Powerful placebo: the dark side of the randomised controlled trial

Influence of patient-clinician relationship style on acupuncture outcomes in functional dyspepsia: A multi-site randomized controlled trial in Korea

INTRODUCTION

Research suggests that a warm and empathic "patient-centered" patient-clinician relationship produces better clinical outcomes when compared with a more neutral "disease-centered" relationship. Acupuncturists performed both styles of therapy for patients with functional dyspepsia in Korea.

METHODS

The present randomized controlled trial assigned patients (n = 73) to identical acupuncture treatment with either patient-centered augmented care or disease-centered limited care. The Korean version of the Nepean Dyspepsia Index (NDI-K) was the primary outcome measure. Secondary outcome measures included Consultation And Relational Empathy (CARE) scale.

RESULTS

Both groups showed improvement in NDI-K. Patient-centered augmented acupuncture produced less effective symptom improvement compared to disease-centered limited acupuncture (NDI-K sum score and frequency; P = 0.008 and P = 0.037 respectively). CARE scores were higher for the augmented versus limited group (P = 0.001), supporting the fidelity of the experimentally controlled patient/clinician relationship. There were no significant differences between the groups in any of other secondary outcomes.

CONCLUSION

Patients demonstrated greater improvement following acupuncture conducted with a more neutral, "disease-centered" style of relationship. This result is counter to similar research conducted in Western countries and suggests that cultural factors can significantly shape optimum styles of acupuncture therapy.

PRACTICE IMPLICATIONS

Clinicians should consider cultural differences when applying acupuncture therapy.

Limits of ethical non-human subjects research in an applied setting

Ethical research follows numerous rules and regulations to ensure that all human subjects are protected during the collection and dissemination of research outcomes. Nevertheless, there is often a critical distinction drawn between human subjects research and non-human subjects research (NHSR). The latter can also be described as non-research activities, which typically reduces any oversight even if human subjects are involved. Despite the need to conduct ethical NHSR or non-research activities in an applied setting, there are several ways this determination can be used to circumvent regulatory oversight. In particular, the problem arises because one or more of several key functions become conflated in an applied setting, whereas they would be compartmentalized and independent in controlled or experimental settings. These functions include: 1) ethical oversight; 2) funding; 3) execution; and 4) peer review. The current discussion outlines how NHSR in an applied setting can allow these functions to overlap, and how personnel might stretch the boundaries of ethical conduct even while following existing regulations. As such, the goal is to guide future practices when conducting or reviewing NHSR in an applied setting so that unethical practices do not bias the results.

Open-label placebos-a systematic review and meta-analysis of experimental studies with non-clinical samples

The use of open-label placebos (OLPs) has shown to be effective in clinical trials. We conducted a systematic review and meta-analysis to examine whether OLPs are effective in experimental studies with non-clinical populations. We searched five databases on April 15, 2021. We conducted separate analyses for self-reported and objective outcomes and examined whether the level of suggestiveness of the instructions influenced the efficacy of OLPs. Of the 3573 identified records, 20 studies comprising 1201 participants were included, of which 17 studies were eligible for meta-analysis. The studies investigated the effect of OLPs on well-being, pain, stress, arousal, wound healing, sadness, itchiness, test anxiety, and physiological recovery. We found a significant effect of OLPs for self-reported outcomes (k = 13; standardized mean difference (SMD) = 0.43; 95% CI = 0.28, 0.58; I² = 7.2%), but not for objective outcomes (k = 8; SMD =  - 0.02; 95% CI =  - 0.25, 0.21; I² = 43.6%). The level of suggestiveness of the instructions influenced the efficacy of OLPs for objective outcomes (p = 0.02), but not for self-reported outcomes. The risk of bias was moderate for most studies, and the overall quality of the evidence was rated low to very low. In conclusion, OLPs appear to be effective when examined in experimental studies. However, further research is needed to better understand the mechanisms underlying OLPs.

Placebo effects in functional dyspepsia: Causes and implications for clinical trials

Placebo responses to an apparently inactive intervention are of interest from a scientific perspective as they suggest possible mechanism(s) at work beyond the intervention itself. They are also of interest from a clinical trials perspective since high rates of placebo response limit the potential to demonstrate worthwhile efficacy of a new intervention. This mini-review was motivated by the work of Bosman and colleagues(Neurogastroenterol Motil, 2022, and e14474) that is published in this issue of the journal in which they report on a systematic review and meta-analysis of placebo response in functional dyspepsia clinical trials. The review sets the scene for their work by putting it in the context of other disorders of brain-gut interaction and extra-gastrointestinal disorders. The review canvasses potential mechanisms of placebo response.

Neural underpinnings of open-label placebo effects in emotional distress

While placebo effects are well-known, research in the last decade revealed intriguing effects that placebos may have beneficial effects even when given without deception. At first glance, this seems paradoxical, but several studies have reported improvements in pain, depression, or anxiety. However, it still remains unclear whether these results represent objective biological effects or simply a bias in response and what neural underpinnings are associated with the open-label placebo effects. In two studies, we address this gap by demonstrating that open-label placebos reduce self-reported emotional distress when viewing highly arousing negative pictures. This reduced emotional distress was associated with an activation of brain areas known to modulate affective states such as the periaqueductal gray, the bilateral anterior hippocampi, and the anterior cingulate cortex. We did not find any prefrontal brain activation. Furthermore, brain activation was not associated with expectation of effects. In contrast, we found that brain responses were linked to general belief in placebos. The results demonstrate that the neural mechanisms of open-label placebo effects are partly identical to the neurobiological underpinnings of conventional placebos, but our study also highlights important differences with respect to a missing engagement of prefrontal brain regions, suggesting that expectation of effects may play a less prominent role in open-label placebos.

Current status of neuroimaging research on the effects of acupuncture: a bibliometric and visual analyses

OBJECTIVE

To conduct an inductive analysis of neuroimaging studies following the global popularity surrounding the effects of acupuncture.

METHODS

The relevant works of literature on acupuncture effects-related neuroimaging studies were retrieved from the web of science core collection database from the date of its establishment to 2022. Bibexcel software was used to extract information, such as article numbers, countries, journals, agencies, funding sources and keywords. The VOSviewer software's co-occurrence and clustering module was used for the co-occurrence and cluster analysis of collaborative networks and high frequency keywords, such as authors, institutions and countries.

RESULTS

Neuroimaging research on the effects of acupuncture began in the 1960 s and has since received the extensive attention of scholars. China, The United States and South Korea conduct more neuroimaging research on the effects of acupuncture than other countries. Academic journals such as Evidence-Based Complementary and Alternative Medicine, Journal of Alternative and Complementary Medicine, Neural Regeneration Research and Acupuncture in Medicine have published the highest number of acupuncture-related neuroimaging articles. Moreover, cluster analysis differentiates high-frequency keywords into six clusters. Furthermore, the use of the keyword 'density atlas' reveals that neuroimaging research on the effects of acupuncture surrounding pain and neurofunctional rehabilitation is currently the research focus.

CONCLUSIONS

This bibliometric study identifies six important research hot spots: Static brain functional connectivity analysis of acupuncture analgesic effects, key theories on the scientific problems of acupuncture, acupuncture analgesic effect of the placebo effect, the neuroimaging of acupoint ST-36, the value of acupuncture in regulating the autonomic nerves and acupuncture therapy as complementary medicine.

Efficacy of Xinbao pill on chronic heart failure: Study protocol of a multicenter, randomized, double-blind, placebo-controlled trial

Introduction: Chronic heart failure (CHF) is a common cardiovascular disease. In China, Xinbao pill (XBP) is widely used as an adjuvant therapy for CHF. However, there is still a lack of high-quality clinical evidence. We designed this multicenter, randomized, double-blind, placebo-controlled trial to critically evaluate the efficacy and safety of XBP as an adjuvant treatment for patients with CHF.

Methods and analysis: We will recruit 284 patients with a clinical diagnosis of “heart-kidney yang deficiency syndrome” CHF receiving treatment in six hospitals in China. Patients will be randomly assigned, in a 1:1 ratio, to the treatment or control group using a central randomization system. All patients will receive conventional drug therapy for heart failure combined XBP (Guangdong Xinbao Pharmaceutical Co., Ltd., Guangdong, China) or a placebo. Study physicians, subjects, outcome assessors, and statisticians will be blinded to the group assignment. The primary outcome will be the change in the proportion of patients who show a decrease in serum NT-proBNP of more than 30% after treatment. Secondary outcomes are NYHA class, 6-minute walk distance test, Minnesota Quality of Life Scale score, endpoint events, serum NT-proBNP, echocardiographic parameters, and traditional Chinese medicine (TCM) symptom score. Adverse events will be monitored throughout the trial. Data will be analyzed according to a predetermined statistical analysis plan.

Discussion: The results of this study will provide solid evidence of the safety and efficacy of XBP as an alternative and complementary treatment measure for patients with CHF.

Clinical Trial Registration: Chinese Clinical Trial Registration Center (ChiCTR2000038492).

Oxytocin and the social facilitation of placebo effects

Significant clinical improvement is often observed in patients who receive placebo treatment in randomized double-blind placebo-controlled trials. While a proportion of this "improvement" reflects experimental design limitations (e.g., reliance on subjective outcomes, unbalanced groups, reporting biases), some of it reflects genuine improvement corroborated by physiological change. Converging evidence across diverse medical conditions suggests that clinically-relevant benefits from placebo treatment are associated with the activation of brain reward circuits. In parallel, evidence has accumulated showing that such benefits are facilitated by clinicians that demonstrate warmth and proficiency during interactions with patients. Here, we integrate research on these neural and social aspects of placebo effects with evidence linking oxytocin and social reward to advance a neurobiological account for the social facilitation of placebo effects. This account frames oxytocin as a key mediator of treatment success across a wide-spectrum of interventions that increase social connectedness, thereby providing a biological basis for assessing this fundamental non-specific element of medical care.

Blinding and expectancy confounds in psychedelic randomized controlled trials

Introduction: There is increasing interest in the potential for psychedelic drugs such as psilocybin, LSD and ketamine to treat several mental health disorders, with a growing number of randomized controlled trials (RCTs) being conducted to investigate the therapeutic effectiveness of psychedelics.Areas covered: We review previous literature on expectancy effects and blinding in the context of psychedelic RCTs - literature which strongly suggest that psychedelic RCTs might be confounded by de-blinding and expectancy. We conduct systematic reviews of psychedelic RCTs using Medline, PsychInfo and EMBASE (Jan 1990 - Nov 2020) and show that currently reported psychedelic RCTs have generally not reported pre-trial expectancy, nor the success of blinding procedures.Expert opinion: While psychedelic RCTs have generally shown promising results, with large effect sizes reported, we argue that treatment effect sizes in psychedelic RCTs are likely over-estimated due to de-blinding of participants and high levels of response expectancy. We suggest that psychedelic RCTs should routinely measure de-blinding and expectancy. Careful attention should be paid to clinical trial design and the instructions given to participants to allow these confounds to be reduced, estimated and removed from effect size estimates. We urge caution in interpreting effect size estimates from extant psychedelic RCTs.

The Need for Multidisciplinary Research within the History and Theory of Homeopathy

The controversial issue of homeopathy's scientificity will, in all probability, not be settled by means of clinical trials alone, as long as uncertainty or ignorance about methodological, philosophical, and socio-economical essentials prevail on both sides of the argument. Rather than uncritically adopt the standards of the currently predominant paradigm, homeopathy should not forget its roots, peculiarities, and self-conception. Contrary to conventional medicine, it is based on a teleological image of humanity, a holistic and sustainable approach towards curing sickness, and an up-to-date concept of medical theory in terms of healing arts. However, under today's frameworked conditions of industrialisation, commercialisation and commodification, the strengths of homeopathy tend to be disregarded or even attacked, and a special kind of reductionist and materialist rationality, compatible with expanding markets and profits, is preferably facilitated. To reveal and demonstrate these developments and relationships on a scientific level, there is a need for multidisciplinary research on the part of the humanities, such as history and theory of medicine, history and theory of science, history of economics, sociology of scientific knowledge, and philosophy.

Placebo Response in Patients with Oral Therapy for Overactive Bladder: A Systematic Review and Meta-analysis

CONTEXT

The role of a placebo response in the management of overactive bladder (OAB) remains unclear.

OBJECTIVE

The aim of this review is to methodically study the placebo response extracted from the control arms of randomized clinical trials assessing therapy in patients with OAB.

EVIDENCE ACQUISITION

Medline (PubMed), The Cochrane Library, EMBASE, and Scopus were searched to identify randomized controlled trials (RCTs) published until September 2019. Randomized placebo-controlled trials investigating oral drug therapy for OAB were included. The articles were critically appraised by two reviewers. The primary outcomes were the placebo response in the main patient-reported urinary outcomes together with assessing the impact of patient demographic factors on the placebo response.

EVIDENCE SYNTHESIS

The initial search resulted in 1982 records after reviewing the titles and abstracts, and reference lists of other systematic reviews; 57 studies with an overall estimated 12 901 patients were included in the meta-analysis. The included studies were of overall high/acceptable quality. The standardized mean difference was -0.45 (95% confidence interval [CI] -0.51 to -0.40; p<0.001) for daily micturition episodes, -0.33 (95% CI -0.42 to -0.24; p<0.001) for daily nocturia episodes, -0.46 (95% CI -0.55 to -0.37; p<0.001) for urgency urinary incontinence episodes, -0.50 (95% CI -0.61 to -0.39; p<0.001) for daily urgency episodes, -0.51 (95% CI -0.60 to -0.43; p<0.001) for daily incontinence episodes, and 0.25 (95% CI 0.211-0.290; p<0.001) for volume voided per micturition. The meta-regression of age-related impact of the placebo response on nocturia showed a slope of -0.02 (p<0.001).

CONCLUSIONS

Placebo has a statistically significant effect on improving symptoms and signs associated with OAB; this effect is age dependent. However, there is no consensus on what change of OAB symptoms and signs is clinically meaningful for the affected patient. Taken together, the placebo response seems to be non-negligible in OAB, supporting the need for placebo control in RCTs.

PATIENT SUMMARY

Placebo is an inert treatment method often used in clinical research for comparison with active treatment. However, studies show that placebo has an effect of its own. A placebo response means the total improvement resulting from receiving a placebo. In our study, placebo had a significant role in improving the symptoms of overactive bladder.

Use of Nonmedicated Control Substances in Randomized Clinical Trials of Patients With Chronic Rhinosinusitis: A Systematic Review and Single-Arm Meta-analysis

Importance

The effect of nonmedicated control substances in chronic rhinosinusitis remains unclear.

Objective

To assess the association of nonmedicated control substances in randomized clinical trials with disease outcomes in patients diagnosed with chronic rhinosinusitis.

Data Sources and Study Selection

In this single-arm systematic review and meta-analysis, the Cochrane Library of Systematic Reviews, Ovid MEDLINE, Embase, PubMed, and ClinicalTrials.gov databases were searched for randomized clinical trials with a preintervention and postintervention design for chronic rhinosinusitis that were published between 1946 and January 23, 2019.

Data Extraction and Synthesis

Paired reviewers independently extracted data. The analyses used random-effects models and the Cochrane risk of bias assessment to rate the quality of the evidence.

Main Outcomes and Measures

The primary outcomes were the association of nonmedicated control substances with 22-item Sinonasal Outcome Test (SNOT-22) scores or nasal symptom scores when SNOT-22 was not available.

Results

A total of 2305 abstracts were identified and screened, 725 articles were reviewed in full text, and 38 articles met the study criteria and were included in the meta-analysis. Among the 38 included studies, a total of 2258 adults (mean age range, 27-53 years; 20.0%-72.5% women) were randomized to receive nonmedicated control substances or sham interventions. Topical nonmedicated control substances were associated with significant reduction in SNOT-22 scores (mean difference [MD], -8.81; 95% CI, -12.60 to -5.03). A subgroup analysis of topical therapies, limited to saline irrigation and nasal spray diluents, found that topical diluents were associated with a greater reduction in SNOT-22 scores (MD, -11.45; 95% CI, -13.50 to -9.41) compared with saline irrigation (MD, -13.60; 95% CI, -19.95 to -7.25). Nonmedicated control substances were associated with a significant reduction in nasal obstruction scores (standardized MD [SMD], -0.42; 95% CI, -0.81 to -0.03). No significant change was found in rhinorrhea scores (SMD, -0.34; 95% CI, -1.37 to 0.69), postnasal drip scores (SMD, -0.96; 95% CI, -2.18 to 0.25), facial pain scores (SMD, -0.57; 95% CI, -1.68 to 0.55), or loss of smell scores (SMD, -0.18; 95% CI, -0.68 to 0.32).

Conclusions and Relevance

This systematic review and meta-analysis of the use of nonmedicated control substances in randomized clinical trials of chronic rhinosinusitis outcomes suggests that the use of nonmedicated control substances is associated with limited improvements in SNOT-22 and nasal obstruction scores. These findings highlight potential areas of future research directions and the importance of randomized clinical trials to accurately estimate treatment effect.

Placebo Effects in Acupuncture

This article is a summary of a talk presented in February 2019 at a conference on acupuncture sponsored by the National Institutes of Cancer (NCI) and the National Center for Complementary and Integrative Health (NCCIH) at the National of Institutes of Health (NIH). The article touches on the history of placebos in biomedicine and its absence in traditional East Asian Medicine. It then examines some of the predicaments of evaluating acupuncture's efficacy in relationship to placebo controls. Although acupuncture in randomized controlled trials (RCTs) generally demonstrate equivalence or even superiority to medical interventions or other nonpharmacologic therapies, acupuncture's ability to show superiority to placebo controls has been inconclusive, contradictory and, at best, modest. This article highlights the efforts of the German health insurance funds to evaluate acupuncture. Using a large meta-analysis, the article summaries acupuncture's effectiveness and efficacy. Subsequently, RCTs and meta-analyses testing the hypothesis that sham acupuncture, and other device placebos, have augmented placebo responses are described. It seems that acupuncture, and devices in general, have enhanced placebo responses. These findings may be relevant to designing and evaluating placebo-control acupuncture RCTs. Research into placebo acupuncture may also be helpful for other conditions where detection of intervention-placebo differences can be problematic. Further research is warranted.

Placebos in chronic pain: evidence, theory, ethics, and use in clinical practice

Despite their ubiquitous presence, placebos and placebo effects retain an ambiguous and unsettling presence in biomedicine. Specifically focused on chronic pain, this review examines the effect of placebo treatment under three distinct frameworks: double blind, deception, and open label honestly prescribed. These specific conditions do not necessarily differentially modify placebo outcomes. Psychological, clinical, and neurological theories of placebo effects are scrutinized. In chronic pain, conscious expectation does not reliably predict placebo effects. A supportive patient-physician relationship may enhance placebo effects. This review highlights "predictive coding" and "bayesian brain" as emerging models derived from computational neurobiology that offer a unified framework to explain the heterogeneous evidence on placebos. These models invert the dogma of the brain as a stimulus driven organ to one in which perception relies heavily on learnt, top down, cortical predictions to infer the source of incoming sensory data. In predictive coding/bayesian brain, both chronic pain (significantly modulated by central sensitization) and its alleviation with placebo treatment are explicated as centrally encoded, mostly non-conscious, bayesian biases. The review then evaluates seven ways in which placebos are used in clinical practice and research and their bioethical implications. In this way, it shows that placebo effects are evidence based, clinically relevant, and potentially ethical tools for relieving chronic pain.

[Placebo effects in pain therapy]

In the past few decades, research on pain and placebo analgesia has gained importance both scientifically and clinically. In this article, the current findings and focus of research as well as the significance of placebo research for assessing the effectiveness of pain medication are illustrated. The underlying mechanisms of placebo analgesia not only have implications for theoretical models but also offer clinically relevant guidelines for everyday interventions in pain treatment. However, many placebo phenomena are not fully understood and have to be investigated further in order to exploit the full potential of placebo effects. Interindividual differences and their inclusion in treatment will play a major role in this aspect.

Better than nothing: A historical account of placebos and placebo effects from modern to contemporary medicine

Throughout the history of medicine, multiple conceptions of "placebo" and "placebo effect" have often co-existed across different domains, and today the meaning of these concepts is still disputed. Against this background, this chapter provides a succinct account of the key events in the history of the concepts of "placebo," "placebo control," and "placebo effect." The first section reconstructs the etymology of the term "placebo" and its first introduction in medicine. The next sections provide an account of how placebos have been employed in both medical practice and scientific research in modern medicine. Later sections trace the emergence of the concepts of "placebo control" and "placebo effect" in the first half of the 20th century, from the first empirical studies investigating the effects of placebos up to the publication of Beecher's landmark article "The Powerful Placebo." Finally, the last two sections review the varieties of randomized, placebo-controlled trials (RCTs) in the second half of the 20th century, and the subsequent wave of empirical studies that, starting from the 1970s, have investigated the psychological, pharmacological and neurobiological mechanisms of placebo effects.

Medical practice and placebo response: an inseparable bond?

The history of medicine and the history of placebo are closely intertwined. To understand placebo and its effects this article gives a brief overview about its history, the possible mechanisms of action and its counterpart, nocebo.

The Catholic Church used placebo around the sixteenth century for the separation from real and incorrect exorcisms, but it needed Henry Beecher during World War II to quantify the placebo effect as control arm in well-designed studies.

Until today the different mechanisms of action of placebo remain poorly researched. Understanding them would allow its effect to be modulated to better serve in research and clinical settings. Expectation, psychosocial context and conditioning play a significant role in the effect size and amplitude.

The counterpart, nocebo, is even less investigated, even it is commonly observed as adverse effects during medical treatments.

Conclusion: Placebo and nocebo are both underestimated and underresearched in their value. Through further investigation doctors could strengthen the placebo response and prevent adverse effects to help their patients at low cost. These techniques would benefit the patient-doctor relationship, which is the alter of a trust-based successful therapy.

Impact of Crude Palm Oil Fortified Cookies Supplementation on Anthropometry, Vitamin A and Hematological Status of School Children in India

Abstract. Objectives: Food-based strategies remain the most sustainable solutions for combating micronutrient deficiencies. Crude palm oil being the richest natural source of β-carotene, the study aimed to assess the impact of crude palm oil fortified cookies supplementation on anthropometry, vitamin A and hematological status of school children.

Methods: 444 children (boys-226, girls-218), aged 5-13 years from two Municipal Corporation of Delhi primary schools were enrolled. By draw of lot, children from one of the schools formed the experimental (n = 224; boys-119, girls-105) while other formed the placebo group (n = 220; boys-107; girls-113). Children from the experimental group received six crude palm oil fortified cookies providing 2152 μg of β-carotene while the placebo group received similar but non-fortified cookies each day for 50 school days. Anthropometry, vitamin A, and hematological status were assessed at baseline and post supplementation.

Results: Post supplementation, the number of stunted subjects reduced significantly (p < 0.05) in the experimental group. There was a significant increase in plasma retinol (170.9%; mean change: 1.55 ± 1.30 μmol/L - experimental group vs. 0.45 ± 0.99 μmol/L - placebo group) and β-carotene (p < 0.01; median change from 0.55 to 0.76 μmol/L - experimental group vs. 0.59 to 0.55 μmol/L -placebo group) concentrations of the experimental group. The increase in hematological parameters (mean change in Hemoglobin: 1.64 g/dL in experimental group vs. 2.10 g/dL in placebo group) of both the groups were however, comparable.

Conclusion: To address micronutrient deficiencies particularly in developing nations, the use of crude palm oil should be encouraged through supplementary feeding programs by way of ready-to-eat snacks.

Pain, placebo, and test of treatment efficacy: a narrative review

Over the past decade, the mechanisms underlying placebo effects have begun to be identified. At the same time, the placebo response appears to have increased in pharmacological trials and marked placebo effects are found in neurostimulation and surgical trials, thereby posing the question whether non-pharmacological interventions should be placebo-controlled to a greater extent. In this narrative review we discuss how the knowledge of placebo mechanisms may help to improve placebo control in pharmacological and non-pharmacological trials. We review the psychological, neurobiological, and genetic mechanisms underlying placebo analgesia and outline the current problems and potential solutions to the challenges with placebo control in trials on pharmacological, neurostimulation, and surgical interventions. We particularly focus on how patients' perception of the therapeutic intervention, and their expectations towards treatment efficacy may help develop more precise placebo controls and blinding procedures and account for the contribution of placebo factors to the efficacy of active treatments. Finally, we discuss how systematic investigations into placebo mechanisms across various pain conditions and types of treatment are needed in order to 'personalise' the placebo control to the specific pathophysiology and interventions, which may ultimately lead to identification of more effective treatment for pain patients. In conclusion this review shows that it is important to understand how patients' perception and expectations influence the efficacy of active and placebo treatments in order to improve the test of new treatments. Importantly, this applies not only to assessment of drug efficacy but also to non-pharmacological trials on surgeries and stimulation procedures.

The placebo and its effects: A psychoneuroendocrinological perspective

Placebos are usually employed deceptively in clinical trials in order to control for non-specific effects. However, since placebos themselves have been found to cause clinically relevant changes and in some cases are indistinguishable from the verum they are tested against, this theoretically inert, but practically effective intervention has become a scientific discipline in its own right. In this review, it is argued that placebos are generic and genuine biopsychosocial interventions and as such are highly interesting candidates for a psychoneuroendocrinological perspective. Yet, despite a considerable conceptual proximity between explanatory models of placebos and their effects with psychoneuroendocrine models and findings, placebos have thus far not been subject to systematic psychoneuroendocrine examination. Consequently, it would be highly interesting and informative to make placebos the target of psychoneuroendocrine scrutiny.

Systems pharmacogenomics - gene, disease, drug and placebo interactions: a case study in COMT

Disease, drugs and the placebos used as comparators are inextricably linked in the methodology of the double-blind, randomized controlled trial. Nonetheless, pharmacogenomics, the study of how individuals respond to drugs based on genetic substrate, focuses primarily on the link between genes and drugs, while the link between genes and disease is often overlooked and the link between genes and placebos is largely ignored. Herein, we use the example of the enzyme catechol-O-methyltransferase to examine the hypothesis that genes can function as pharmacogenomic hubs across system-wide regulatory processes that, if perturbed in andomized controlled trials, can have primary and combinatorial effects on drug and placebo responses.

Influencing Side-Effects to Medicinal Treatments: A Systematic Review of Brief Psychological Interventions

Background: Nocebo effects contribute to a large proportion of the non-specific side-effects attributed to medications and are mainly generated through negative expectations. Previous reviews show that interventions designed to change participants' expectations have a small effect on pain experience. They are also effective in reducing side-effects caused by exposure to sham medications. To date, there has been no review of the influence of such interventions on symptoms attributed to real medicinal treatments. Objective: To review studies using a randomized controlled design testing the effect of brief psychological interventions compared to usual practice on the side-effect experience to medicinal treatments in healthy volunteers and patients. Methods: We searched Web of Science, Scopus, Medline, PsycINFO, PsycARTICLES, and Cochrane CENTRAL using search terms for randomized controlled trials along with "nocebo," "placebo effect," "medication," "side-effects," and associated terms. Studies were eligible if they studied a human population, used an active medicine, delivered a brief psychological intervention intended to influence side-effect reporting compared to usual care or no intervention, and used a randomized controlled design. Because of the heterogeneity of the literature we used a narrative synthesis and assessed evidence quality using the GRADE approach. Results: Our database search and supplementary search of the reference sections of included studies retrieved 50,140 citations. After screening, full text review and manual reference searches, 27 studies were included. The quality of the studies and evidence was judged to be low. The strongest and most consistent effect came from omitting side-effect information, although surprisingly de-emphasizing side-effects did not affect side-effect reporting. Other techniques, including priming, distraction, and altering the perception of branding, produced mixed results. Conclusion: Brief psychological interventions can influence side-effect reporting to active medications. Research is currently investigating new ways to de-emphasize side-effects whilst still upholding informed consent, but larger confirmatory trials with suitable control groups are needed. The literature in this area would be improved by more detailed reporting of studies.

Conference proceedings of the 4th Masterclass Psychiatry: Transcultural Psychiatry - Diagnostics and Treatment, Luleå, Sweden, 22-23 February 2018 (Region Norrbotten in collaboration with the Maudsley Hospital and Tavistock Clinic London)

BACKGROUND

According to estimates from the European Commission, Europe has experienced the greatest mass movement of people since the Second World War. More than one million refugees and migrants have arrived in the European Union in the past few years. Mental health and primary care professionals are more likely than ever to meet patients from different cultures and backgrounds.

AIMS

To equip mental health and primary care professionals with transcultural skills to deal with patients from unfamiliar backgrounds.

METHOD

Lectures and case discussions to explore the latest advances in the diagnosis and treatment of serious mental health problems in a transcultural context.

RESULTS

Lectures covered transcultural aspects of mental health problems, treatment in different cultural and ethnic contexts, and assessment of risk factors for self-harm and harm in migrant populations.

CONCLUSIONS

Clinicians require a sound grounding in transcultural skills to confidently and empathically deal with patients from unfamiliar backgrounds.

Placebo and cultural responses

BACKGROUND

Features of placebo response in medicine have been forgotten and ignored over the last decade.

AIM

To explore why patients do get better with placebo despite its perceived inertness.

METHODS

This lecture reviews the relation between illness perception, psychopharmacology and culture.

RESULTS

Placebo response must be considered in the context of how patients perceive their experience of disease (illness) and through their own cultures, which determine cognitive schema and explanatory model of illness. Most of the placebo response relies on the classical conditioning and expectancy of patients. Moreover, the colour, size, formulation, cost of medications can affect the psychological response to any pharmacological treatment.

CONCLUSIONS

Modern psychopharmacology should consider placebo and cultural variations as relevant factors of treatment response.

Clinical Use of Placebo Effects in Patients With Pain Disorders

The analgesic placebo effect is well documented by numerous studies. Many important influencing factors, however, are yet to be discovered. In the arena of placebo effects and clinical implications, expectancies play a central role. Expectancies are shaped by processes of classical and social learning as well as verbal instructions and are strongly related to emotional factors. Expectancies trigger a cascade of endogenous opioids and non-opioids, which alter the experience of pain. For clinical application it is important to know, that placebo research yields ethical possibilities to use placebo effects without deception and without using placebos. Since placebo effects contribute to responses to active analgesics, it is feasible to enhance patients' benefits from pain treatments by increasing the additional placebo effect. There are several possibilities to use the placebo effects via shaping and adapting information about analgesic medication and via associating medication intake with a positive context. A positive patient-clinician communication atmosphere is very important to generate clinically meaningful placebo effects in pain medicine.

Can knowledge of Placebo and Nocebo Mechanisms Help Improve Randomized Clinical Trials?

Over the last decade, there has been a substantial increase in negative results from randomized controlled trials (RCTs), which may be due to an increasing placebo response among other factors. Currently, identification and exclusion of placebo responders from trials are attempted to overcome this problem, but so far the success of these approaches has been limited. At the same time, the placebo-mechanism literature has highlighted how contextual factors, such as patients' expectations, interfere with the effect of drug administration, leading to a certain degree of uncertainty in RCTs. In this chapter, we review the current challenges of RCTs including the uncertainties of the active arm, the placebo arm, the additivity assumption, and the double-blind procedure. We use the placebo-mechanism literature to debate the strengths and weaknesses of attempts to identify and exclude placebo responders from trials. Finally, we illustrate how insights from the placebo-mechanism literature may point to new ways of improving RCTs.

Rethinking placebo in psychiatry: the range of placebo effects

This article, the first of two on placebo effects, provides a broad overview of placebo in the field of medicine. A brief conceptual history is followed by some basic facts about placebos. Problems of definition are identified. Additive and non-additive models of treatment effects, and problems of measurement of placebo effects are described. The role of placebo in the pharmacotherapy of depression and complementary and alternative medicine is discussed. The ‘efficacy paradox’ (that placebo treatments can have larger effects than ‘evidence-based treatments’) is introduced. Finally, ethical issues are discussed.

Erectile function recovery in men treated with phosphodiesterase type 5 inhibitor administration after bilateral nerve-sparing radical prostatectomy: a systematic review of placebo-controlled randomized trials with trial sequential analysis

The impact of phosphodiesterase type 5 inhibitor (PDE5I) treatment modality (on-demand vs. daily), PDE5I half-life and time from surgery to PDE5I prescription on the achievement of drug-assisted erectile function (EF) recovery is uncertain. We systematically reviewed published randomized clinical trials (RCTs). We performed meta-analyses of data on 2317 men treated with PDE5Is after nerve-sparing radical prostatectomy (NSRP). A PubMed and SCOPUS search was performed for trials published from 1 January 1969 to 30 June 2016. PDE5Is are effective in achieving drug-assisted recovery of erectile function (EF). From a statistical standpoint, these studies were subjected to Trial Sequential Analysis to determine whether the pooled data were adequately powered to verify the study outcomes. On-demand treatment with PDE5Is was significantly better than daily treatment in recovering drug-assisted EF. This effect was maintained even when the drugs were stratified according with half-life. Although not based on head-to-head trials, Avanafil used on-demand was the most effective PDE5I in recovering drug-assisted EF. Whereas tadalafil was equally effective when used both on-demand and daily, vardenafil significantly improved drug-assisted EF recovery only when used on-demand. The start of PDE5I treatment six months or more after surgery compared to treatment started earlier did not negatively affect the rate of drug-assisted EF recovery or the possibility to have successful intercourse based on the Sexual Encounter Profile question-3 (SEP-3). Current trials do not support the hypothesis that PDE5I use recovers drug-unassisted EF, although chronic low-dose tadalafil administration may help to preserve erectile tissue integrity. Potential shortcomings in the trials design may partially explain these disappointing results and several questions concerning the recovery of drug-unassisted EF remain unanswered. Thus, there is a need for well-designed new RCTs requiring changes in the timing of PDE5I administration as well as in the dose and the treatment duration.

Influence of the patient-practitioner interaction context on acupuncture outcomes in functional dyspepsia: study protocol for a multicenter randomized controlled trial

BACKGROUND

In the treatment of functional dyspepsia, the placebo effect has been reported to be high, and the influence of the patient-practitioner relationship may be a major component of this effect. The specific and non-specific effects of acupuncture cannot be easily distinguished, and the patient-practitioner relationship may influence the total therapeutic effect in clinical practice. There have been no studies that investigate the influence of patient-practitioner relationship on acupuncture treatment for patients with functional dyspepsia.

METHODS

Patients with postprandial distress syndrome, a functional dyspepsia subtype, will be recruited at three hospitals (two in Korea and one in USA) for an international, multi-center, randomized, patient/assessor-blinded, clinical trial. The total anticipated sample size is 88. The participants will be randomly allocated into two groups: an augmented interaction group and a limited interaction group. Acupuncture, with total 12 acupoints, will be performed twice weekly for 4 weeks in both groups. Trained practitioners will provide an "augmented" or "limited" interaction context, as determined by random allocation. The primary outcome measure is the proportion of responders, the proportion of participants who answer "yes" to more than half of the adequate relief questions during the study. Secondary outcome measures include questionnaires for quality of life and symptoms of dyspepsia, and maximum tolerable volume of nutrient drink test. Data will be collected at baseline and following 4 weeks of acupuncture.

DISCUSSION

This study will evaluate the influence of the patient-practitioner interaction on clinical effects of acupuncture in patients with functional dyspepsia.

TRIAL REGISTRATION

CRIS Identifier: ( KCT0002229 ).

Placebo-related effects: a meta-narrative review of conceptualization, mechanisms and their relevance in rheumatology

For decades in medicine, the placebo effect has been conceptualized as a subjective psychological effect associated with an inert substance and considered to be a nuisance noise in the assessment of therapeutic effects in clinical trials. However, research on placebo has undergone substantial developments since the mid-1980s in several fields of knowledge (including methodology, psychology and neurosciences) that challenge this traditional view. Using a meta-narrative approach, this review of conceptualizations, determinants, mechanisms and models of placebo effects shows that placebo effects are genuine biopsychosocial phenomena strongly affected by context and factors surrounding the patient and treatments. Psychological experiments and neurobiological and neuroimaging studies have identified various types of placebo responses, driven by different mechanisms (especially but not only expectation and conditioning) and associated with different chemical, structural and functional features. Insights into the mechanisms involved in placebo responses have led to opportunities for ethical enhancements of these mechanisms in clinical practice, notably by improving the patient-doctor interaction and refining the therapeutic ritual. These developments should be carefully considered in rheumatology settings, in which placebo effects are both prevalent and significant, with the potential to improve patient care.

Open-label versus double-blind placebo treatment in irritable bowel syndrome: study protocol for a randomized controlled trial

BACKGROUND

Placebo medications, by definition, are composed of inactive ingredients that have no physiological effect on symptoms. Nonetheless, administration of placebo in randomized controlled trials (RCTs) and in clinical settings has been demonstrated to have significant impact on many physical and psychological complaints. Until recently, conventional wisdom has suggested that patients must believe that placebo pills actually contain (or, at least, might possibly contain) active medication in order to elicit a response to placebo. However, several recent RCTs, including patients with irritable bowel syndrome (IBS), chronic low back pain, and episodic migraine, have demonstrated that individuals receiving open-label placebo (OLP) can still experience symptomatic improvement and benefit from honestly described placebo treatment.

METHODS AND DESIGN

This paper describes an innovative multidisciplinary trial design (n = 280) that attempts to replicate and expand upon an earlier IBS OLP study. The current study will compare OLP to double-blind placebo (DBP) administration which is made possible by including a nested, double-blind RCT comparing DBP and peppermint oil. The study also examines possible genetic and psychological predictors of OLP and seeks to better understand participants' experiences with OLP and DBP through a series of extensive interviews with a randomly selected subgroup.

DISCUSSION

OLP treatment is a novel strategy for ethically harnessing placebo effects. It has potential to re-frame theories of placebo and to influence how physicians can optimize watch-and-wait strategies for common, subjective symptoms. The current study aims to dramatically expand what we know about OLP by comparing, for the first time, OLP and DBP administration. Adopting a unique, multidisciplinary approach, the study also explores genetic, psychological and experiential dimensions of OLP. The paper ends with an extensive discussion of the "culture" of the trial as well as potential mechanisms of OLP and ethical implications.

TRIAL REGISTRATION

ClinicalTrials.gov, identifier: NCT02802241 . Registered on 14 June 2016.

"Placebo effect is probably what we refer to as patient healing power": A qualitative pilot study examining how Norwegian complementary therapists reflect on their practice

BACKGROUND

Complementary therapists spend considerable time with their patients, especially in the first consultation. The communication between patients and their therapists is important for raising consciousness and activation of the patient's self-healing power. Thus, the aims in this study were to delineate what complementary therapists regard as essential in patient consultations, their view of the healing process, and how the therapists understand the placebo effect and its position in the healing process.

METHODS

Semi-structured individual interviews (n = 4), focus group interview (n = 1) and participant observation were conducted among four different complementary therapists in a Norwegian community. The text data was transcribed verbatim and the analysis of the material was conducted according to conventional and direct content analysis. Some codes were predefined and others were defined during the analysis.

RESULTS

The pilot study showed that the implemented methods seems feasible and fit well with the aims of this study. Complementary therapists (chiropractor, naprapath (musculoskeletal therapist), acupuncturist and acupuncturist/homeopath) representing four different complementary modalities participated. A combination of the conversation and examination during the first consultation formed the basis for the therapist's choice of treatment. A successful consultation was characterized by a fruitful relationship between the therapist and the patient. Moreover, the therapist needs to be humble and show the patient respect. Patients' positive beliefs and expectations about the treatment play a significant role in the healing process. The more hope the therapist can bring about, the more easily the patient can start believing that it is possible to get well.

CONCLUSION

This was a pilot study. Therefore the findings should be appreciated as limited and preliminary. Therapists' and patients' mutual understanding and treatment goals were essential for a successful consultation. The therapists emphasized their professional skills and therapeutic competence as important when building fruitful relationships with their patients. Exerting authority and making the patient feel confident were essential factors for a successful healing process. The complementary therapists understood the placebo effect as the patient's self-healing power, resulting from establishing trust and belief in the treatment process.

Effect of an orally formulated processed black cumin, from Iranian traditional medicine pharmacopoeia, in relieving symptoms of knee osteoarthritis: A prospective, randomized, double-blind and placebo-controlled clinical trial

AIM

Osteoarthritis is a global health problem, especially for the elderly. A good replacement for non-surgical treatments is the use of traditional medicines. We selected a revere plant (Nigella sativa L.), a widely utilized medicinal herb for the treatment of inflammatory conditions, from the Iranian traditional medicine (ITM) pharmacopoeia with proven anti-inflammatory and analgesic actions.

METHODS

We performed a prospective, randomized, double-blind, and placebo-controlled clinical trial, in order to investigate whether the herb is useful in alleviating the symptoms of knee osteoarthritis. American College of Rheumatology clinical criteria were the basis of diagnosis, while the Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire was considered as the main outcome measure. One hundred and ten eligible patients were assigned to receive a placebo or an active intervention (2 g/day of processed N. sativa seed powder in divided doses). Acetaminophen tablets were the rescue medicine. Finally, 40 patients in the placebo group and 37 patients in the active group completed the trial and were included in the statistical analysis.

RESULTS

Both cohorts demonstrated statistically significant within-group differences (P < 0.05) in some subscales that were more prominent in the active group without any considerable adverse effects. Nevertheless, KOOS score results and the mean number of acetaminophen tablets used by patients showed no statistically significant between-group differences.

CONCLUSIONS

It can be concluded that future programmed studies with larger sample sizes, longer follow-up periods, and other forms of N. sativa seeds as an active intervention is necessary to evaluate its efficacy in relieving the symptoms of knee osteoarthritis.

Does the model of additive effect in placebo research still hold true? A narrative review

Personalised and contextualised care has been turned into a major demand by people involved in healthcare suggesting to move toward person-centred medicine. The assessment of person-centred medicine can be most effectively achieved if treatments are investigated using ‘with versus without’ person-centredness or integrative study designs. However, this assumes that the components of an integrative or person-centred intervention have an additive relationship to produce the total effect. Beecher’s model of additivity assumes an additive relation between placebo and drug effects and is thus presenting an arithmetic summation. So far, no review has been carried out assessing the validity of the additive model, which is to be questioned and more closely investigated in this review.

Initial searches for primary studies were undertaken in July 2016 using Pubmed and Google Scholar. In order to find matching publications of similar magnitude for the comparison part of this review, corresponding matches for all included reviews were sought.

A total of 22 reviews and 3 clinical and experimental studies fulfilled the inclusion criteria. The results pointed to the following factors actively questioning the additive model: interactions of various effects, trial design, conditioning, context effects and factors, neurobiological factors, mechanism of action, statistical factors, intervention-specific factors (alcohol, caffeine), side-effects and type of intervention.

All but one of the closely assessed publications was questioning the additive model. A closer examination of study design is necessary. An attempt in a more systematic approach geared towards solutions could be a suggestion for future research in this field.

Comparison of the placebo effect between different non-penetrating acupuncture devices and real acupuncture in healthy subjects: a randomized clinical trial

Background

Several studies have used placebo acupuncture methods in recent years as a way for blinding therapeutic effect of acupuncture, however placebo method selection has not followed enough methodological criteria to the point of stabilishing a consensus of what should be the best method to be used. This study aimed to evaluate the effectiveness of three different placebo acupuncture methods for blinding applied in healthy subjects.

Methods

This study was approved by the Ethics Committee of the Federal University of Sergipe with the number 47193015.5.0000.5546 and all individuals participating in the study signed a free and informed consent. For this study, 321 healthy volunteers were randomly divided into seven groups using the abdominal point stomach (ST) 25 and seven groups using the lumbar point bladder (Bl) 52 for stimulation. For real acupuncture procedure, three different methods of placebo acupuncture plus a mix between real acupuncture and placebo applied in the same individual, totaling fourteen groups in this study. Outcome assessments were performed before and immediately after applying the technique. Investigator who assessed variables had no knowledgement about the method was applied. Identification, weight and height were measured before puncture by using. At the end, subjects were asked if they believed they were receiving real or placebo acupuncture.

Results

There was no significant difference between groups for the perception about the type o stimulation (wheter real or placebo puncture). Percentage of subjects who reported to have received real acupuncture in the abdominal point was 69.56% in real group, 86.95% in group Park Sham, 82.60% in needle + foam, 91.30% in insertion and removal, 78.26% in real + Park Sham, 86.36% in real + needle and foam, 86.95% in real + insertion and removal, and for the lumbar point was 86.36% in real group, 86.95% in group Park Sham, 69.56% in needle + foam, 72% in insertion and removal, 86.95% in real + Park Sham, 81.81% in real + needle and foam and 78.26% in real + insertion and removal.

Conclusion

All placebo acupuncture methods proposed in this study were equally effective for bliding the study participants using either abdominal or lumbar acupoints, and none of the placebo methods presented benefit compared to the other to be used in future clinical trials.

Ethics Committee

Federal University of Sergipe (UFS), number of approval: 47193015.5.0000.5546

Trial registration

ensaiosclinicos.gov.br RBR-3w2p32 Registered in 28th January 2016.

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.

Acupuncture for musculoskeletal pain: A meta-analysis and meta-regression of sham-controlled randomized clinical trials

The aims of this systematic review were to study the analgesic effect of real acupuncture and to explore whether sham acupuncture (SA) type is related to the estimated effect of real acupuncture for musculoskeletal pain. Five databases were searched. The outcome was pain or disability immediately (≤1 week) following an intervention. Standardized mean differences (SMDs) with 95% confidence intervals were calculated. Meta-regression was used to explore possible sources of heterogeneity. Sixty-three studies (6382 individuals) were included. Eight condition types were included. The pooled effect size was moderate for pain relief (59 trials, 4980 individuals, SMD -0.61, 95% CI -0.76 to -0.47; P < 0.001) and large for disability improvement (31 trials, 4876 individuals, -0.77, -1.05 to -0.49; P < 0.001). In a univariate meta-regression model, sham needle location and/or depth could explain most or all heterogeneities for some conditions (e.g., shoulder pain, low back pain, osteoarthritis, myofascial pain, and fibromyalgia); however, the interactions between subgroups via these covariates were not significant (P < 0.05). Our review provided low-quality evidence that real acupuncture has a moderate effect (approximate 12-point reduction on the 100-mm visual analogue scale) on musculoskeletal pain. SA type did not appear to be related to the estimated effect of real acupuncture.

The placebo effect in thyroid cancer: a meta-analysis

CONTEXT

The natural history of advanced thyroid malignancies is largely unknown. The outcome of patients included in the placebo arm of clinical trials could be reflective of their therapy-free evolution.

OBJECTIVE

To analyze the response rate, symptoms and adverse effects of locally advanced or metastatic differentiated (DTC) and medullary thyroid cancer (MTC) in patients treated with placebo in clinical trials.

DESIGN

PubMed (MEDLINE) and SCOPUS databases were searched through September 2015 to identify high-quality randomized controlled clinical trials. We included studies that recruited patients with DTC or MTC with a placebo arm.

METHODS

We conducted a meta-analysis for each category of response rate, adherence to treatment, and adverse events. An empirical Bayesian random-effect model was used.

RESULTS

We identified five clinical trials. DTC and MTC were independently analyzed. In the placebo arm, no complete response was observed; partial response occurred in 1.6% (0.6-3) and 6.4% (3.4-10.3) of DTC and MTC respectively; stable disease was described in 40.5% (34.6-46.9) and 53.9% (44.3-64.4) of DTC and MTC respectively. DTC reached a disease control rate of 42.3% (36.2-48.9) and MTC of 60.2 (50.1-71.4). Treatment discontinuation rate was 3.5% (1.9-5.5) in DTC and 5.7% (3.0-9.4) in MTC. Rate of dose reduction was 7.3% (4.8-10.5) in DTC and 6.2% (3.3-10.0) in MTC.

CONCLUSIONS

This meta-analysis provides extensive data on the response rate and adverse effects of locally advanced or metastatic DTC and MTC in patients treated with placebo. These results may be used for comparisons with results from clinical trials without a placebo arm.

Response to placebo in clinical epilepsy trials--Old ideas and new insights

Randomized placebo-controlled trials are a mainstay of modern clinical epilepsy research; the success or failure of innovative therapies depends on proving superiority to a placebo. Consequently, understanding what drives response to placebo (including the "placebo effect") may facilitate evaluation of new therapies. In this review, part one will explore observations about placebos specific to epilepsy, including the relatively higher placebo response in children, apparent increase in placebo response over the past several decades, geographic variation in placebo effect, relationship to baseline epilepsy characteristics, influence of nocebo on clinical trials, the possible increase in (SUDEP) in placebo arms of trials, and patterns that placebo responses appear to follow in individual patients. Part two will discuss the principal causes of placebo responses, including regression to the mean, anticipation, classical conditioning, the Hawthorne effect, expectations from symbols, and the natural history of disease. Included in part two will be a brief overview of recent advances using simulations from large datasets that have afforded new insights into causes of epilepsy-related placebo responses. In part three, new developments in study design will be explored, including sequential parallel comparison, two-way enriched design, time to pre-randomization, delayed start, and cohort reduction techniques.

Placebo by Proxy--the Influence of Parental Anxiety and Expectancy on Postoperative Morbidities in Children

BACKGROUND

Placebo effects emerging from expectancies of relatives, also known as placebo by proxy, is a rather unexplored field. In this study, we assume a correlation between parental anxiety/expectancy and postoperative morbidities in children. Accordingly, a reduction of parental anxiety is expected to enhance the effect of treatment.

METHODS

From October 2012 to June 2013, parents of 282 children completed a self-report closed-ended questionnaire embedded in a main RCT at three ambulatory care centers.

RESULTS

There were no significant associations between parental expectancy or anxiety and children experiencing vomiting and pain.

CONCLUSION

The present study is the first to investigate placebo by proxy in acupuncture treatment for children. The findings were not able to demonstrate any placebo effect by proxy. Unknown confounders and limitations of methods may have contributed to the negative findings. Thus, the findings must be read with precaution, as the possibility of a type II error cannot be excluded.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01729052.

Placebo effect in osteoarthritis: Why not use it to our advantage?

Osteoarthritis is a major cause of pain and reduced quality of life in the elderly, as well as a major economic burden. Unfortunately, there is no currently effective therapeutic strategy to prevent the progression of Osteoarthritis, and its treatment poses a great challenge to the medical community. Most of the treatment modalities currently available for osteoarthritis have small to moderate effect sizes, according to main meta-analyses and treatment guidelines. On the other hand, literature has demonstrated that placebo is considerably effective. The present article discusses the history of placebo effect and its scientific evidence, comments on ethical issues and provides insights about how it may be used to our advantage when treating osteoarthritic patients.

Genetics and the placebo effect: the placebome

Placebos are indispensable controls in randomized clinical trials (RCTs), and placebo responses significantly contribute to routine clinical outcomes. Recent neurophysiological studies reveal neurotransmitter pathways that mediate placebo effects. Evidence that genetic variations in these pathways can modify placebo effects raises the possibility of using genetic screening to identify placebo responders and thereby increase RCT efficacy and improve therapeutic care. Furthermore, the possibility of interaction between placebo and drug molecular pathways warrants consideration in RCT design. The study of genomic effects on placebo response, 'the placebome', is in its infancy. Here, we review evidence from placebo studies and RCTs to identify putative genes in the placebome, examine evidence for placebo-drug interactions, and discuss implications for RCTs and clinical care.