Placebo effects and racial and ethnic health disparities: an unjust and underexplored connection

Opioids Diminish the Placebo Antidepressant Response: A Post Hoc Analysis of a Randomized Controlled Ketamine Trial

Background

The endogenous opioid system is thought to play a role in the placebo antidepressant response. A recent trial comparing the rapid antidepressant effects of ketamine versus placebo in surgical patients, some of whom were on chronic opioid therapy, revealed a substantial placebo effect. This finding provided an opportunity to test the hypothesis that opioid agonist exposure interacts with placebo antidepressant responses.

Methods

This post hoc analysis utilized data from a previously reported randomized, anesthesia-blinded, placebo-controlled trial of intravenous ketamine in depressed patients undergoing routine surgery. Mixed-effects models were used to determine whether baseline opioid use influenced antidepressant responses to the trial interventions, as measured by the Montgomery-Åsberg Depression Rating Scale (MADRS) over 1 to 14 days post-treatment.

Results

In the placebo arm, baseline opioid use was associated with a 10-point increase (95% CI: 0.81-19.4) in MADRS scores across all post-treatment time points, indicating worse depression in this subgroup. In an alternative model using percent change in MADRS scores, the difference between opioid users and non-users was 38.4% (95% CI: 8.59-68.2), with opioid users experiencing less improvement. For ketamine-treated participants, baseline opioid use did not significantly impact MADRS scores or the percent change in MADRS scores. Pain intensity was not a significant predictor of MADRS outcomes, and the correlation between post-treatment MADRS scores and pain intensity was negligible (R=0.12).

Limitations

This analysis was unregistered and conducted on a small sample; the findings need to be confirmed by prospective controlled studies.

Conclusions

Opioid use at baseline attenuated the placebo antidepressant response independently of pain in depressed patients who received the study treatment under general anesthesia for routine surgery. The antidepressant response was preserved in opioid users who received intravenous ketamine.

Difelikefalin in Black/African American Hemodialysis Patients with Moderate-to-Severe Pruritus: Post hoc Analysis of KALM-1 and KALM-2

INTRODUCTION

Black and African American (AA) people are over-represented in the kidney failure population; therefore, the safety and efficacy of difelikefalin in Black/AA patients was evaluated.

METHODS

This was a post hoc, pooled exploratory subgroup analysis of the Phase 3 KALM-1 and -2 studies. Patients undergoing hemodialysis (HD) who had moderate-to-severe chronic kidney disease-associated pruritus (CKD-aP) at enrollment were stratified into self-reported Black/AA or White subgroups. Patients were randomized (1:1) to receive intravenous (IV) difelikefalin 0.5 µg/kg or placebo for 12 weeks. Difelikefalin efficacy was assessed with validated patient-reported outcome questionnaires: 24-h Worst Itch Numerical Rating Scale (WI-NRS), 5-D itch, and Skindex‑10.

RESULTS

There were 249 (29.3%) patients from the KALM studies that self-identified as Black/AA (n = 135 difelikefalin; n = 114 placebo). Clinically meaningful (≥3-point) reduction in WI-NRS score was achieved by 47.9% of Black/AA patients with difelikefalin versus 24.6% with placebo (p < 0.001). More Black/AA patients achieved a ≥5-point 5-D itch total improvement (54.9% vs. 35.7%; p = 0.013) and a ≥15-point Skindex-10 score improvement with difelikefalin versus placebo (49.0% vs. 28.9%; p = 0.006) compared with White patients. Incidence of treatment-emergent adverse events (TEAEs) was higher for Black/AA patients (difelikefalin: 78.5%; placebo: 70.8%) versus White patients (difelikefalin: 64.8%; placebo: 61.8%).

CONCLUSION

In this post hoc analysis, difelikefalin was efficacious in the Black/AA population and had an acceptable safety profile.

SIO-ASCO guideline on integrative medicine for cancer pain management: implications for racial and ethnic pain disparities

Racial and ethnic disparities in pain management pose major challenges to equitable cancer care delivery. These disparities are driven by complex interactions between patient-, provider-, and system-related factors that resist reductionistic solutions and require innovative, holistic approaches. On September 19, 2022, the Society for Integrative Oncology and the American Society of Clinical Oncology published a joint guideline to provide evidence-based recommendations on integrative medicine for cancer pain management. Integrative medicine, which combines conventional treatments with complementary modalities from cultures and traditions around the world, are uniquely equipped to resonate with diverse cancer populations and fill existing gaps in pain management. Although some complementary modalities, such as music therapy and yoga, lack sufficient evidence to make a specific recommendation, other modalities, such as acupuncture, massage, and hypnosis, demonstrated an intermediate level of evidence, resulting in moderate strength recommendations for their use in cancer pain management. However, several factors may hinder real-world implementation of the Society for Integrative Oncology and the American Society of Clinical Oncology guideline and must be addressed to ensure equitable pain management for all communities. These barriers include, but are not limited to, the lack of insurance coverage for many complementary therapies, the limited diversity and availability of complementary therapy providers, the negative social norms surrounding complementary therapies, the underrepresentation of racial and ethnic subgroups in the clinical research of complementary therapies, and the paucity of culturally attuned interventions tailored to diverse individuals. This commentary examines both the challenges and the opportunities for addressing racial and ethnic disparities in cancer pain management through integrative medicine.

‘It's not my greengrocer, it's someone from the medical profession’: A qualitative study regarding acceptability of deceptive and open‐label placebo prescribing in France

OBJECTIVES

To explore participants' views regarding clinical use of deceptive placebo (DP) and open-label placebo (OLP) treatments.

DESIGN

Qualitative thematic analysis.

METHODS

We conducted eight semi-structured interviews with healthy participants in an experimental trial comparing the efficacy of OLP and DP (Clinical trials n°NCT03934138). Interviewees' opinions were solicited following administration of placebos during the trial. Interviews were analysed using data-driven analysis.

RESULTS

We identified three themes. First, participants considered trust central in judging a placebo treatment to be acceptable. They expressed the importance of an implicit trust both in their health care professionals' (HCPs') competency as well as in the profession at large. A second theme was the perception of how placebo treatments might solve health problems. Acceptability of both types of placebo treatments was dependent on the perception patients had about the treatment solving their problem and/or doubts regarding the effectiveness of placebos The third theme encompassed perceived risks associated with placebo prescribing. Some comments viewed placebos positively as facilitating reduced medication intake. However, participants also identified the potential of placebos to generate adverse side effects.

CONCLUSIONS

Treatment acceptability by patients is a pre-requisite, alongside effectiveness, to harness OLPs in clinical care. Our study identified the importance of trust in HCPs prescribing placebos, the clinical effectiveness of placebos and the potential risks of these interventions in assessing their acceptability. Future research is needed to explore the contexts in which placebos might be used, and how best to communicate information about placebo interventions.

Sharing online clinical notes with patients: implications for nocebo effects and health equity

Patients in around 20 countries worldwide are now offered online access to at least some of their medical records. Access includes test results, medication lists, referral information, and/or the very words written by clinicians (so-called 'open notes'). In this paper, I discuss the possibility of one unintended negative consequence of patient access to their clinical notes-the potential to increase 'nocebo effects'. A growing body of research shows that nocebo effects arise by engaging perceptual and cognitive processes that influence negative expectancies, and as a consequence, adverse health effects. Studies show that increased awareness about the side effects of medications, the framing of information and the socioemotional context of care can increase the risk of nocebo effects. Connecting research into the nocebo effect with open notes provides preliminary support for the hypothesis that patient access to clinical notes might be a forum for facilitating unwanted nocebo effects. Furthermore, current findings indicate that we might expect to see systematic differences in how nocebo effects are experienced among different patient populations. The ethical implications of the tension between transparency and the potential for harm are discussed, with an emphasis on what open notes might mean for justice and equity in clinical care for a range of already marginalised patient populations. I argue that to resolve these challenges does not thereby justify 'closed notes', and conclude with suggestions for how health systems and clinicians might adapt to this innovation to reduce the risk of potential nocebo effects arising via this novel route.

Open notes in patient care: confining deceptive placebos to the past?

Increasing numbers of health organisations are offering some or all of their patients access to the visit notes housed in their electronic health records (so-called 'open notes'). In some countries, including Sweden and the USA, this innovation is advanced with patients using online portals to access their clinical records including the visit summaries written by clinicians. In many countries, patients can legally request copies of their records; however, open notes are different because this innovation offers patients rapid, real-time access via electronic devices. In this brief report, we explore what open notes might mean for placebo use in clinical care. Survey research into patient access to their clinical notes shows that increased transparency enhances patients' understanding about their medications and augments engagement with their care. We reflect on the consequences of access for placebo prescribing, particularly for the common practice of deceptive placebo use, in which patients are not aware they are being offered a placebo. In addition, we explore how open notes might facilitate placebo and nocebo effects among patients. Bridging placebo studies with medical ethics, we identify a range of empirical research gaps that now warrant further study.

Migraine history and response to lasmiditan across racial and ethnic groups

OBJECTIVE

The robust enrollment in SPARTAN and SAMURAI provided the opportunity to present post-hoc descriptive details on migraine disease characteristics and treatment outcomes after treatment with lasmiditan, a selective serotonin (5-HT_1F) receptor agonist, in racial and ethnic subgroups.

METHODS

Descriptive data from racial (White [W](n = 3471) and Black or African American [AA](n = 792)) and ethnic (Hispanic or Latinx [HL](n = 775) and Non-Hispanic or Latinx [Non-HL](n = 3637)) populations are presented on pooled data from two double-blind, placebo-controlled, randomized Phase 3 studies (SAMURAI [NCT02439320] and SPARTAN [NCT2605174]). Patients were treated with lasmiditan (50 (SPARTAN only), 100, or 200 mg) or placebo for a single migraine attack of moderate-to-severe intensity. Efficacy data were recorded in an electronic diary at baseline, 30, 60, 90, and 120 min. Safety was evaluated and reported by occurrences of adverse events.

RESULTS

Clinical characteristics were generally similar across populations. W participants had longer migraine history than AA participants, and Non-HL participants had more migraine disability than HL participants. In the lasmiditan single-attack studies, AA participants waited longer than W participants to take study drug. A higher proportion of HL participants rated baseline migraine severity as severe compared to Non-HL participants. Response to lasmiditan was similar across racial and ethnic groups, including pain response, freedom from most bothersome symptom and migraine-related disability, and safety and tolerability. Across multiple outcomes, AA and HL participants tended to report more positive outcomes.

CONCLUSIONS

There were few differences in demographic and clinical characteristics across racial and ethnic groups. Similar lasmiditan efficacy and safety outcomes were observed in AA versus W participants, and in HL versus Non-HL participants. Small observed differences may be driven by a tendency toward a more positive response observed across all treatment groups by AA and HL participants.

What Do Placebo and Nocebo Effects Have to Do With Health Equity? The Hidden Toll of Nocebo Effects on Racial and Ethnic Minority Patients in Clinical Care

A placebo effect is a positive clinical response to non-specific elements of treatment with a sham or inert replica of a drug, device, or surgical intervention. There is considerable evidence that placebo effects are driven by expectation of benefit from the intervention. Expectation is shaped by a patient's past experience, observations of the experience of others, and written, verbal, or non-verbal information communicated during treatment. Not surprisingly, expectation in the clinical setting is strongly influenced by the attitude, affect, and communication style of the healthcare provider. While positive expectations can produce beneficial effects, negative information and experiences can lead to negative expectations, and consequently negative or nocebo effects. Key components identified and studied in the placebo and nocebo literature intersect with factors identified as barriers to quality care in the clinical setting for Black patients and other patients of color, including poor patient-clinician communication, medical mistrust, and perceived discrimination. Thus, in the context of discrimination and bias, the absence of placebo and presence of nocebo-generating influences in clinical settings could potentially reinforce racial and ethnic inequities in clinical outcomes and care. Healthcare inequities have consequences that ripple through the medical system, strengthening adverse short- and long-term outcomes. Here, we examine the potential for the presence of nocebo effects and absence of placebo effects to play a role in contributing to negative outcomes related to unequal treatment in the clinical encounter.

Diverse predictors of treatment response to active medication and placebo in gambling disorder

Gambling disorder creates a significant public health burden. Despite decades of clinical trials, there are no licensed pharmacological treatments for gambling disorder. Contributing factors to this are the high placebo response rates seen in clinical trials, the heterogeneity of the disorder and high rates of psychiatric comorbidities. Indeed, a number of demographic and clinical variables have previously been associated with altered responses to pharmacotherapy, psychotherapy and placebo. Which variables are likely to predict response to one modality over another remains uncertain. We carried out multiple linear regression analyses in a pooled dataset from six treatment studies in gambling disorder with the aim of identifying predictors of treatment response. Potential predictors were identified a priori through hypothesis and entered into models including all patients, and subsequently for those randomized to active medication or placebo separately. We found that baseline severity of gambling symptoms and number of weeks completed in a trial were predictors of active medication response, while decreased baseline symptoms of anxiety, increased baseline symptoms of depression, and non-Caucasian ethnicity were associated with placebo response. Sensitivity analyses showed that these associations were robust to choices made during the analysis. Further research is required to understand whether controlling for these variables, or using enriched samples, improves assay sensitivity in placebo-controlled clinical trials for gambling disorder.

What Should Clinicians Tell Patients about Placebo and Nocebo Effects? Practical Considerations Based on Expert Consensus

INTRODUCTION

Clinical and laboratory studies demonstrate that placebo and nocebo effects influence various symptoms and conditions after the administration of both inert and active treatments.

OBJECTIVE

There is an increasing need for up-to-date recommendations on how to inform patients about placebo and nocebo effects in clinical practice and train clinicians how to disclose this information.

METHODS

Based on previous clinical recommendations concerning placebo and nocebo effects, a 3-step, invitation-only Delphi study was conducted among an interdisciplinary group of internationally recognized experts. The study consisted of open- and closed-ended survey questions followed by a final expert meeting. The surveys were subdivided into 3 parts: (1) informing patients about placebo effects, (2) informing patients about nocebo effects, and (3) training clinicians how to communicate this information to the patients.

RESULTS

There was consensus that communicating general information about placebo and nocebo effects to patients (e.g., explaining their role in treatment) could be beneficial, but that such information needs to be adjusted to match the specific clinical context (e.g., condition and treatment). Experts also agreed that training clinicians to communicate about placebo and nocebo effects should be a regular and integrated part of medical education that makes use of multiple formats, including face-to-face and online modalities.

CONCLUSIONS

The current 3-step Delphi study provides consensus-based recommendations and practical considerations for disclosures about placebo and nocebo effects in clinical practice. Future research is needed on how to optimally tailor information to specific clinical conditions and patients' needs, and on developing standardized disclosure training modules for clinicians.

A 36-week multicenter, randomized, double-blind, placebo-controlled, parallel-group, phase 3 clinical trial of sodium oligomannate for mild-to-moderate Alzheimer's dementia

BACKGROUND

New therapies are urgently needed for Alzheimer's disease (AD). Sodium oligomannate (GV-971) is a marine-derived oligosaccharide with a novel proposed mechanism of action. The first phase 3 clinical trial of GV-971 has been completed in China.

METHODS

We conducted a phase 3, double-blind, placebo-controlled trial in participants with mild-to-moderate AD to assess GV-971 efficacy and safety. Participants were randomized to placebo or GV-971 (900 mg) for 36 weeks. The primary outcome was the drug-placebo difference in change from baseline on the 12-item cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-cog12). Secondary endpoints were drug-placebo differences on the Clinician's Interview-Based Impression of Change with caregiver input (CIBIC+), Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL) scale, and Neuropsychiatric Inventory (NPI). Safety and tolerability were monitored.

RESULTS

A total of 818 participants were randomized: 408 to GV-971 and 410 to placebo. A significant drug-placebo difference on the ADAS-Cog12 favoring GV-971 was present at each measurement time point, measurable at the week 4 visit and continuing throughout the trial. The difference between the groups in change from baseline was - 2.15 points (95% confidence interval, - 3.07 to - 1.23; p < 0.0001; effect size 0.531) after 36 weeks of treatment. Treatment-emergent adverse event incidence was comparable between active treatment and placebo (73.9%, 75.4%). Two deaths determined to be unrelated to drug effects occurred in the GV-971 group.

CONCLUSIONS

GV-971 demonstrated significant efficacy in improving cognition with sustained improvement across all observation periods of a 36-week trial. GV-971 was safe and well-tolerated.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT0229391 5. Registered on November 19, 2014.

The Importance of Patient Expectations: A Mixed-Methods Study of U.S. Psychiatrists

Objective: To examine how psychiatrists think about and modulate non-specific factors (e.g., hope, expectations) in clinical practice. Methods: U.S. psychiatrists were recruited for two studies assessing attitudes and behaviors related to non-specific factors. Study 1 entailed remote qualitative focus groups (k = 7) with n = 26 participants (36.0% female). Study 2 was a quantitative survey with n = 346 respondents (34.0% female) designed to assess the generalizability of focus group findings. Results: Four themes were identified in Study 1 that were used to inform the survey (Study 2): (1) Expectations (2) Hope, (3) Placebo Effect, and (4) Aesthetic Features. Nearly all surveyed psychiatrists (92.2%) considered patient expectations at least "most of the time" when interacting with a patient. Focus groups revealed that psychiatrists often attempt to balance optimism and realism to improve outcomes. A majority of survey respondents believed office design and physician attire could at least somewhat influence expectations (72.5 and 77.3%, respectively) and even outcomes (51.5 and 58.7%, respectively). Focus group psychiatrists described how physical features may be used as therapeutic tools. Conclusions: Psychiatrists are highly mindful of patient expectations. Although there is variability in the perceived importance of expectations, hope, the placebo effect, and aesthetic features, many utilize these factors in clinical practice.

Open-Label Placebo Trial among Japanese Patients with Chronic Low Back Pain

Background

The aim of this study was to confirm the effectiveness of open-label placebo (OLP) in Japanese patients with chronic low back pain (CLBP), similar to previous reports, and to investigate its short- and medium-term effects in this study population.

Methods

Fifty-two patients with CLBP were randomized into a treatment as usual (TAU) group (n = 26) or an OLP + TAU group (n = 26) for 12 weeks. The TAU included advice to remain active and exercise in conjunction with recent psychological education based on a self-management strategy. In contrast, participants in the OLP + TAU group were instructed to take two OLP capsules a day. Outcome measures were assessed at baseline and at weeks 3 and 12 using the Roland–Morris Disability Questionnaire (RMDQ), Numerical Rating Scale (NRS) for pain intensity, and the Timed-Up-and-Go (TUG) test. Difference in outcomes between the two groups was compared at the two follow-up points.

Results

Although all participants completed the 3-week follow-up, four patients (two in each group) were lost to follow-up beyond week 3. There were no significant intergroup differences in changes in the RMDQ score (p=0.40), pain-NRS score (p=0.19), and TUG time (p=0.98) at week 3. Two-way repeated measure analyses of covariance showed significant time-course effects but did not show group effects or any interactions between the time-course and group in terms of the RMDQ score. However, it did not show any effects in the pain-NRS score and TUG time at week 12.

Conclusions

The OLP + TAU group showed no superior findings in comparison with the TAU group after 3 weeks and 12 weeks for Japanese patients with CLBP. Nonetheless, significant improvements in functional disability were observed in both groups.

More than consent for ethical open-label placebo research

Recent studies have explored the effectiveness of open-label placebos (OLPs) for a variety of conditions, including chronic pain, cancer-related fatigue and irritable bowel syndrome. OLPs are thought to sidestep traditional ethical worries about placebos because they do not involve deception: with an OLP, patients or subjects are told outright that they are not given an active substance. As deception is framed as the primary hurdle to ethical placebo use, the door is ostensibly opened to ethical studies of OLPs. In this article, I suggest that even though OLPs seemingly do not involve deception, there are other ethical considerations in their clinical investigation and subsequent use. Research ethics often focusses on informed consent-of which, deception and honesty are a piece-as a means to justify research practices with human subjects. Yet, it is but one of the ethical considerations that should be taken into account. With research into placebo effects in particular, I argue that the history of clinical placebo use grounds special considerations for OLP research that go beyond respect for the autonomy of individual patients through informed consent and encompass structural concerns about the type of patient for whom a placebo has historically been thought appropriate.

Putting the 'Art' Into the 'Art of Medicine': The Under-Explored Role of Artifacts in Placebo Studies

Research in social psychology demonstrates that physical environmental factors – or “artifacts” such as provider clothing and office décor – can influence health outcomes. However, the role of artifacts in augmenting or diminishing health outcomes is under-explored in the burgeoning discipline of placebo studies. In this paper, we argue that a careful consideration of artifacts may carry significant potential in informing how placebo effects can be maximized, and nocebo effects minimized in clinical settings. We discuss the potential mechanisms, including classical conditioning, response expectancy, and mindsets, by which artifacts might enhance or diminish these effects. Next, we propose testable hypotheses to investigate how placebo and nocebo effects might be elicited by artifacts in care settings, and conclude by providing innovative research designs to advance this novel research agendum.

International Cross-Sectional Study on the Effectiveness of Okada Purifying Therapy, a Biofield Therapy, for the Relief of Various Symptoms

Objective: To investigate whether differences exist in the effectiveness/safety of a single session of Okada Purifying Therapy (OPT), a type of biofield therapy, among those from different ethnicity/cultures, and to analyze factors associated with the outcomes in a real-world setting.

Design: Pre–post test design using convenience sampling methods.

Setting: Home setting.

Subjects: A total of 11,303 individuals aged 16 years or older from 14 different countries (>1000 individuals each from Japan, the United States, Thailand, Chile/Peru, and <200 individuals each from Portugal, Spain, Argentina, Mexico, Brazil, South Korea, Taiwan, Belgium, and France). More than 50% of the subjects were themselves OPT practitioners, and more than 50% of the treatments were administered in an environment where the practice of OPT was promoted.

Intervention: Participants received a single session of OPT lasting 30 min or longer from the volunteer practitioners. They self-reported the changes in overall symptoms, physical pain, anxiety/depression, and dizziness/palpitation.

Outcome measures: Improvement/exacerbation rates of each symptom and factors associated with symptom improvement were analyzed.

Results: Of the participants, 77.5%, 75.6%, 78.4%, and 73.8% reported an improvement of overall symptoms, physical pain, anxiety/depression, and dizziness/palpitation, respectively. The improvement rates were consistently higher among participants from Chile/Peru than those from Japan, the United States, and Thailand (p < 0.001), and among those who had received a longer therapy (p < 0.001). Spanish/Portuguese speaking countries almost always showed high improvement rates; conversely, Japan showed a lower rate in each symptom. Participants' gender, reasons for participation, previous experience, and location of the session were also associated with the improvement of different symptoms. These findings occurred regardless of the participants' age or presence/absence of illness. In terms of safety, the exacerbation rates of symptoms were 2.8%, 2.5%, 0.8%, and 1.7%, respectively. Of those who expressed symptoms exacerbation, 71.6% recovered in a few hours. None of them needed emergency medical treatment.

Conclusions: In those who were often sympathetic to OPT and/or in an authorized location, OPT was effective and safe across countries with ethnic/cultural differences; however, participants' country of residence and duration of the session were independently associated with the changes in various symptoms. (ClinicalTrials.gov NCT03994809).

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.

Primary care providers' use of and attitudes towards placebos: An exploratory focus group study with US physicians

OBJECTIVE

To examine how primary care physicians define placebo concepts, use placebos in clinical practice, and view open-label placebos (OLPs).

DESIGN

Semi-structured focus groups that were audio-recorded and content-coded.

METHODS

Two focus groups with a total of 15 primary care physicians occurred at medical centres in the New England region of the United States. Prior experience using placebo treatments and attitudes towards open-label placebos were explored. Themes were analysed using an inductive data-driven approach.

RESULTS

Physicians displayed a nuanced understanding of placebos and placebo effects in clinical contexts which sometimes focused on relational factors. Some respondents reported that they prescribed treatments with no known pharmacological effect for certain conditions and symptoms ('impure placebos') and that such prescriptions were more common for pain disorders, functional disorders, and medically unexplained symptoms. Opinions about OLP were mixed: Some viewed OLPs favourably or considered them 'harmless'; however, others strongly rejected OLPs as disrespectful to patients. Other issues in relation to OLPs included the following: lack of guidelines, legal and reputational concerns, and the notion that such treatments would run counter to customary medical practice.

CONCLUSIONS

A number of physicians reported prescribing impure placebos in clinical care. Although some primary care physicians were resistant to the possibility of recommending OLPs, others regarded OLPs more favourably, viewing them as potential treatments, albeit with restricted potential. Statement of contribution What is already known? Many physicians report prescribing drugs for the purposes of eliciting a placebo effect. Initial evidence for the efficacy of open-label placebos is promising. What does this study add? A more nuanced description of the circumstances under which primary care physicians report placebo prescribing. A qualitative account of physician attitudes about using open-label placebos in clinical practice.

Ethnic Differences in Experimental Pain Responses Following a Paired Verbal Suggestion With Saline Infusion: A Quasiexperimental Study

BACKGROUND

Ethnic differences in placebo and nocebo responses are an important, yet underresearched, patient factor that might contribute to treatment disparities.

PURPOSE

The purpose of this study was to examine ethnic differences in pain trajectories following a verbal suggestion paired with a masked, inert substance (i.e., saline).

METHODS

Using a quasiexperimental design, we examined differences between 21 non-Hispanic Black (NHB) participants and 20 non-Hispanic White (NHW) participants in capsaicin-related pain rating trajectories following a nondirectional verbal suggestion + saline infusion. All participants were told that the substance would "either increase pain sensation, decrease it, or leave it unchanged." A spline mixed model was used to quantify the interaction of ethnicity and time on ratings.

RESULTS

There was a significant Ethnicity × Time interaction effect (β = -0.28, p = .002); NHB individuals reported significantly greater increases in pain following, but not before, the verbal suggestion + saline infusion. Sensitivity analyses showed no change in primary results based on differences in education level, general pain sensitivity, or condition order.

CONCLUSIONS

The present results showed ethnic differences in pain response trajectories following a verbal suggestion + saline infusion and suggest that future research rigorously examining possible ethnic differences in placebo/nocebo responses is warranted.

When Your Doctor "Gets It" and "Gets You": The Critical Role of Competence and Warmth in the Patient-Provider Interaction

Background: Research demonstrates that the placebo effect can influence the effectiveness of medical treatments and accounts for a significant proportion of healing in many conditions. However, providers may differ in the degree to which they consciously or unconsciously leverage the forces that produce placebo effects in clinical practice. Some studies suggest that the manner in which providers interact with patients shapes the magnitude of placebo effects, but this research has yet to distill the specific dimensions of patient-provider interactions that are most likely to influence placebo response and the mechanisms through which aspects of patient-provider interactions impact placebo response. Methods: We offer a simplifying and unifying framework in which interactions that boost placebo response can be dissected into two key dimensions: patients' perceptions of competence, or whether a doctor "gets it" (i.e., displays of efficiency, knowledge, and skill), and patients' perceptions of warmth, or whether a doctor "gets me" (i.e., displays of personal engagement, connection, and care for the patient). Results: First, we discuss how this framework builds on past research in psychology on social perception of competence and warmth and in medical literature on models of effective medical care, patient satisfaction, and patient-provider interactions. Then we consider possible mechanisms through which competence and warmth may affect the placebo response in healthcare. Finally, we share original data from patients and providers highlighting how this framework applies to healthcare. Both patient and provider data illustrate actionable ways providers can demonstrate competence and warmth to patients. Discussion: We conclude with recommendations for how researchers and practitioners alike can more systematically consider the role of provider competence and warmth in patient-provider interactions to deepen our understanding of placebo effects and, ultimately, enable providers to boost placebo effects alongside active medications (i.e., with known medical ingredients) and treatment in clinical care.

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.

Placebo hypoalgesia: above and beyond expectancy and conditioning

Placebo hypoalgesia provides pain relief for individuals via the expectation of a beneficial or therapeutic outcome, while nocebo hyperalgesia results in increased pain in response to anxious anticipation of harmful outcomes. These forms of placebo pain modulation can be induced through repeated associations, verbal cues, and social interactions. Understanding these methods of pain modulation can provide greater insight into the psychosocial contexts of pain modulation, as well as develop novel approaches to pain management.