Hydrophobic residues in S1 modulate enzymatic function and voltage sensing in voltage-sensing phosphatase.

The voltage-sensing domain (VSD) is a four-helix modular protein domain that converts electrical signals into conformational changes, leading to open pores and active enzymes. In most voltage-sensing proteins, the VSDs do not interact with one another, and the S1-S3 helices are considered mainly scaffolding, except in the voltage-sensing phosphatase (VSP) and the proton channel (Hv). To investigate its contribution to VSP function, we mutated four hydrophobic amino acids in S1 to alanine (F127, I131, I134, and L137), individually or in combination. Most of these mutations shifted the voltage dependence of activity to higher voltages; however, not all substrate reactions were the same. The kinetics of enzymatic activity were also altered, with some mutations significantly slowing down dephosphorylation. The voltage dependence of VSD motions was consistently shifted to lower voltages and indicated a second voltage-dependent motion. Additionally, none of the mutations broke the VSP dimer, indicating that the S1 impact could stem from intra- and/or intersubunit interactions. Lastly, when the same mutations were introduced into a genetically encoded voltage indicator, they dramatically altered the optical readings, making some of the kinetics faster and shifting the voltage dependence. These results indicate that the S1 helix in VSP plays a critical role in tuning the enzyme's conformational response to membrane potential transients and influencing the function of the VSD.

A database of in situ water temperatures for large inland lakes across the coterminous United States.

Water temperature dynamics in large inland lakes are interrelated with internal lake physics, ecosystem function, and adjacent land surface meteorology and climatology. Models for simulating and forecasting lake temperatures often rely on remote sensing and in situ data for validation. In situ monitoring platforms have the benefit of providing relatively precise measurements at multiple lake depths, but are often sparser (temporally and spatially) than remote sensing data. Here, we address the challenge of synthesizing in situ lake temperature data by creating a standardized database of near-surface and subsurface measurements from 134 sites across 29 large North American lakes, with the primary goal of supporting an ongoing lake model validation study. We utilize data sources ranging from federal agency repositories to local monitoring group samples, with a collective historical record spanning January 1, 2000 through December 31, 2022. Our database has direct utility for validating simulations and forecasts from operational numerical weather prediction systems in large lakes whose extensive surface area may significantly influence nearby weather and climate patterns.

Using simulations to compare the current Davis Cup ranking system to Elo.

The Davis Cup is the premier men's team event in tennis, run by the International Tennis Federation and in which over 130 nations compete. It uses a merit-based ranking system that allows nations to gain a pre-determined number of points when they win. The rankings are integral to the competition structure and used in the draws of every round. Therefore, it is essential that the ranking method performs well with respect to required performance criteria of the International Tennis Federation. The Elo rating method is a commonly used method of rating and ranking participants in a competitive exercise and is used by FIFA for the ranking of male and female national teams. The performance of the current Davis Cup ranking method and Elo rating were compared using a simulation of the Davis Cup competition structure. Four criteria were used for the comparison: Finishing Order Correlation, Skill Level Correlation, Responsiveness, and Protection. Such a comparison has not previously been published. The two methods were comparable across three of the criteria, with the Davis cup easily outperforming Elo in responsiveness. Indeed, the Elo method had such poor responsiveness that improved performance may not be fully recognised within a player's career. An alternative method of optimising the Elo K-factor parameter was developed and this improved the performance of Elo to match the current Davis Cup method. In conclusion, the current Davis Cup ranking method is performing at a standard that cannot be matched by typically optimised Elo but can be matched when an alternative optimisation method is used. Therefore, no evidence was found to suggest that the current Davis Cup ranking method could be improved upon by using Elo. However, alternative K-factor optimisation methods should be considered when applying Elo to a competition.

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.

Placebos in pediatrics: A cross-sectional survey investigating physicians' perspectives.

OBJECTIVE: Placebo responses are significantly higher in children than in adults, suggesting a potential underused treatment option in pediatric care. To facilitate the clinical translation of these beneficial effects, we explored physicians' current practice, opinions, knowledge, and likelihood of recommending placebos in the future. METHODS: A cross-sectional web-based survey administered by REDCap was conducted at Boston Children's Hospital between October 2021 and March 2022. Physicians (n = 1157) were invited to participate through an email containing a link to a 23-item survey designed to assess physicians' attitudes and perceptions towards the clinical use of placebo in pediatrics. RESULTS: From 207 (18%) returned surveys, 109 (9%) were fully completed. Most respondents (79%) believed that enhancing the therapeutic components that contribute to the placebo response may be a way of improving pediatric care. However, whereas most (62%) found placebo treatments permissible, only one-third reported recommending them. In pediatrics, placebos are typically introduced as a medicine that "might help" (43%). The most common treatments recommended to enhance placebo effects are physical therapy, vitamins, and over-the-counter analgesics. Physicians most frequently recommend placebos for occasional pain, headaches, and anxiety disorders. Finally, the great majority of physicians (87%) stated they would be more likely to recommend placebo treatments if there were safety and ethical guidelines for open-label placebos. CONCLUSIONS: Placebo treatments seem permissible to physicians in pediatric care, but the development of safety and ethical guidelines may be necessary before physicians systematically incorporate the benefits of the placebo effect in pediatrics.

Brain-to-brain mechanisms underlying pain empathy and social modulation of pain in the patient-clinician interaction.

Social interactions such as the patient-clinician encounter can influence pain, but the underlying dynamic interbrain processes are unclear. Here, we investigated the dynamic brain processes supporting social modulation of pain by assessing simultaneous brain activity (fMRI hyperscanning) from chronic pain patients and clinicians during video-based live interaction. Patients received painful and nonpainful pressure stimuli either with a supportive clinician present (Dyadic) or in isolation (Solo). In half of the dyads, clinicians performed a clinical consultation and intake with the patient prior to hyperscanning (Clinical Interaction), which increased self-reported therapeutic alliance. For the other half, patient-clinician hyperscanning was completed without prior clinical interaction (No Interaction). Patients reported lower pain intensity in the Dyadic, relative to the Solo, condition. In Clinical Interaction dyads relative to No Interaction, patients evaluated their clinicians as better able to understand their pain, and clinicians were more accurate when estimating patients' pain levels. In Clinical Interaction dyads, compared to No Interaction, patients showed stronger activation of the dorsolateral and ventrolateral prefrontal cortex (dlPFC and vlPFC) and primary (S1) and secondary (S2) somatosensory areas (Dyadic-Solo contrast), and clinicians showed increased dynamic dlPFC concordance with patients' S2 activity during pain. Furthermore, the strength of S2-dlPFC concordance was positively correlated with self-reported therapeutic alliance. These findings support that empathy and supportive care can reduce pain intensity and shed light on the brain processes underpinning social modulation of pain in patient-clinician interactions. Our findings further suggest that clinicians' dlPFC concordance with patients' somatosensory processing during pain can be boosted by increasing therapeutic alliance.

Medical and social determinants of health as predictors of adverse outcomes in patients with inflammatory bowel disease.

There is a growing recognition that social determinants of health (SDOH) influence outcomes in patients with chronic diseases. This study aimed to investigate the influence of SDOH on outcomes in patients with inflammatory bowel disease (IBD). We conducted a retrospective cohort study of adult patients with IBD from 1996 to 2019. Patients were identified using ICD-10 codes for ulcerative colitis and Crohn's disease, and chart review was performed to validate the diagnosis and extract clinical information. SDOH factors including food security, financial resources, and transportation were self-reported by the patient. Random forest models were trained and tested in R to predict either IBD-related hospitalization or surgery. A total of 175 patients were studied, and the majority reported no financial resource, food security, or transportation concerns. For the model using clinical predictors, the sensitivity was 0.68 and specificity was 0.77 with an area under the receiver operating characteristic curve (AUROC) of 0.77. The model's performance did not significantly improve with the addition of SDOH information (AUROC of 0.78); however, model performance did vary by phenotype (AUROC of 0.86 for patients with Crohn's disease and AUROC of 0.68 for patients with ulcerative colitis). Further research is needed to understand the role of SDOH factors and IBD-related outcomes.

Psychological Predictors of Response to Open-Label Versus Double-Blind Placebo in a Randomized Controlled Trial in Irritable Bowel Syndrome.

OBJECTIVE: There is growing evidence that open-label placebo (OLP) may be an efficacious treatment of chronic and functional conditions. However, patient-level predictors of response to OLP have not been clearly identified. The aim of this study is to evaluate the psychological predictors of response to OLP and to compare this to double-blind placebo (DBP) and no-pill control (NPC). METHODS: This study is a secondary analysis of data collected in a 6-week randomized controlled trial evaluating placebo effects in irritable bowel syndrome (IBS). The primary outcome was change in IBS severity. Hierarchical linear regression identified predictors of placebo response in general and compared them between those randomized to OLP, DBP, and NPC. Predictor variables included personality traits, generalized anxiety, depression, visceral sensitivity (a measure of symptom-specific anxiety), and pain catastrophizing. RESULTS: A total of 210 participants (mean age = 42.3 years, 73.3% female) were included. Regression models revealed that visceral sensitivity was a predictor of response to OLP and NPC but not DBP. Interestingly, the effects were opposite, with high visceral sensitivity predicting less improvement in NPC and more improvement in OLP. Pain catastrophizing was a negative predictor of response to OLP (i.e., high pain catastrophizing was associated with less improvement in OLP). Neither visceral sensitivity nor pain catastrophizing played a significant role for response to DBP. CONCLUSIONS: IBS participants who score low on the Pain Catastrophizing Scale but high on the Visceral Sensitivity Index seem to benefit particularly from OLP. Our study suggests that different psychological mechanisms may be involved in DBP and OLP interventions.

Are They Side Effects? Extraintestinal Symptoms Reported During Clinical Trials of Irritable Bowel Syndrome May Be More Severe at Baseline.

BACKGROUND & AIMS: Many of the reported adverse events in clinical trials of irritable bowel syndrome are extraintestinal symptoms, which typically are assessed by open-ended questions during the trial and not at baseline. This may lead to misattribution of some pre-existing symptoms as side effects to the treatment. METHODS: The current study analyzed data from a 6-week clinical trial of irritable bowel syndrome. Participants were randomized to receive double-blind peppermint oil, double-blind placebo, or treatment as usual. Extraintestinal symptoms were assessed at baseline and at the end of the study. RESULTS: This analysis included 173 participants (30 received double-blind peppermint oil, 72 received treatment as usual, and 71 received double-blind placebo). At baseline, each group reported approximately 5 extraintestinal symptoms per participant. The number of symptoms per participant decreased to an average of 3 by the end-of-study visit, and this change was statistically significant in all groups (P < .001 for each group). When evaluating individual extraintestinal symptoms, the majority of participants did not report new/worse symptoms. In fact, between the baseline assessment and the final assessment, the average symptom severity decreased significantly in all 3 groups (P < .001). CONCLUSIONS: Our study suggests that participants with irritable bowel syndrome often experience extraintestinal symptoms at baseline and that these symptoms generally improve in severity over the course of a clinical trial, regardless of the treatment arm. Systematic assessment of extraintestinal symptoms at the beginning of a clinical trial is necessary to determine more definitively whether these symptoms may be considered an adverse event attributable to a study medication.

Effect of Open-label Placebo on Children and Adolescents With Functional Abdominal Pain or Irritable Bowel Syndrome: A Randomized Clinical Trial.

IMPORTANCE: Although it is widely believed that concealment or deception is required to elicit a placebo response, recent studies with adults suggest that open-label placebo (OLP) (ie, honestly prescribed placebos) can yield significant benefits. No studies of OLP have been performed with children. OBJECTIVE: To evaluate the efficacy of OLP for the treatment of children and adolescents with functional abdominal pain or irritable bowel syndrome. DESIGN, SETTING, AND PARTICIPANTS: This multicenter crossover randomized clinical trial was conducted from July 1, 2015, to June 15, 2018, at 3 US centers among children and adolescents aged 8 to 18 years with functional abdominal pain or irritable bowel syndrome defined per Rome III criteria. Statistical analysis was performed from March 1, 2019, to September 30, 2020, on an intention-to-treat basis. INTERVENTIONS: Patients completed 1 week of observation prior to randomization to 1 of 2 counterbalanced groups: OLP for 3 weeks followed by a 3-week control period or control period for 3 weeks followed by OLP for 3 weeks. During the OLP period, participants took 1.5 mL of an inert liquid placebo twice a day. A standardized method for explaining the OLP was used, and the interaction with clinicians had the same duration and style for both time periods. Hyoscyamine was allowed as a rescue medication. MAIN OUTCOMES AND MEASURES: The primary outcome was the mean daily pain score during each of the interventions, measured on a 0- to 100-mm visual analog scale, where higher scores indicated greater pain. The number of rescue medications taken during each intervention served as an objective secondary measure. RESULTS: Thirty patients (mean [SD] age, 14.1 [3.4] years; 24 female participants [80.0%]; 16 [53.3%] with functional abdominal pain and 14 [46.7%] with irritable bowel syndrome) completed the study. The mean (SD) pain scores were significantly lower during OLP treatment compared with the control period (39.9 [18.9] vs 45.0 [14.7]; difference, 5.2; 95% CI, 0.2-10.1; P = .03). Patients took nearly twice as many hyoscyamine pills during the control period compared with during the OLP period (mean [SD] number, 3.8 [5.1] pills vs 2.0 [3.0] pills; difference, 1.8 pills; 95% CI, 0.5-3.1 pills). CONCLUSIONS AND RELEVANCE: During OLP, patients with functional abdominal pain or irritable bowel syndrome reported significantly less pain and took significantly fewer pain medications. Open-label placebo may be an effective treatment for children and adolescents with functional abdominal pain or irritable bowel syndrome. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02389998.

Patient-clinician brain concordance underlies causal dynamics in nonverbal communication and negative affective expressivity.

Patient-clinician concordance in behavior and brain activity has been proposed as a potential key mediator of mutual empathy and clinical rapport in the therapeutic encounter. However, the specific elements of patient-clinician communication that may support brain-to-brain concordance and therapeutic alliance are unknown. Here, we investigated how pain-related, directional facial communication between patients and clinicians is associated with brain-to-brain concordance. Patient-clinician dyads interacted in a pain-treatment context, during synchronous assessment of brain activity (fMRI hyperscanning) and online video transfer, enabling face-to-face social interaction. In-scanner videos were used for automated individual facial action unit (AU) time-series extraction. First, an interpretable machine-learning classifier of patients' facial expressions, from an independent fMRI experiment, significantly distinguished moderately painful leg pressure from innocuous pressure stimuli. Next, we estimated neural-network causality of patient-to-clinician directional information flow of facial expressions during clinician-initiated treatment of patients' evoked pain. We identified a leader-follower relationship in which patients predominantly led the facial communication while clinicians responded to patients' expressions. Finally, analyses of dynamic brain-to-brain concordance showed that patients' mid/posterior insular concordance with the clinicians' anterior insula cortex, a region identified in previously published data from this study1, was associated with therapeutic alliance, and self-reported and objective (patient-to-clinician-directed causal influence) markers of negative-affect expressivity. These results suggest a role of patient-clinician concordance of the insula, a social-mirroring and salience-processing brain node, in mediating directional dynamics of pain-directed facial communication during therapeutic encounters.

Frequency of Adverse Events in the Placebo Arms of COVID-19 Vaccine Trials: A Systematic Review and Meta-analysis.

Importance: Adverse events (AEs) after placebo treatment are common in randomized clinical drug trials. Systematic evidence regarding these nocebo responses in vaccine trials is important for COVID-19 vaccination worldwide especially because concern about AEs is reported to be a reason for vaccination hesitancy. Objective: To compare the frequencies of AEs reported in the placebo groups of COVID-19 vaccine trials with those reported in the vaccine groups. Data Sources: For this systematic review and meta-analysis, the Medline (PubMed) and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched systematically using medical subheading terms and free-text keywords for trials of COVID-19 vaccines published up to July 14, 2021. Study Selection: Randomized clinical trials of COVID-19 vaccines that investigated adults aged 16 years or older were selected if they assessed solicited AEs within 7 days of injection, included an inert placebo arm, and provided AE reports for both the vaccine and placebo groups separately. Full texts were reviewed for eligibility by 2 independent reviewers. Data Extraction and Synthesis: Data extraction and quality assessment were performed independently by 2 reviewers, adhering to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline and using the Cochrane risk-of-bias tool. Meta-analyses were based on random-effects models. Main Outcomes and Measures: The primary outcomes were the proportions of placebo recipients reporting overall, systemic, and local (injection-site) AEs as well as logarithmic odds ratios (ORs) to evaluate group differences. Outcomes were tested for significance using z tests with 95% CIs. Results: Twelve articles with AE reports for 45 380 participants (22 578 placebo recipients and 22 802 vaccine recipients) were analyzed. After the first dose, 35.2% (95% CI, 26.7%-43.7%) of placebo recipients experienced systemic AEs, with headache (19.3%; 95% CI, 13.6%-25.1%) and fatigue (16.7%; 95% CI, 9.8%-23.6%) being most common. After the second dose, 31.8% (95% CI, 28.7%-35.0%) of placebo recipients reported systemic AEs. The ratio between placebo and vaccine arms showed that nocebo responses accounted for 76.0% of systemic AEs after the first COVID-19 vaccine dose and for 51.8% after the second dose. Significantly more vaccine recipients reported AEs, but the group difference for systemic AEs was small after the first dose (OR, -0.47; 95% CI, -0.54 to -0.40; P < .001; standardized mean difference, -0.26; 95% CI, -0.30 to -0.22) and large after the second dose (OR, -1.36; 95% CI, -1.86 to -0.86; P < .001; standardized mean difference, -0.75; 95% CI, -1.03 to -0.47). Conclusions and Relevance: In this systematic review and meta-analysis, significantly more AEs were reported in vaccine groups compared with placebo groups, but the rates of reported AEs in the placebo arms were still substantial. Public vaccination programs should consider these high rates of AEs in placebo arms.

Effect of antibiotic pretreatment on bacterial engraftment after Fecal Microbiota Transplant (FMT) in IBS-D.

Fecal microbiota transplantation (FMT) is an attractive strategy to correct microbial dysbiosis in diarrhea-predominant irritable bowel syndrome (IBS-D). Although the mechanism of FMT is thought to be bacterial engraftment, the best approach to achieve engraftment after FMT in IBS-D (and other diseases) is not clear. We evaluated the effect of FMT (with or without pretreatment with antibiotics) on gut microbiome and symptoms in patients with IBS-D. In this randomized, placebo-controlled, single-center study, 44 patients with IBS-D with a least moderate severity (IBS severity scoring system, i.e., IBS-SSS, ≥175) were randomly assigned to one of four groups: single-dose oral FMT alone, single-dose oral FMT following a 7-day pretreatment course of Ciprofloxacin and Metronidazole (CM-FMT) or Rifaximin (R-FMT), or Placebo FMT. Primary endpoint was engraftment post-FMT and secondary endpoints were changes in IBS-SSS, and IBS-quality of life (IBS-QOL) at week 10. Median engraftment was significantly different among the three FMT groups (P = .013). Engraftment post-FMT was significantly higher in the FMT alone arm (15.5%) compared to that in R-FMT group (5%, P = .04) and CM-FMT group (2.4%, P = .002). The mean change in IBS-SSS and IBS-QOL from baseline were not significantly different among the four groups or between the three FMT groups combined vs. placebo at week 10. In summary, antibiotic pretreatment significantly reduced bacterial engraftment after FMT in patients with IBS-D.

Improving Medication Tolerance: A Pilot Study in Disorders of Gut-brain Interaction Treated With Tricyclic Antidepressants.

OBJECTIVES: Tricyclic antidepressants (TCAs) are commonly used to treat disorders of gut-brain interaction (DGBI). However, these medications are often associated with side effects that lead to early treatment discontinuation. Research in other chronic medical conditions suggests that many TCA side effects may be caused by nocebo (negative placebo) effects. The current study tests a brief, verbal intervention aimed at improving tolerance of TCAs in DGBI by providing education about nocebo effects. MATERIALS AND METHODS: This pilot randomized controlled trial was performed in a tertiary care gastroenterology clinic. Participants with DGBI were randomized "standard information," describing the benefits and risks of TCAs, or "augmented information," which included an additional <30-second education about nocebo effects. Two weeks after their visit, participants were emailed a survey evaluating the number and bothersomeness of side effects, adequate relief, global improvement, and treatment satisfaction. RESULTS: Thirty-one patients were randomized and 22 responded to the survey. The average age was 40% and 59% were women. Although not statistically significant, the augmented group attributed nominally fewer symptoms to TCAs than the standard group, with a medium effect size (1.5 vs. 4.2, effect size d=0.56, P=0.212) and reported being significantly less bothered by those symptoms (13.4 vs. 38.1, P=0.037). A nominally larger percentage of the augmented group reported adequate relief of symptoms after 2 weeks of treatment compared with the standard group (55% vs. 27%, respectively). CONCLUSIONS: This pilot study demonstrates that a brief (≈30 s) clinical intervention addressing nocebo effects may improve tolerance of TCAs. These findings provide support for future, fully powered studies to evaluate the impact of framing on clinical outcomes, especially in chronic conditions.

Cangrelor in STEMI as a bridge to CABG- a mini-case series.

Background: Patients with STEMI receive dual antiplatelet therapy as soon as possible with aspirin and a P2Y12 receptor antagonist prior to PCI. A fraction of these patients may have multi-vessel disease needing emergent CABG surgery. The choice of a P2Y12 receptor antagonist plays a role in the timing of CABG surgery as it poses a bleeding risk until it is completely eliminated from the system. Oral P2Y12 receptor antagonists have a long duration of platelet inhibition which is difficult to reverse. Cangrelor is an intravenous P2Y12 receptor antagonist with a short half-life and rapid cessation of its effect after discontinuation. Methods: Three patients who presented to our emergency department with STEMI were started on cangrelor infusion prior to cardiac catheterization instead of other P2Y12 receptor antagonists like clopidogrel or ticagrelor. The study received ethical approval as it is part of the current standard of care for STEMI patients. Results: All three patients were found to have multi-vessel disease during coronary angiography requiring CABG surgery. As cangrelor was used in these patients they were able to have their surgery within 24-48 h. Intravenous cangrelor was stopped about an hour before surgery. No bleeding complications occurred and all three patients made a speedy recovery in the ICU. Conclusion: Cangrelor is a potent P2Y12 receptor antagonist which can be used in patients presenting with STEMI as one of the two anti-platelet agents along with aspirin without any dilemma that it would cause a delay in CABG surgery if the patients need one.

Peppermint Oil Treatment for Irritable Bowel Syndrome: A Randomized Placebo-Controlled Trial.

INTRODUCTION: Peppermint oil is often used to treat irritable bowel syndrome (IBS); however, the overall quality of previous studies is low, and findings have been heterogeneous. This study aimed to compare the effects of peppermint oil vs placebo in relieving IBS symptoms. METHODS: In a 6-week, randomized, double-blind, placebo-controlled trial at a single academic center in the United States, individuals diagnosed with IBS (Rome IV criteria), with moderate to severe symptoms based on the IBS Severity Scoring System (IBS-SSS score ≥175), were randomized to enteric-coated peppermint oil 180 mg 3 times daily vs placebo in a 1:2 ratio. The primary outcome was mean change in IBS-SSS scores from baseline to 6-week endpoint. RESULTS: A modified intent-to-treat analysis revealed that there were substantial mean improvements from baseline to 6-week endpoint in the main outcome measure (IBS-SSS) for both peppermint oil (90.8, SD = 75.3) and placebo (100.3, SD = 99.6). Although the peppermint oil group reported numerically lower improvement than the placebo group, the effect size was small (d = -0.11), and the difference between the groups was not statistically significant (P = 0.97). Similarly, both groups reported substantial improvements on the secondary endpoints; but again, there were no statistically significant differences between the groups on any of the secondary measures. Sensitivity analyses using multiple imputation to replace missing data produced similar results and revealed no significant differences between peppermint oil and placebo on any outcome measure. DISCUSSION: Peppermint oil and placebo both showed clinically meaningful improvement in IBS symptoms. However, there were no significant differences between the groups. Further large, rigorous trials are needed to evaluate the role of peppermint oil for the treatment of IBS.

Open-label placebo vs double-blind placebo for irritable bowel syndrome: a randomized clinical trial.

ABSTRACT: It is commonly believed that blinding to treatment assignment is necessary for placebos to have an effect. However, placebos administered without concealment (ie, open-label placebos [OLPs]) have recently been shown to be effective in some conditions. This study had 2 objectives: first, to determine whether OLP treatment is superior to no-pill control (NPC) in irritable bowel syndrome (IBS) and, second, to compare the efficacy of OLP against double-blind placebo (DBP). In a 6-week, 3-arm, randomized clinical trial, participants were randomized in equal proportions to 3 arms: OLP, DBP, or NPC. Two hundred sixty-two adults (72.9% women), with a mean age of 42.0 (SD = 18.1) years, participated in the primary study. The mean improvement on the IBS Severity Scoring System from baseline to the 6-week end point was significantly greater in OLP compared with that in NPC (90.6 vs 52.3, P = 0.038). Open-label placebo and DBP did not differ significantly on IBS Severity Scoring System improvement (100.3 vs 90.6, P = 0.485). Standardized effect sizes were moderate for OLP vs NPC (d = 0.43) and small for OLP vs DBP (d = 0.10). Participants treated with OLP reported clinically meaningful improvements in IBS symptoms that were significantly greater than those on NPC. Open-label placebo and DBP had similar effects that did not differ significantly, suggesting that blinding may not be necessary for placebos to be effective and that OLP could play a role in the management of patients with refractory IBS.

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.