was conducted for each endpoint in the highest and lowest dosage arms across the four trials.

RESULTS

Longitudinal plots of mean hot flash scores, frequencies, and hot flash-related distress scores in patients taking placebo in each study showed a decline in hot flash scores over time without any clinically meaningful differences between the lowest and highest dosage arms in each study. The meta-analysis for each endpoint in the highest and lowest dosage arms across the four trials revealed no clinically important differences either.

CONCLUSION

While the current study cannot rule out the existence of a placebo dose-response effect in multi-dose placebo-controlled trials in patients with hot flashes or other conditions, it suggests, along with the available data in the placebo literature, that, at least in well-conducted multi-dose clinical trials in which the placebo was used as control, such an effect, if it exists at all, should be very small. Therefore, pooling data from different placebo subgroups is unlikely to compromise the validity of comparisons between the combined placebo arms and each treatment arm.

TIDieR-Placebo: A guide and checklist for reporting placebo and sham controls

BACKGROUND

Placebo or sham controls are the standard against which the benefits and harms of many active interventions are measured. Whilst the components and the method of their delivery have been shown to affect study outcomes, placebo and sham controls are rarely reported and often not matched to those of the active comparator. This can influence how beneficial or harmful the active intervention appears to be. Without adequate descriptions of placebo or sham controls, it is difficult to interpret results about the benefits and harms of active interventions within placebo-controlled trials. To overcome this problem, we developed a checklist and guide for reporting placebo or sham interventions.

METHODS AND FINDINGS

We developed an initial list of items for the checklist by surveying experts in placebo research (n = 14). Because of the diverse contexts in which placebo or sham treatments are used in clinical research, we consulted experts in trials of drugs, surgery, physiotherapy, acupuncture, and psychological interventions. We then used a multistage online Delphi process with 53 participants to determine which items were deemed to be essential. We next convened a group of experts and stakeholders (n = 16). Our main output was a modification of the existing Template for Intervention Description and Replication (TIDieR) checklist; this allows the key features of both active interventions and placebo or sham controls to be concisely summarised by researchers. The main differences between TIDieR-Placebo and the original TIDieR are the explicit requirement to describe the setting (i.e., features of the physical environment that go beyond geographic location), the need to report whether blinding was successful (when this was measured), and the need to present the description of placebo components alongside those of the active comparator.

CONCLUSIONS

We encourage TIDieR-Placebo to be used alongside TIDieR to assist the reporting of placebo or sham components and the trials in which they are used.

Determinants of placebo effects

Determinants of placebo effects and placebo response can be considered from multiple intrinsic and extrinsic perspectives. Intrinsic factors may influence the patient and the clinician/researcher. Patient expectations and previous experiences are considered two of the major intrinsic determinants of placebo response. Other patient determinants include the neural systems under treatment/study, situational factors and reactions to the environment, and personality traits. Clinician/researcher determinants of placebo response include personality factors such as empathy, perceived expertise, the clinical relationship with the patient, and the clinician's belief in the efficacy of the treatment. Extrinsic determinants include the type of study design, influence of advertising or branding, and forces expressed by the cultural milieu. These determinants do not act in isolation, but rather form a complex interaction that ultimately impacts the promotion or deterrence of the placebo effect in clinical and research settings.

Prescribing Placebos: An Experimental Examination of the Role of Dose, Expectancies, and Adherence in Open-Label Placebo Effects

Background

Recent evidence indicates that placebo effects can occur even when patients know that they are taking a placebo, termed the open-label placebo effect.

Aim

To assess whether placebo dose (one pill per day vs. four pills per day), treatment expectancies, and adherence contribute to open-label placebo effects.

Method

Healthy undergraduate participants were randomly assigned to take one or four open-label placebo pills per day or to a no-treatment control group. Placebo-treated participants took a 5-day course of an open-label placebo described as enhancing physical (symptoms and sleep) and psychological (positive and negative emotional experience) well-being. Expectancies about placebo effectiveness and well-being were assessed at baseline, and well-being and adherence were assessed after the 5-day course of treatment.

Results

Medium-to-large open-label placebo effects were evidenced in all well-being outcomes including sleep quality. Dose did not influence these effects. Both treatment expectancies and adherence were significant independent predictors of enhanced well-being in the two psychological well-being outcomes and the experience of physical symptoms, but sleep quality improved independently.

Conclusions

This is the first study to demonstrate the effect of open-label placebos in improving well-being and sleep quality and to show that open-label placebo reposes do not appear to be dose-dependent, but for most well-being outcomes are independently predicted by both positive expectancies and treatment adherence.

Placebo Responses and Placebo Effects in Functional Gastrointestinal Disorders

Much has been written about the placebo effects in functional gastrointestinal disorders (FGD), especially in irritable bowel syndrome (IBS), driven by the early hypothesis that in randomized controlled trials (RCTs) of IBS, the placebo effect might be specifically high and thus, corrupts the efficacy of novel drugs developed for this condition. This narrative review is based on a specific search method, a database (www.jips.online) developed since 2004 containing more than 4,500 papers (data papers, meta-analyses, systematic reviews, reviews) pertinent to the topic placebo effects/placebo response. Three central questions-deducted from the body of current literature-are addressed to explore the evidence behind this hypothesis: What is the size placebo effect in FGD, especially in IBS, and is it different from the placebo effect seen in other gastrointestinal disorders? Is the placebo effect in FGD different from other functional, non-intestinal disorders, e.g. in other pain syndromes? Is the placebo effect in FGD related to placebo effects seen in psychiatry, e.g. in depression, anxiety disorders, and alike? Following this discussion, a fourth question is raised as the result of the three: What are the consequences of this for future drug trials in FGD? In summary it is concluded that, contrary to common belief and discussion, the placebo effect seen in RCT in FGD is not specifically high and extraordinary as compared to other comparable (i.e. functional) disorders. It shares less than expected commonalities with the placebo effect in psychiatry, and very few predictors have yet been identified that determine its effect size, especially some that are driven by design features of the studies. Current practice of RCT in IBS seems to limit and control the placebo effect quite well, and future trial practice, e.g. head-to-head trial, still offers options to maintain this control, even in the absence of placebos used.

Quantitative analysis of the placebo response in pharmacotherapy of insomnia and its application in clinical trials

Study Objectives

This study aimed to develop a robust placebo response model for the pharmacotherapy for insomnia to guide drug development and clinical practice.

Methods

PubMed, EMBASE, and Cochrane Library databases were systematically searched for randomized placebo-controlled trials of medications for insomnia dating from the inception dates of the databases to April 18, 2018. Three placebo response models were established to describe the time–course of sleep parameters measured by objective (polysomnography or actigraphy) or subjective methods (sleep diary or questionnaires). The established models were applied to simulate placebo response distribution under different conditions using Monte Carlo simulations.

Results

Fifty-four studies involving 6,416 subjects were included. Placebo response increased over time and reached a plateau at approximately 8 weeks from start of therapy. Established models described the observed data reasonably well based on various diagnostic plots. Baseline sleep parameters affected the placebo response. There were significant positive correlations with placebo response and the severity of sleep latency, wake after sleep onset, and total sleep time at baseline. In addition, placebo response, assessed by subjective and objective methods, was consistent after correcting the baseline levels.

Conclusions

The established placebo response models can serve as a tool to predict placebo response at different baseline levels, which can provide valuable reference for clinical trial design, decision-making in drug development, and clinical practice.

Open-label Placebos for Wound Healing: A Randomized Controlled Trial

Background

Open-label placebos are a novel treatment option, in which participants take placebos with full knowledge that they do not contain active medicine. Open-label placebo treatments have been shown to result in patient-reported symptom improvements, but they have not been tested on objectively measurable physiological outcomes such as wound healing.

Purpose

The current study aimed to determine whether open-label placebos improved wound healing in punch biopsy wounds compared with no treatment.

Methods

In a randomized controlled trial, 70 participants (mean age 27.6 ± 10.1, 58 female) were provided with information about the beneficial effects of placebos and given a 4 mm punch biopsy wound. Participants were then randomized to either an open-label placebo intervention (two placebo tablets twice a day for 10 days) or a no-treatment control group. Wounds were photographed at 7 days and 10 days to determine reepithelialization of the wound surface.

Results

No significant differences were observed between the open-label placebo and control conditions in the percentage of wound area healed or for the number of participants with fully reepithelialized wounds at 7 days (placebo 7/32 wounds healed, control 10/33 wounds healed, (χ2[1, N = 65] = 0.60, p = .440, φ = 0.10) and 10 days after wounding (placebo 17/32, control 25/33 wounds healed (χ2[1, N = 65] = 3.64, p = .056, φ = 0.24).

Conclusions

Open-label placebo treatment does not improve the healing rate of wounds. Open-label placebos may be beneficial for subjective patient-reported outcomes but do not influence wound healing.

Australian New Zealand Clinical Trials Registration

ACTRN12616000411448.

Placebos as a Source of Agency: Evidence and Implications

Bioethical discussions surrounding the use of placebos in clinical practice have long revolved around the moral permissibility of deceiving a patient if it is likely to benefit them. While these discussions have been insightful and productive, they reinforce the notion that placebo effects can only be induced through deception. This paper challenges this notion, looking beyond the paradigmatic clinical encounter involving deceptive placebos and towards many other routes that bring about placebo effects. After briefly describing the bioethical terrain surrounding the deceptive use of placebos in clinical practice, section 1 offers an examination of the various mechanisms known to contribute to placebo effects: classical conditioning, expectations, affective pathways, open-label placebo treatments, and additional factors that do not fall easily into a single category. The following section explores how each of these routes can be harnessed to bring about clinical benefits without the use of deception. This provides grounding for reconceiving of the placebo effect as a clinical tool that is not always in conflict with patient autonomy and can even be seen as a source of agency. In the final section, implications of the shift away from seeing placebos as necessarily deceptive are discussed. These include the necessity of looking beyond the clinical encounter and mainstream medicine as the primary sites of placebo responses, how important acknowledging the limits of placebo effects will be when we do so, as well as the difficulties of disentangling agency, responsibility, and blame within medicine.

The Myth of the Placebo Response

The placebo response is a myth. It does not exist in reality, and continuing to name it is hindering the optimal application of science to healing in medicine. On the surface, it is obvious that, when defined as a biological response to an inert pill (like a sugar pill), the idea of a "response" to a placebo is impossible. Inert treatments by definition do not produce responses. So why do we continue to ponder why people get better from taking inert substances and base our acceptance of legitimate treatments on demonstrating that they go beyond that response? The problem arises because we have flawed assumptions of the value that reductionistic science and the demonstration of specific effects has for healing. To support those flawed assumptions, we support the idea of "the placebo response." This causes confusion among patients, clinicians, regulators, and even scientists. Legitimate medical treatments have become defined as those that do more than produce a placebo response. An entire pharmaceutical industry and its regulators attempt to control and profit by proving that small molecules produce a clinical effect greater than the placebo response. Billions of dollars are made when that is proven, often even when the size of the response in the active over the placebo group is miniscule. The fact is people heal and that inherent healing capacity is both powerful and influenced by mental, social, and contextual factors that are embedded in every medical encounter since the idea of treatment began. In this chapter, I argue that our understanding of healing and ability to enhance it will be accelerated if we stop using the term "placebo response" and call it what it is-the meaning response, and its special application in medicine called the healing response.

Are Blue Pills Better Than Green? How Treatment Features Modulate Placebo Effects

Treatment-related expectations are important predictors for placebo effects in various medical conditions. They are formed by verbal and nonverbal cues during the administration of treatments, such as verbal suggestions, conscious and unconscious associations with previous treatments, characteristics of patients and health-care providers as well as perceptual characteristics of the treatment. This review provides an overview of studies that aimed to elucidate the impact of treatment characteristics on expectations and placebo effects. Results show that high price, brand label, the use of invasive placebos and high placebo dose increase the expectations toward the beneficial effect of a placebo treatment, which in turn boost the placebo effect. Neuroimaging studies provide first insights into the neurobiological mechanisms underlying these differential placebo effects.

Administration of the Tablet Formulation of Olaparib in Patients with Ovarian Cancer: Practical Guidance and Expectations

Olaparib is a poly(ADP-ribose) polymerase enzyme inhibitor that is approved for use in patients with advanced ovarian cancer (OC) and genetic BRCA1/2 mutations who have received three or more prior lines of chemotherapy for maintenance treatment of recurrent OC that is in response to platinum-based chemotherapy regardless of BRCA mutation status and for human epidermal growth receptor factor 2-negative metastatic breast cancer with deleterious or suspected deleterious germline BRCA mutations who have previously been treated with chemotherapy in the neoadjuvant, adjuvant, or metastatic setting. Because olaparib is poorly soluble and requires advanced drug delivery techniques to ensure bioavailability, the originally approved 400 mg dose is taken as eight 50 mg capsules twice daily. An alternative melt-extrusion tablet formulation was developed to improve the pharmacokinetic and pharmacodynamic profile of olaparib and reduce the pill burden for patients. The recommended tablet dose is 300 mg twice daily (two 150 mg tablets). Phase III studies with the tablet formulation are ongoing for multiple tumor types. Two studies conducted with the olaparib tablet formulation have reported results: one in platinum-sensitive, BRCA-mutated recurrent OC (SOLO-2) and one that included patients with germline BRCA-mutated metastatic breast cancer (OlympiAD). The tablet is the approved formulation based on the SOLO-2 trial results. Because the capsule and tablet formulations have different bioavailability, physicians must strictly adhere to the dosing instructions provided in the prescribing information. The tablet offers greater convenience for most patients, especially when using olaparib for maintenance therapy. This review discusses the differences between the two formulations, dose determination, and guidance for use of olaparib tablets by patients with OC. Prior to implementing any changes in therapy, health care providers should engage their patients in discussion to support an informed transition between the formulations.

IMPLICATIONS FOR PRACTICE

Olaparib has recently been approved for maintenance treatment of recurrent ovarian cancer (OC) that is in response to platinum-based chemotherapy. The originally approved capsule formulation was dosed as 400 mg twice daily (eight 50 mg capsules). The recommended olaparib tablet dose is 300 mg twice daily (two 150 mg tablets). The tablet is the new approved formulation based on the SOLO-2 trial results. Because the capsule and tablet formulations have different bioavailability, physicians must strictly adhere to the dosing instructions provided in the prescribing information. The tablet offers greater convenience for most patients, especially when using olaparib for maintenance therapy. This review discusses the differences between the two formulations, dose determination, and guidance for use of olaparib tablets by patients with OC.

The effect of solifenacin on postvoid dribbling in women: results of a randomized, double-blind placebo-controlled trial

INTRODUCTION AND HYPOTHESIS

To determine the effectiveness of the muscarinic receptor antagonist solifenacin (VESIcare®) in the treatment of postvoid dribbling (PVD).

METHODS

We carried out a multicenter, 12-week, double-blind, randomized, placebo-controlled, parallel design study. Between 2012 and 2015, a total of 118 women (age 18-89 years) with PVD at least twice/weekly, were randomized to receive solifenacin (5 mg; n = 58) or placebo (n = 60) once daily. The primary outcome was the percentage reduction in PVD episodes. Secondary outcomes included the percentage of patients with ≥50% reduction in PVD episodes and changes in quality of life.

RESULTS

There were no differences in either the primary or secondary outcome variables. Subgroup analysis, based on those with more severe disease (>10 PVD episodes/week), showed a greater and significant percentage reduction in the frequency of PVD episodes per day (60.3% vs 32.1%; p = 0.035) and a higher percentage of patients showing ≥50% reduction in the frequency of PVD episodes with solifenacin (68.1% vs 45.8%; p = 0.0476). A significant solifenacin effect occurred at week 2 and continued through week 12 for the subgroup. For solifenacin, PVD reduction was the same for the entire cohort and subgroup, whereas for placebo, it was 10% lower in the subgroup, declining from 42% to 32%.

CONCLUSION

There were no differences in PVD outcomes between the solifenacin and placebo groups. Solifenacin may play a role in treating women with the most severe symptoms. Because of the powerful placebo response seen in this study, behavior-based interventions may be useful for treating PVD.

Efficacy and Safety of Selexipag in Adults With Raynaud's Phenomenon Secondary to Systemic Sclerosis: A Randomized, Placebo-Controlled, Phase II Study

Objective

To determine the effect of selexipag, an oral, selective IP prostacyclin receptor agonist, on the frequency of attacks of Raynaud's phenomenon (RP) in patients with systemic sclerosis (SSc).

Methods

Patients with SSc‐related RP were randomized 1:1 to placebo (n = 38) or selexipag (n = 36) in individualized doses (maximum of 1,600 μg twice daily) during a 3‐week titration period. The primary end point was the weekly average number of RP attacks during the study maintenance period, analyzed using a Bayesian approach with a negative binomial model adjusted for baseline number of RP attacks. Other outcome measures included Raynaud's Condition Score (RCS), RP attack duration, and treatment‐emergent adverse events (AEs).

Results

Baseline characteristics were comparable between treatment groups. For 83.3% of patients, the individualized maintenance dosage of selexipag was ≤800 μg twice daily. No significant difference was observed between placebo and selexipag in weekly average number of electronic diary (eDiary)–recorded RP attacks during the maintenance period (14.2 attacks during the maintenance period and 21.5 attacks during the baseline week in the placebo group [n = 32] versus 18.0 attacks during the maintenance period and 22.4 attacks during the baseline week in the selexipag group [n = 27]; adjusted mean treatment difference of 3.4 in favor of placebo). No significant treatment effect was observed on RCS or RP attack duration. In the double‐blind period, 86.8% of placebo‐treated patients and 100% of selexipag‐treated patients reported ≥1 AE; 55.3% and 91.7%, respectively, reported ≥1 prostacyclin‐associated AE.

Conclusion

Treatment with selexipag did not reduce the number of RP attacks compared with placebo. The safety profile of selexipag was similar to that previously reported. This study provides important information about the feasibility of eDiary reporting of RP attacks in clinical trials.

What trial participants need to be told about placebo effects to give informed consent: a survey to establish existing knowledge among patients with back pain

INTRODUCTION

Patients require an accurate knowledge about placebos and their possible effects to ensure consent for placebo-controlled clinical trials is adequately informed. However, few previous studies have explored patients' baseline (ie, pretrial recruitment) levels of understanding and knowledge about placebos. The present online survey aimed to assess knowledge about placebos among patients with a history of back pain.

DESIGN

A 15-item questionnaire was constructed to measure knowledge about placebos. Additional questions assessed sociodemographic characteristics, duration and severity of back pain, and previous experience of receiving placebos.

SETTING

Participants recruited from community settings completed the study online.

RESULTS

210 participants completed the questionnaire. 86.7% had back pain in the past 6 months, 44.3% currently had back pain. 4.3% had received a placebo intervention as part of a clinical trial and 68.1% had previously read or heard information about placebos. Overall knowledge of placebos was high, with participants on average answering 12.07 of 15 questions about placebos correctly (SD=2.35). However, few participants correctly answered questions about the nocebo effect (31.9% correct) and the impact of the colour of a placebo pill (55.2% correct).

CONCLUSIONS

The findings identified key gaps in knowledge about placebos. The lack of understanding of the nocebo effect in particular has implications for the informed consent of trial participants. Research ethics committees and investigators should prioritise amending informed consent procedures to incorporate the fact that participants in the placebo arm might experience adverse side effects.

The Placebo Response in Pediatric Abdominal Pain-Related Functional Gastrointestinal Disorders: A Systematic Review and Meta-Analysis

OBJECTIVE

To investigate the magnitude and determinants of the placebo response in studies with pediatric abdominal pain-related functional gastrointestinal disorders.

STUDY DESIGN

The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and CINAHL were searched for systematic reviews and randomized placebo-controlled trials concerning children 4-18 years of age with an abdominal pain-related functional gastrointestinal disorder. The primary outcome was the pooled proportion of subjects assigned to placebo with improvement as defined by the authors. The effect of trial characteristics on the magnitude of the placebo response was investigated using univariate meta-regression analysis.

RESULTS

Twenty-one trials were identified. The pooled proportion of subjects with improvement was 41% (95% CI, 34%-49%; 17 studies) and with no pain was 17% (95% CI, 8%-32%; 7 studies). The pooled standardized mean difference on the Faces Pain Scales compared with baseline was -0.73 (95% CI, -1.04 to -0.42; 8 studies). There was significant heterogeneity across studies with respect to both outcomes. Lower dosing frequency (P = .04), positive study (P = .03), longer duration of treatment (P < .001), and higher placebo dropout (P < .001) were associated with higher report of no pain. Response on Faces Pain Scales was greater in studies conducted in the Middle East (P = .002), in studies that did not report the randomization schedule (P = .02), and in studies with a higher percentage of females (P = .04).

CONCLUSIONS

Approximately 41% of children with abdominal pain-related functional gastrointestinal disorders improve on placebo. Several trial characteristics are correlated significantly with the proportion of patients with no pain on placebo and with the magnitude of the placebo response on Faces Pain Scales. These data could be valuable for the design of future studies.

Set and setting, psychedelics and the placebo response: An extra-pharmacological perspective on psychopharmacology

Placebo response theory and set and setting theory are two fields which examine how non-biological factors shape the response to therapy. Both consider factors such as expectancy, preparation and beliefs to be crucial for understanding the extra-pharmacological processes which shape the response to drugs. Yet there are also fundamental differences between the two theories. Set and setting concerns itself with response to psychoactive drugs only; placebo theory relates to all therapeutic interventions. Placebo theory is aimed at medical professionals; set and setting theory is aimed at professionals and drug users alike. Placebo theory is primarily descriptive, describing how placebo acts; set and setting theory is primarily prescriptive, educating therapists and users on how to control and optimize the effects of drugs. This paper examines how placebo theory and set and setting theory can complement and benefit each other, broadening our understanding of how non-biological factors shape response to drugs and other treatment interventions.

Neuro-Bio-Behavioral Mechanisms of Placebo and Nocebo Responses: Implications for Clinical Trials and Clinical Practice

The placebo effect has often been considered a nuisance in basic and particularly clinical research. This view has gradually changed in recent years due to deeper insight into the neuro-bio-behavioral mechanisms steering both the placebo and nocebo responses, the evil twin of placebo. For the neuroscientist, placebo and nocebo responses have evolved as indispensable tools to understand brain mechanisms that link cognitive and emotional factors with symptom perception as well as peripheral physiologic systems and end organ functioning. For the clinical investigator, better understanding of the mechanisms driving placebo and nocebo responses allow the control of these responses and thereby help to more precisely define the efficacy of a specific pharmacological intervention. Finally, in the clinical context, the systematic exploitation of these mechanisms will help to maximize placebo responses and minimize nocebo responses for the patient's benefit. In this review, we summarize and critically examine the neuro-bio-behavioral mechanisms underlying placebo and nocebo responses that are currently known in terms of different diseases and physiologic systems. We subsequently elaborate on the consequences of this knowledge for pharmacological treatments of patients and the implications for pharmacological research, the training of healthcare professionals, and for the health care system and future research strategies on placebo and nocebo responses.

Age and sex as moderators of the placebo response – an evaluation of systematic reviews and meta-analyses across medicine

Predictors of the placebo response (PR) in randomized controlled trials (RCT) have been searched for ever since RCT have become the standard for testing novel therapies and age and gender are routinely documented data in all trials irrespective of the drug tested, its indication, and the primary and secondary end points chosen. To evaluate whether age and gender have been found to be reliable predictors of the PR across medical subspecialties, we extracted 75 systematic reviews, meta-analyses, and meta-regressions performed in major medical areas (neurology, psychiatry, internal medicine) known for high PR rates. The literature database used contains approximately 2,500 papers on various aspects of the genuine PR. These ‘meta-analyses’ were screened for statistical predictors of the PR across multiple RCT, including age and gender, but also other patient-based and design-based predictors of higher PR rates. Retrieved papers were sorted for areas and disease categories. Only 15 of the 75 analyses noted an effect of younger age to be associated with higher PR, and this was predominantly in psychiatric conditions but not in depression, and internal medicine but not in gastroenterology. Female gender was associated with higher PR in only 3 analyses. Among the patient-based predictors, the most frequently noted factor was lower symptom severity at baseline, and among the design- based factors, it was a randomization ratio that selected more patients to drugs than to placebo, more frequent study visits, and more recent trials that were associated with higher PR rates. While younger age may contribute to the PR in some conditions, sex does not. There is currently no evidence that the PR is different in the elderly. PR are, however, markedly influenced by the symptom severity at baseline, and by the likelihood of receiving active treatment in placebo- controlled trials.

Context Effects in Western Herbal Medicine: Fundamental to Effectiveness?

Western herbal medicine (WHM) is a complex healthcare system that uses traditional plant-based medicines in patient care. Typical preparations are individualized polyherbal formulae that, unlike herbal pills, retain the odor and taste of whole herbs. Qualitative studies in WHM show patient-practitioner relationships to be collaborative. Health narratives are co-constructed, leading to assessments, and treatments with personal significance for participants. It is hypothesized that the distinct characteristics of traditional herbal preparations and patient-herbalist interactions, in conjunction with the WHM physical healthcare environment, evoke context (placebo) effects that are fundamental to the overall effectiveness of herbal treatment. These context effects may need to be minimized to demonstrate pharmacological efficacy of herbal formulae in randomized, placebo-controlled trials, optimized to demonstrate effectiveness of WHM in pragmatic trials, and consciously harnessed to enhance outcomes in clinical practice.

Placebo effects and their determinants in gastrointestinal disorders

Placebo effects in clinical trials have sparked an interest in the placebo phenomenon, both in randomized controlled trials (RCTs) and in experimental gastroenterology. RCTs have demonstrated similar short-term and long-term placebo response rates in gastrointestinal compared to other medical diagnoses. Most mediators and moderators of placebo effects in gastrointestinal diseases are also of similar type and size to other medical diagnoses and not specific for gastrointestinal diagnoses. Other characteristics such as an increase in the placebo response over time and the placebo-enhancing effects of unbalanced randomization were not seen, at least in IBS. Experimental placebo and nocebo studies underscore the 'power' of expectancies and conditioning processes in shaping gastrointestinal symptoms not only at the level of self-reports, but also within the brain and along the brain-gut axis. Brain imaging studies have redressed earlier criticism that placebo effects might merely reflect a response bias. These findings raise hope that sophisticated trials and experiments designed to boost positive expectations and minimize negative expectations could pave the way for a practical and ethically sound use of placebo knowledge in daily practice. Rather than focusing on a 'personalized' choice of drugs based on biomarkers or genes, it might be the doctor-patient communication that needs to be tailored.

Placebo response rate in clinical trials of fistulizing Crohn's disease: systematic review and meta-analysis

BACKGROUND & AIMS

It is important to determine the magnitude and identify modifiers of the rate of response to placebo in clinical trials of fistulizing Crohn's disease (CD), to understand disease progression, and to calculate sample size. We conducted a systematic review and meta-analysis of rates of response to placebo in trials of patients with fistulizing CD.

METHODS

We searched MEDLINE, EMBASE, EMBASE CLASSIC, and the Cochrane central register of controlled trials for randomized controlled trials (RCTs) comparing pharmacologic agents with placebo in adults with fistulizing CD. We identified studies that reported complete fistula closure, partial closure, or response. Data were extracted as intention-to-treat analyses and pooled by using a random-effects model. Proportions of patients who received placebo and had complete or partial fistula(e) closure were calculated, with 95% confidence intervals (CIs). The effects of trial characteristics on the magnitude of response to placebo were examined.

RESULTS

Thirteen RCTs were eligible for our analysis; these included 579 patients assigned to placebo groups. The pooled rate of response to placebo, among all RCTs, for complete fistula closure was 15.6% (95% CI, 10.9%-20.9%), with significant heterogeneity (I(2) = 62.5%, P = .001). The pooled rate of response to placebo for partial fistula closure or response in 9 trials, comprising 423 patients, was 18.3% (95% CI, 14.8%-22.1%). Rates of response to placebo were significantly lower in trials with shorter durations of therapy and shorter intervals to assessment of fistula closure. Neither exposure to the pharmacologic agent during the induction phase of the same (or related) RCT nor concomitant medications had any effect.

CONCLUSIONS

In a meta-analysis of rate of response to placebo in patients with fistulizing CD, we found that fistulae closed in almost 1/6 patients given placebo in RCTs of pharmacologic agents. Future research should identify characteristics of patients that predict response to placebo.

Can an educational handout enhance placebo analgesia for experimentally-induced pain?

The placebo effect is an interesting phenomenon whereby a dummy treatment can produce therapeutic benefit, such as, pain relief. While evidence for the placebo effect is growing, relatively few studies have explored ways of enhancing placebo effects. To address this, the current study tested whether placebo-induced analgesia could be enhanced by providing an educational handout about the efficacy of analgesics. Fifty university students were allocated to receive placebo treatment under the guise of a new analgesic formula, either with or without an educational handout, or to a no treatment control group before undergoing electrical and cold pressor pain tests. There was a placebo effect for electrically-induced pain with those receiving placebo treatment reporting significantly less pain compared with those who received no treatment. There was also some evidence of enhancement of this placebo-induced analgesia for electrically-induced pain as a result of the educational handout. No differences were found on cold pressor-induced pain. These findings suggest that providing educational information about a treatment could enhance its efficacy via the placebo effect. Future studies should test different methods of providing educational information in order to determine which elicit the strongest effects.

Restoring psychology's role in peptic ulcer

This paper reviews the history of the transition from the belief that gastrointestinal ulcers are caused primarily by psychological factors to the current state of belief that they are caused primarily by infection and argues that neither is fully accurate. We argue that psychological factors play a significant role as predisposing to vulnerability, modulating of precipitation, and sustaining of gastric ulceration. We review data that challenge the assumption of a simple infectious disease model and adduce recent preclinical data that confirm the predisposing, modulatory, and sustaining roles for psychological factors. We note that others, too, are now challenging the adequacy of the contemporary simple bacterial infection model. We hope to replace the competition between psychology and medicine with cooperation in understanding and treating patients suffering gastric ulceration and ulcer.

Acupuncture for the treatment of hot flashes in patients with breast cancer receiving antiestrogen therapy: a pilot study in Korean women

OBJECTIVES

Antiestrogen therapy can cause vasomotor symptoms similar to those occurring during menopause, including hot flashes. Recent studies suggest that acupuncture is effective in reducing vasomotor symptoms in patients with breast cancer receiving tamoxifen. The purpose of this study was to assess the feasibility and safety of acupuncture for treatment of hot flashes in Korean patients with breast cancer receiving antiestrogen therapy.

DESIGN

This was a prospective single-arm observational study using before and after measurements.

SETTINGS/LOCATION

The study was located at the East-West Medical Center at Daegu Catholic University Medical Center, Daegu, Korea.

SUBJECTS

The subjects were 10 patients with breast cancer who were undergoing antiestrogen therapy with tamoxifen or anastrozole and who were suffering from hot flashes.

INTERVENTIONS

Acupuncture was administered 3 times a week for 4 consecutive weeks, for 20±5 minutes at each session.

OUTCOME MEASURES

The outcome measure was severity of hot flashes assessed by visual analogue scale (VAS) and total hot flash score.

RESULTS

During treatment, severity of hot flashes was reduced by 70%-95% in all patients. Acupuncture significantly alleviated severity of hot flashes assessed by a visual analogue scale (F=30.261; p<0.001) as well as the total hot flash score (F=21.698; p=0.006). Four (4) weeks after the final treatment, symptoms were not aggravated.

CONCLUSIONS

Acupuncture appeared to provide effective relief from hot flashes among Korean women receiving antiestrogen therapy after surgery for breast cancer, and the effects lasted for at least 1 month after termination of treatment. A randomized controlled prospective study with a larger sample size is required to clarify the role of acupuncture in the management of hot flashes in Korean patients with breast cancer.

Placebo response in the prophylaxis of migraine: A meta-analysis

BACKGROUND

Migraine constitutes a good model for the study of placebo response. It is a well-defined disease, affects a large population and a great number of clinical trials have been performed, which have given homogeneous outcomes.

AIM

The aim of this meta-analysis is to evaluate the placebo response rate in migraine prophylaxis in all published clinical trials since 1988 and to estimate the influence of study design in response variability.

METHODS

A computer-based information search was conducted on the Medline database. The outcomes studied were patients who improved (reduction in migraine attacks of 50% or more); attacks per month, and patients with adverse events. Study design and countries in which the study was carried out were also analysed. The meta-analysis was computed using the Mantel-Haenszel test.

RESULTS

In the final analysis, 32 papers were considered. The pooled estimate of the placebo response (patients who improved) was 21%. The placebo response rates were significantly higher in studies with a parallel design than those in cross-over studies (p<0.01). This response was also higher in European studies than in those performed in North America (p<0.001). Adverse events occurred in 30% of the patients who took a placebo, and the percentage of patients with adverse events was significantly higher in the North American studies than in those conducted in Europe (p<0.01).

CONCLUSION

These data reinforce the need to consider the placebo effect when ascertaining the true therapeutic effect of any drug, as well as to design any clinical trial in the prophylaxis of migraine.

Placebo responses and placebo effects in functional bowel disorders

The nature and determinants of the placebo response are widely unknown, as are the underlying psychological and biological mechanisms. Placebo response rates in functional bowel disorders (functional dyspepsia, irritable bowel syndrome) trials are similar to those in nonintestinal pain conditions and are comparable with other organic gastrointestinal diseases (duodenal ulcer, inflammatory bowel diseases). In this narrative review, different methodologies (meta-analyses, reanalyses, and experimental setups) are discussed that have been applied to the study of the placebo response in functional dyspepsia and the irritable bowel syndrome.

A systematic review of the effect of expectancy on treatment responses to acupuncture

Randomised controlled trials (RCTs) of acupuncture often find equivalent responses to real and placebo acupuncture despite both appearing superior to no treatment. This raises questions regarding the mechanisms of acupuncture, especially the contribution of patient expectancies. We systematically reviewed previous research assessing the relationship between expectancy and treatment responses following acupuncture, whether real or placebo. To be included, studies needed to assess and/or manipulate expectancies about acupuncture and relate these to at least one health-relevant outcome. Nine such independent studies were identified through systematic searches of Medline, PsycInfo, PubMed, and Cochrane Clinical Trials Register. The methodology and reporting of these studies were quite heterogeneous, meaning that meta-analysis was not possible. A descriptive review revealed that five studies found statistically significant effects of expectancy on a least one outcome, with three also finding evidence suggestive of an interaction between expectancy and type of acupuncture (real or placebo). While there were some trends in significant effects in terms of study characteristics, their generality is limited by the heterogeneity of study designs. The differences in design across studies highlight some important methodological considerations for future research in this area, particularly regarding whether to assess or manipulate expectancies and how best to assess expectancies.

Reframing placebo in research and practice

The terms 'placebo' and 'placebo effects' cause confusion among patients, practitioners and scientists. This confusion results in both the adoption of practices that have no evidence of specificity yet considerable risk (such as surgery for low back pain) or the elimination of clinical practices proven to facilitate healing because they are not 'better than placebo' (such as acupuncture for low back pain). In this article, I discuss these issues and introduce the concept of optimal healing environment as a framework for disentangling what is useful from placebo research for adopting into clinical practice in a manner that is ethical and evidence-based.

Meta-analysis: the effects of placebo treatment on gastro-oesophageal reflux disease

BACKGROUND

There appears to be a significant placebo response rate in clinical trials for gastro-oesophageal reflux disease. Little is known about the determinants and the circumstances associated with placebo response in the treatment of gastro-oesophageal reflux disease (GERD).

AIMS

To estimate the magnitude of the placebo response rate in randomized controlled trials for GERD and to identify factors that influence this response.

METHODS

A meta-analysis of randomized, double-blind, placebo-controlled trials, published in English language, which included >20 patients with GERD, treated with either a proton pump inhibitor or H(2)-receptor antagonist for at least 2 weeks. Medline, Cochrane and EMBASE databases were searched, considering only studies that reported a global response for 'heartburn'.

RESULTS

A total of 24 studies included 9989 patients with GERD. The pooled odds ratio (OR) for response to active treatment vs. placebo was 3.71 (95% CI: 2.78-4.96). The pooled estimate of the overall placebo response was 18.85% (range 2.94%-47.06%). Patients with erosive oesophagitis had a non-significantly lower placebo response rate than patients without it (11.87% and 18.31%, respectively; P = 0.246). Placebo response was significantly lower in studies of PPI therapy vs. studies of H(2) RAs (14.51% vs. 24.69%, respectively; P = 0.05).

CONCLUSIONS

The placebo response rate in randomized controlled trials for GERD is substantial. A lower placebo response was associated with the testing of PPIs, but not the presence of erosive oesophagitis.

Meta-analysis: factors affecting placebo response rate in the irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a functional disorder of the gastrointestinal tract with a significant placebo response.

AIM

To conduct a systematic review and meta-analysis examining the magnitude of placebo response rate in treatment trials for IBS.

METHODS

MEDLINE, EMBASE and the Cochrane central register of controlled trials were searched to identify randomized controlled trials (RCTs) comparing pharmacological therapies with placebo in adult IBS patients. Studies reported either global assessment of IBS symptom cure or improvement or abdominal pain cure or improvement. Data were extracted as intention-to-treat analyses with drop-outs assumed to be treatment failures and pooled using a random-effects model. Proportion of placebo patients experiencing symptom improvement or resolution was reported with a 95% confidence interval (CI). Effect of trial characteristics on magnitude of placebo response was examined.

RESULTS

In all, 73 RCTs were eligible, including 8364 patients with IBS allocated to placebo. Pooled placebo response rate across all RCTs was 37.5% (95% CI 34.4-40.6%). Rates were higher in European RCTs, RCTs that used physician-reported outcomes and RCTs using shorter duration of therapy.

CONCLUSIONS

Placebo response rates across RCTs of pharmacological therapies in IBS were high. Future research should identify patient characteristics predicting placebo response.

Effects of acupuncture on hot flashes in perimenopausal and postmenopausal women--a multicenter randomized clinical trial

OBJECTIVE

The aim of this study was to evaluate the effectiveness of acupuncture plus usual care for relief of hot flashes and menopause-related symptoms compared with usual care alone in perimenopausal or postmenopausal women.

METHODS

A multicenter, randomized, controlled trial was conducted. Perimenopausal or postmenopausal women with average hot flash scores of 10 or higher during the week before the screening visit were enrolled and randomly divided into two groups. The treatment group received 12 sessions of acupuncture and maintained usual care for 4 weeks, whereas the control group underwent usual care alone. Hot flash scores were calculated by multiplying frequency by severity of hot flashes recorded in a daily diary. The primary outcome was the mean change in the average 24-hour hot flash score at week 4 from baseline. The secondary outcome was the mean change in menopause-related symptoms as estimated by the Menopause Rating Scale questionnaire at week 4. Follow-up assessment at week 8 was conducted in the treatment group only.

RESULTS

The mean change in the average 24-hour hot flash score was -16.57 in the treatment group (n = 116) and -6.93 in the control group (n = 59), a difference of 9.64 (P < 0.0001). The total Menopause Rating Scale score, as well as the subscale scores for the psychological, somatic, and urogenital dimensions of menopause, showed significant improvement in the acupuncture group compared with the control group (P < 0.001). The mean change in the treatment group in the primary outcome was -17.58 at week 8.

CONCLUSIONS

Our results suggest that acupuncture in addition to usual care is associated with marked clinical improvement in hot flashes and menopause-related symptoms in perimenopausal or postmenopausal women.

Cost-Effectiveness Analysis: Discount the Placebo at Your Peril

Introduction: The authors consider alternative mechanisms that might explain placebo responses and their implications for cost-effectiveness modeling. Three alternative placebo mechanisms are examined: a ‘‘regression to the mean’’ effect arising from natural variation and the preferential selection of patients with acutely severe disease into clinical trials, a patient expectancy effect specific to the clinical trial setting (Hawthorne effect), and a patient expectancy effect generalizable to routine clinical practice (true placebo effect). Methods: To estimate cost-effectiveness, the authors needed to generalize from trial data to estimate responses to treatment that they would see in routine clinical practice. They use an example analysis of the cost-effectiveness of adjunct epilepsy treatments to illustrate the potential effects of these different placebo mechanisms on this generalization and subsequent cost-effectiveness estimates and adoption decisions. Results: If an acceptable willingness-to-pay threshold of 30,000 per quality-adjusted life year (QALY) is assumed, then each of the placebo effect scenarios identifies a different treatment alternative as being optimum. Discussion: Estimated cost-effectiveness ratios and associated policy decisions may be sensitive to assumptions regarding the mechanism underlying placebo responses. These assumptions should, if possible, be investigated through analysis of trial or observational data and, in the absence of other evidence, sensitivity analysis.

Would the elderly be better off if they were given more placebos?

Placebos are useful in the medical care of the elderly, although the exact definition of a "placebo" or "placebo effect" is difficult to define precisely. They have an important role as control treatments in research trials, but a non-specific "placebo effect" may also be beneficial part of many physician-patient interactions. Physicians also give them deliberately according to several studies worldwide to satisfy patient demands or because they believe in a "placebo effect" among other reasons. A significant placebo effect has been observed among older patients in clinical trials of antidepressants (12-15%), and in treatments of Parkinson's disease (16%). Placebos activate serotonergic pathways in the brain used by antidepressants. In Parkinson's disease, the administration of a placebo stimulates dopamine release in the dorsal (resulting in motor effects) and ventral striatum (which influences expectation of reward). Much of our understanding of the placebo effect comes from studies of placebo analgesia which is influenced by conditioning, expectation, meaning and context of the treatment for the patient, and patient-physician interaction. It is anatomically medicated by brain opioid pathways. Response to "sham" acupuncture in osteoarthritis may be an example of its use in the elderly. Placebos have often been considered a deception and thus unethical. On the other hand, some physicians and ethicists have suggested conditions for appropriate uses for placebos. A placebo might offer the theoretical advantage of an inexpensive treatment that would not cause adverse drug reactions or interactions with other medications, potentially avoiding complications of polypharmacy.

[The placebo effect in inflammatory bowel disease]

Since time immemorial, placebos have been used in the treatment of patients with very different diseases. Interest in these substances has recently been renewed, since the use of placebo-controlled clinical trials has become the most useful tool to demonstrate the efficacy of a particular drug in patients with specific diseases. In inflammatory bowel disease (IBD), both in Crohn's disease and in ulcerative colitis, highly significant results have been obtained in patients in the placebo arm of clinical trials, surpassing even those achieved with drugs in other studies. Patients with IBD show certain characteristics that make them especially susceptible to the placebo effect: IBD are chronic diseases occurring in flares and pain is one of the main symptoms. In future, the placebo effect should be adequately quantified in the distinct clinical scenarios of IBD in order to design clinical trials that could demonstrate the true efficacy of the treatments investigated.

Reflexology for the treatment of pain in people with multiple sclerosis: a double-blind randomised sham-controlled clinical trial

Multiple sclerosis (MS) results in pain and other symptoms which may be modified by conventional treatment, however, MS is still not curable. Several studies have reported positive effects of reflexology in the treatment of pain, however, no randomised controlled clinical trials for the treatment of pain have been conducted within this population. The objective of this study was to investigate the effectiveness of reflexology on pain in and MS population. We randomly allocated 73 participants to receive either precision or sham reflexology weekly for 10 weeks. Outcome measures were taken pre-and post-treatment with follow-up at 6 and 12 weeks by a researcher blinded to group allocation. The primary outcome measure recorded pain using a Visual Analogue Scale (VAS). A significant (p < 0.0001) and clinically important decrease in pain intensity was observed in both groups compared with baseline. Median VAS scores were reduced by 50% following treatment, and maintained for up to 12 weeks. Significant decreases were also observed for fatigue, depression, disability, spasm and quality of life. In conclusion, precision reflexology was not superior to sham, however, both treatments offer clinically significant improvements for MS symptoms via a possible placebo effect or stimulation of reflex points in the feet using non-specific massage.

The "placebo" response in osteoarthritis and its implications for clinical practice

Many observations support a major biological effect from the way in which people interpret the meaning of each component of their medical experience and the context in which this occurs. A recent systematic review of randomised controlled trials in osteoarthritis has demonstrated that the effect size of "placebo" is substantial and is usually greater than that obtained from the specific effect of an individual treatment. In the context of a randomised controlled trial, such a large placebo or "meaning" response is considered a nuisance, but in the context of clinical practice the optimisation of such meaning and contextual responses, through enhanced "care", could greatly benefit people who suffer from osteoarthritis.

Meta-analysis: incidence of endoscopic gastric and duodenal ulcers in placebo arms of randomized placebo-controlled NSAID trials

BACKGROUND

The safety of NSAIDs is often evaluated by comparison with placebo in clinical trials.

AIM

To investigate the incidence of gastric and duodenal ulcers (GDU) in placebo arms in NSAID trials over the last three decades.

METHODS

Randomized placebo-controlled trials of oral NSAIDs from 1975 to 2006 were systematically reviewed. The pooled incidence of GDU in placebo arms was calculated and compared. Meta-regression was used to identify risk factors related to the incidence of the placebo ulcer at the study level.

RESULTS

Thirty-six studies met inclusion criteria (duration of 6.5 days to 24 weeks). In total, 3.29% GDUs were reported in 36 placebo arms. The incidence of GDU in placebo arms was 0, 4.20% and 3.03% in the studies from 1975-1989, 1990-1999 and 2000-2006 respectively (P > 0.05). Eligible subjects with previous GI events and eligible subjects on co-therapy with low-lose aspirin/corticosteroids were associated with the increase in placebo ulcer incidence after adjusting for other factors.

CONCLUSIONS

The incidence of GDU in placebo arms has not changed significantly over the last three decades, although has decreased in the past 10 years. Studies show that previous GI events and co-therapy with low-dose aspirin/corticosteroids were associated with increasing GDU in placebo arms.

Placebo effects: clinical aspects and neurobiology

Placebo effects are beneficial health outcomes not related to the relatively direct biological effects of an intervention and can be elicited by an agent that, by itself, is inert. Understanding these placebo effects will help to improve clinical trial design, especially for interventions such as surgery, CNS-active drugs and behavioural interventions which are often non-blinded. A literature review was performed to retrieve articles discussing placebo implications of clinical trials, the neurobiology of placebo effects and the implications of placebo effect for several disorders of neurological relevance. Recent research in placebo analgesia and other conditions has demonstrated that several neurotransmitter systems, such as opiate and dopamine, are involved with the placebo effect. Brain regions including anterior cingulate cortex, dorsolateral prefrontal cortex and basal ganglia have been activated following administration of placebo. A patient's expectancy of improvement may influence outcomes as much as some active interventions and this effect may be greater for novel interventions and for procedures. Maximizing this expectancy effect is important for clinicians to optimize the health of their patient. There have been many relatively acute placebo studies that are now being extended into clinically relevant models of placebo effect.