Different contexts, different pains, different experiences

Placebo treatment affects brain systems related to affective and cognitive processes, but not nociceptive pain

Drug treatments for pain often do not outperform placebo, and a better understanding of placebo mechanisms is needed to improve treatment development and clinical practice. In a large-scale fMRI study (N = 392) with pre-registered analyses, we tested whether placebo analgesic treatment modulates nociceptive processes, and whether its effects generalize from conditioned to unconditioned pain modalities. Placebo treatment caused robust analgesia in conditioned thermal pain that generalized to unconditioned mechanical pain. However, placebo did not decrease pain-related fMRI activity in brain measures linked to nociceptive pain, including the Neurologic Pain Signature (NPS) and spinothalamic pathway regions, with strong support for null effects in Bayes Factor analyses. In addition, surprisingly, placebo increased activity in some spinothalamic regions for unconditioned mechanical pain. In contrast, placebo reduced activity in a neuromarker associated with higher-level contributions to pain, the Stimulus Intensity Independent Pain Signature (SIIPS), and affected activity in brain regions related to motivation and value, in both pain modalities. Individual differences in behavioral analgesia were correlated with neural changes in both modalities. Our results indicate that cognitive and affective processes primarily drive placebo analgesia, and show the potential of neuromarkers for separating treatment influences on nociception from influences on evaluative processes.

Overview: Chronic Pain and Cannabis-Based Medicines

Chronic pain is primarily conceptualized as a disease in its own right when it is associated with emotional distress and functional impairment. Pathophysiologically, dysfunction of the cortico-mesolimbic connectome is of major importance, with overlapping signals in the nociceptive and stress systems. The endocannabinoid system plays an important role in the central processing of nociceptive signals and regulates the central stress response. Clinically, there is moderate evidence that cannabis-based medicines (CBM) can contribute to a significant reduction in pain, especially the associated pain affect, and improvement in physical function and sleep quality in a proportion of patients with chronic pain. The analgesic effect appears to be largely independent of the cause of pain. In this context, CBM preferentially regulates stress-associated pain processing.

The Nocebo Effect: A Bias in Clinical Practice-An Ethical Approach

BACKGROUND

The nocebo effect is often disregarded in medical practice and is certainly much less known than the placebo effect, although, in reality, both can influence therapeutic decision making and the quality of life of patients. However, the nocebo effect raises a number of issues not only of a practical nature related to clinical activity but also ethical dilemmas related to the observance of the patient's autonomy, nonmaleficence, or informed consent and the information on which it is based.

AREAS OF UNCERTAINTY

The ethical dilemmas raised by the nocebo effect revolve around how informed consent can be achieved, the accuracy and volume of information that is transmitted to the patient, and how to report negative side effects of therapeutic treatment.

DATA SOURCES

In September 2023, a narrative analysis of the literature was conducted using a combination of keywords such as nocebo, placebo, ethics, therapeutic relationship from PubMed, Scopus, Google Scholar, and so on, as well as from official documents developed at an international level (World Health Organization), for a period of 10 years (2012-2021).

RESULTS

Analyzing the articles that remarked upon the significant impact of ethics in nocebo research or in the therapeutic relationship, we can state that the existence of several relevant issues of interest have been detected regarding the ethical use of nocebo and its impact in research or in clinics and thus the need for proper knowledge and management of the impact of nocebo effects. The ethical paradox of obtaining informed consent with the 2 goals, first, the need for complete information and second, the preservation of the autonomy of the patient, respectively, that of "primum non-nocere" and of avoiding unnecessary harm by revealing probable adverse effects is a point of interest for numerous studies. The potential for a nocebo effect is present when we inform patients about the risks and benefits of treatment, there being a clear link between the moral and ethical duty to inform patients and the need to avoid situations that increase the nocebo impact on how the disease or the adverse effects of the treatment are perceived. Adapting information about the side effects of medicines should focus on ensuring a balance between transparency and caution, especially in patients with a high potential for nocebo effect.

CONCLUSIONS

The nocebo effect had for a long time been unknown or denied, although it can interfere with the results of the treatment used. As the nocebo phenomenon becomes increasingly known in medical practice, the clinical and ethical implications are identified by medical staff, and nocebo's adverse responses are no longer ignored.

Pain, Conflicted Feelings About Work, and Sickness Absence: A Prospective Study of the Effects of Number of Pain Sites and Role Conflicts on Medically Certified Sickness Absence

We investigated associations between the number of pain sites (NPS) and role conflict with medically certified, pain-related sickness absence (SA) in employees of Norwegian enterprises (N = 5,654). Latent profile analyses identified exposure profiles based on 3 types of role conflict (work-role conflict, work-life conflict, and emotional dissonance). Multinomial logistic regressions estimated effects on absence (short-term absence of less than 56 days, long-term absence of more than 56 days) during 1 year after survey. Effects of the NPS on absence were compared across exposure profiles. Results suggested the NPS and all types of role conflict predicted absences separately. Mutually adjusted regressions revealed unique contributions of the NPS to the short-term and long-term absence (odds ratio [OR] 1.24, 95% confidence interval [CI] 1.18, 1.30 and OR 1.51, 95% CI 1.37, 1.66) and of work-role conflict to the short-term absence (OR 1.18, 95% CI 1.03, 1.35). Latent profile analyses identified 4 exposure profiles ("1 unconflicted," "2 dissonant, otherwise medium," "3 conflicted, medium dissonance," "4 conflicted and dissonant"). Profiles 3 and 4 exhibited elevated risk of SA, with the strongest baseline-adjusted effects for profile 4 (short-term absence OR 1.90, 95% CI 1.40, 2.57, long-term absence OR 1.95, 95% CI 1.15, 3.31). Effects of the NPS on short-term absence were stronger for profile 4 versus profile 1 (OR 1.38 vs 1.24, P < .001). Our findings suggest that addressing role conflicts may prevent pain-related absence, possibly also for individuals already experiencing pain. PERSPECTIVE: This article elucidates the connections between role conflicts associated with work roles, the NPS, and SA due to pain. This should help organizations prevent pain-related absences from work and improve working conditions for workers who remain occupationally active in spite of pain problems.

IUPHAR review: Navigating the role of preclinical models in pain research

Chronic pain is a complex and challenging medical condition that affects millions of people worldwide. Understanding the underlying mechanisms of chronic pain is a key goal of preclinical pain research so that more effective treatment strategies can be developed. In this review, we explore nociception, pain, and the multifaceted factors that lead to chronic pain by focusing on preclinical models. We provide a detailed look into inflammatory and neuropathic pain models and discuss the most used animal models for studying the mechanisms behind these conditions. Additionally, we emphasize the vital role of these preclinical models in developing new pain-relief drugs, focusing on biologics and the therapeutic potential of NMDA and cannabinoid receptor antagonists. We also discuss the challenges of TRPV1 modulation for pain treatment, the clinical failures of neurokinin (NK)- 1 receptor antagonists, and the partial success story of Ziconotide to provide valuable lessons for preclinical pain models. Finally, we highlight the overall success and limitations of current treatments for chronic pain while providing critical insights into the development of more effective therapies to alleviate the burden of chronic pain.

Placebo analgesia and nocebo hyperalgesia in patients with Alzheimer disease and healthy participants

ABSTRACT

The role of placebo analgesia and nocebo hyperalgesia in patients with Alzheimer disease (AD) is largely unknown, with only few studies in the area. Therefore, this study aims to investigate to which extent placebo analgesia and nocebo hyperalgesia effects are present in patients experiencing mild-to-moderate AD. Twenty-one patients with AD (test population) and 26 healthy participants (HP; design validation) were exposed to thermal pain stimulation on 3 test days: Lidocaine condition (open/hidden lidocaine administration), capsaicin condition (open/hidden capsaicin administration), and natural history (no treatment), in a randomized, within-subject design. Open lidocaine and open capsaicin were accompanied by verbal suggestions for pain relief and pain increase, respectively. Expected pain and actual pain intensity were measured on a numerical rating scale (0-10). Placebo and nocebo effects were calculated as pain differences in open-hidden lidocaine and capsaicin, respectively, controlled for no treatment. Healthy participants obtained a placebo effect ( P = 0.01) and a trend for a nocebo effect ( P = 0.07). Patients with AD did not obtain a placebo effect ( P = 0.44) nor a significant nocebo effect ( P = 0.86). Healthy participants expected lower and higher pain with open vs hidden lidocaine and capsaicin, respectively ( P < 0.001). The same expectation effects were seen in patients with AD (open vs hidden lidocaine, P = 0.008; open vs hidden capsaicin, P < 0.001). With a well-controlled experimental setting, this study suggests that patients with AD may not experience placebo analgesia effects. Nocebo hyperalgesia effects in patients with AD needs further research. These findings may have implications for the conduction of clinical trials and the treatment of patients with AD in clinical practice.

Cooperative Learning for Personalized Context-Aware Pain Assessment From Wearable Data

Despite the promising performance of automated pain assessment methods, current methods suffer from performance generalization due to the lack of relatively large, diverse, and annotated pain datasets. Further, the majority of current methods do not allow responsible interaction between the model and user, and do not take different internal and external factors into consideration during the model's design and development. This article aims to provide an efficient cooperative learning framework for the lack of annotated data while facilitating responsible user communication and taking individual differences into consideration during the development of pain assessment models. Our results using body and muscle movement data, collected from wearable devices, demonstrate that the proposed framework is effective in leveraging both the human and the machine to efficiently learn and predict pain.

The development of the Therapeutic Group Context Questionnaire: Reliability and validity measures based on telehealth Group-based Pain Management Programs

INTRODUCTION

In 2016, the Centers for Disease Control and Prevention analyzed the National Health Interview Survey data and found that the occurrence of chronic pain and high-impact chronic pain in the USA was 20.4% and 8%, respectively. Group-based Pain Management Programs have been viewed as significant treatments aiding patients with self-management of chronic pain. The onset of coronavirus disease 2019 (COVID-19) at the beginning of 2020, widely eliminated the in-person Group-based Pain Management Programs. The exploration of therapeutic contextual factors such as the therapeutic alliance and group dynamics in telehealth Group-based Pain Management Programs appears warranted for which reason the Therapeutic Group Context Questionnaire was developed.

METHODS

The therapeutic alliance and group dynamics items in the Therapeutic Group Context Questionnaire were developed from an extensive literature review and underwent examination of content validity, internal consistency, reliability, and validity through telehealth Group-based Pain Management Programs.

RESULTS

Content validity of the Therapeutic Group Context Questionnaire was established in five separate stages and the psychometrics of the Therapeutic Group Context Questionnaire was found to be very good with high internal consistency and reliability (r = 0.85-0.97) and the ability of the Therapeutic Group Context Questionnaire to differentiate between high and low scorers on the SF-36 emotional well-being measure.

DISCUSSION

The examination of therapeutic contextual factors via telehealth Group-based Pain Management Programs using the Therapeutic Group Context Questionnaire appears possible in view of the very good psychometric properties described above. Investigation of therapeutic contextual factors through the Therapeutic Group Context Questionnaire may provide greater insight into the role that these factors may have in telehealth programs and their impact on pain outcomes. Future investigation of the Therapeutic Group Context Questionnaire in non-telehealth Group-based Pain Management Programs, as well as, other disorders being addressed via telehealth appears warranted.

Placebo treatment affects brain systems related to affective and cognitive processes, but not nociceptive pain

Placebo analgesia is a replicable and well-studied phenomenon, yet it remains unclear to what degree it includes modulation of nociceptive processes. Some studies find effects consistent with nociceptive effects, but meta-analyses show that these effects are often small. We analyzed placebo analgesia in a large fMRI study (N = 392), including placebo effects on brain responses to noxious stimuli. Placebo treatment caused robust analgesia in both conditioned thermal and unconditioned mechanical pain. Placebo did not decrease fMRI activity in nociceptive pain regions, including the Neurologic Pain Signature (NPS) and pre-registered spinothalamic pathway regions, with strong support from Bayes Factor analyses. However, placebo treatment affected activity in pre-registered analyses of a second neuromarker, the Stimulus Intensity Independent Pain Signature (SIIPS), and several associated a priori brain regions related to motivation and value, in both thermal and mechanical pain. Individual differences in behavioral analgesia were correlated with neural changes in both thermal and mechanical pain. Our results indicate that processes related to affective and cognitive aspects of pain primarily drive placebo analgesia.

The Biology of Chronic Pain and Its Implications for Pain Neuroscience Education: State of the Art

Pain is an individualized experience for the person suffering from chronic pain. Significant strides have been made in the last few decades in understanding various biological changes that coincide with chronic pain. This state-of-the-art overview looks at the current evidence related to the biology of chronic pain and the implications these findings have on the delivery of pain neuroscience education (PNE). The paper summarizes the various (epi)genetic, neural, endocrine, and immune factors discovered and explored in the scientific literature concerning chronic pain. Each of these biological factors has various implications for the content and delivery of PNE. We discuss the future directions these biological factors have for the clinical implementation of PNE by linking the importance of behavior change, optimizing the learning environment, and using an individualized multimodal treatment approach with PNE. In addition, future directions for research of PNE based on these biological factors are provided with importance placed on individualized patient-centered care and how PNE can be used with traditional modes of care and growing trends with other care methods. PNE was originally and continues to be rooted in understanding chronic pain biology and how that understanding can improve patient care and outcomes.

The Biology of Placebo and Nocebo Effects on Experimental and Chronic Pain: State of the Art

(1) Background: In recent years, placebo and nocebo effects have been extensively documented in different medical conditions, including pain. The scientific literature has provided strong evidence of how the psychosocial context accompanying the treatment administration can influence the therapeutic outcome positively (placebo effects) or negatively (nocebo effects). (2) Methods: This state-of-the-art paper aims to provide an updated overview of placebo and nocebo effects on pain. (3) Results: The most common study designs, the psychological mechanisms, and neurobiological/genetic determinants of these phenomena are discussed, focusing on the differences between positive and negative context effects on pain in experimental settings on healthy volunteers and in clinical settings on chronic pain patients. Finally, the last section describes the implications for clinical and research practice to maximize the medical and scientific routine and correctly interpret the results of research studies on placebo and nocebo effects. (4) Conclusions: While studies on healthy participants seem consistent and provide a clear picture of how the brain reacts to the context, there are no unique results of the occurrence and magnitude of placebo and nocebo effects in chronic pain patients, mainly due to the heterogeneity of pain. This opens up the need for future studies on the topic.

Musculoskeletal practitioners' perceptions of contextual factors that may influence chronic low back pain outcomes: a modified Delphi study

BACKGROUND

Optimal shaping of contextual factors (CFs) during clinical encounters may be associated with analgesic responses in treatments for musculoskeletal pain. These CFs (i.e., the patient-practitioner relationship, patient's and practitioner's beliefs/characteristics, treatment characteristics, and environment) have not been widely evaluated by musculoskeletal practitioners. Understanding their views has the potential to improve treatment quality and effectiveness. Drawing on a panel of United Kingdom practitioners' expertise, this study aimed to investigate their perceptions of CFs during the management of patients presenting with chronic low back pain (LBP).

METHODS

A modified two-round online Delphi-consensus survey was conducted to measure the extent of panel agreement regarding the perceived acceptability and influence of five main types of CFs during clinical management of patients with chronic LBP. Qualified musculoskeletal practitioners in the United Kingdom providing regular treatment for patients with chronic LBP were invited to take part.

RESULTS

The successive Delphi rounds included 39 and 23 panellists with an average of 19.9 and 21.3 years of clinical experience respectively. The panel demonstrated a high degree of consensus regarding approaches to enhance the patient-practitioner relationship (18/19 statements); leverage their own characteristics/beliefs (10/11 statements); modify the patient's beliefs and consider patient's characteristics (21/25 statements) to influence patient outcomes during chronic LBP rehabilitation. There was a lower degree of consensus regarding the influence and use of approaches related to the treatment characteristics (6/12 statements) and treatment environment (3/7 statements), and these CFs were viewed as the least important. The patient-practitioner relationship was rated as the most important CF, although the panel were not entirely confident in managing a range of patients' cognitive and emotional needs.

CONCLUSION

This Delphi study provides initial insights regarding a panel of musculoskeletal practitioners' attitudes towards CFs during chronic LBP rehabilitation in the United Kingdom. All five CF domains were perceived as capable of influencing patient outcomes, with the patient-practitioner relationship being perceived as the most important CF during routine clinical practice. Musculoskeletal practitioners may require further training to enhance their proficiency and confidence in applying essential psychosocial skills to address the complex needs of patients with chronic LBP.

The effect of preconditioning on the modalities of pain management

OBJECTIVES

This study investigated the effect of positive preconditioning on the specific modality of verbal and touch interventions, in pain management.

METHODS

We compared pain ratings in 51 participants who underwent a cold pressor test twice (T1, T2). The results from the first test were used as a reference. For the second test, the participants were divided into 5 groups. Four groups received verbal or touch intervention during the test, with or without preconditioning. The fifth group was a control group. We compared dVAS (pain ratings at T1 minus T2) between groups to assess the effect of the interventions and the preconditioning. We also explored the within-group association between dVAS and pain-related traits.

RESULTS

We found a significant effect of preconditioning on dVAS. The post hoc test showed that the preconditioned verbal group reported higher dVAS than the non-preconditioned one. Participants' emotional awareness scores were negatively correlated with dVAS in the preconditioned touch group.

CONCLUSION

These data suggested that preconditioning enhances pain management, regardless of intervention modalities. However, the preconditioning effect for the touch modality was negatively associated with the participants' emotional awareness.

PRACTICE IMPLICATIONS

Communication must be adapted with caution, depending on the treatment and the patients' emotional status.

Complexity theory in the management of patients with musculoskeletal pain

Nonlinear systems are not susceptible to research with a reductionist approach. In this sense, the complexity theory provides an alternative approach to quantify the importance of contextual factors in patients with musculoskeletal pain. The use of positive (placebo) or negative (nocebo) contextual factors in the therapeutic setting could largely account for the non-specific component of treatment efficacy, directly affecting the quality of patients’ health-related outcomes (e.g., pain, disability, or satisfaction). In recent years, there has been a better understanding of the effects of contextual factors. However, the knowledge and awareness of them is limited and heterogeneous among physical therapists, reducing their translational value in the field of physiotherapy. The purpose of this essay is to describe the management of patients with musculoskeletal pain from the complexity theory perspective.

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

BACKGROUND

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

METHODS

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

RESULT

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

CONCLUSION

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

Impact of contextual factors on patient outcomes following conservative low back pain treatment: systematic review

BACKGROUND AND OBJECTIVE

Chronic low back pain is pervasive, societally impactful, and current treatments only provide moderate relief. Exploring whether therapeutic elements, either unrecognised or perceived as implicit within clinical encounters, are acknowledged and deliberately targeted may improve treatment efficacy. Contextual factors (specifically, patient's and practitioner's beliefs/characteristics; patient-practitioner relationships; the therapeutic setting/environment; and treatment characteristics) could be important, but there is limited evidence regarding their influence. This research aims to review the impact of interventions modifying contextual factors during conservative care on patient's pain and physical functioning.

DATABASES AND DATA TREATMENT

Four electronic databases (Medline, CINAHL, PsycINFO and AMED) were searched from 2009 until 15th February 2022, using tailored search strategies, and resulted in 3476 unique citations. After initial screening, 170 full-text records were potentially eligible and assessed against the inclusion-exclusion criteria. Thereafter, studies were assessed for methodological quality using a modified Downs and Black scale, data extracted, and synthesised using a narrative approach.

RESULTS

Twenty-one primary studies (N = 3075 participants), were included in this review. Eight studies reported significant improvements in pain intensity, and seven in physical functioning, in favour of the contextual factor intervention(s). Notable contextual factors included: addressing maladaptive illness beliefs; verbal suggestions to influence symptom change expectations; visual or physical cues to suggest pain-relieving treatment properties; and positive communication such as empathy to enhance the therapeutic alliance.

CONCLUSION

This review identified influential contextual factors which may augment conservative chronic low back pain care. The heterogeneity of interventions suggests modifying more than one contextual factor may be more impactful on patients' clinical outcomes, although these findings require judicious interpretation.

What is the nocebo effect and does it apply to dentistry? A narrative review

Background

Evidence for the nocebo effect, a phenomenon characterised by suboptimal treatment efficacy, worsening of symptoms, or the occurrence of adverse events caused by an individual’s negative treatment expectations, is growing across a multitude of medical fields. However, little attention has been paid to patients’ negative expectations and the nocebo effect within dentistry.

Aim

This review summarises essential evidence of the nocebo phenomenon especially in relation to pain and drug administration. Subsequently, an overview of the current evidence of the nocebo phenomenon in the dental field is presented.

Methods

A PubMed search was performed using keywords related to “nocebo,” “placebo,” “expectations,” and “dentistry.” In addition to the articles selected from the search, placebo/nocebo researchers and dental researchers added important references from their respective fields.

Results

Although research on the nocebo effect in dentistry is limited, available current evidence suggests that the factors, which is related to the nocebo effect are likely to play a role in dental practice.

Conclusion

Preliminary evidence from the review warrants further investigation into the nocebo effect in dentistry. Finally, based on the general knowledge of the nocebo effect, the review indicates fruitful arrays of research into the nocebo effect in dentistry.

Beating Pain with Psychedelics: Matter over Mind?

Basic pain research has shed light on key cellular and molecular mechanisms underlying nociceptive and phenomenological aspects of pain. Despite these advances, [[we still yearn for] the discovery of novel therapeutic strategies to address the unmet needs of about 70% of chronic neuropathic pain patients whose pain fails to respond to opioids as well as to other conventional analgesic agents. Importantly, a substantial body of clinical observations over the past decade cumulatively suggests that the psychedelic class of drugs may possess heuristic value for understanding and treating chronic pain conditions. The present review presents a theoretical framework for hitherto insufficiently understood neuroscience-based mechanisms of psychedelics' potential analgesic effects. To that end, searches of PubMed-indexed journals were performed using the following Medical Subject Headings' terms: pain, analgesia, inflammatory, brain connectivity, ketamine, psilocybin, functional imaging, and dendrites. Recursive sets of scientific and clinical evidence extracted from this literature review were summarized within the following key areas: (1) studies employing psychedelics for alleviation of physical and emotional pain; (2) potential neuro-restorative effects of psychedelics to remediate the impaired connectivity underlying the dissociation between pain-related conscious states/cognitions and the subcortical activity/function leading to the eventual chronicity through immediate and long-term effects on dentritic plasticity; (3) anti-neuroinflammatory and pro-immunomodulatory actions of psychedelics as the may pertain to the role of these factors in the pathogenesis of neuropathic pain; (4) safety, legal, and ethical consideration inherent in psychedelics' pharmacotherapy. In addition to direct beneficial effects in terms of reduction of pain and suffering, psychedelics' inclusion in the analgesic armamentarium will contribute to deeper and more sophisticated insights not only into pain syndromes but also into frequently comorbid psychiatric condition associated with emotional pain, e.g., depressive and anxiety disorders. Further inquiry is clearly warranted into the above areas that have potential to evolve into further elucidate the mechanisms of chronic pain and affective disorders, and lead to the development of innovative, safe, and more efficacious neurobiologically-based therapeutic approaches.

A social affective neuroscience lens on placebo analgesia

Pain is a fundamental experience that promotes survival. In humans, pain stands at the intersection of multiple health crises: chronic pain, the opioid epidemic, and health disparities. The study of placebo analgesia highlights how social, cognitive, and affective processes can directly shape pain, and identifies potential paths for mitigating these crises. This review examines recent progress in the study of placebo analgesia through affective science. It focuses on how placebo effects are shaped by expectations, affect, and the social context surrounding treatment, and discusses neurobiological mechanisms of placebo, highlighting unanswered questions and implications for health. Collaborations between clinicians and social and affective scientists can address outstanding questions and leverage placebo to reduce pain and improve human health.

Placebo response and effect in randomized clinical trials: meta-research with focus on contextual effects

BACKGROUND

Contextual effects (i.e., placebo response) refer to all health changes resulting from administering an apparently inactive treatment. In a randomized clinical trial (RCT), the overall treatment effect (i.e., the post-treatment effect in the intervention group) can be regarded as the true effect of the intervention plus the impact of contextual effects. This meta-research was conducted to examine the average proportion of the overall treatment effect attributable to contextual effects in RCTs across clinical conditions and treatments and explore whether it varies with trial contextual factors.

METHODS

Data was extracted from trials included in the main meta-analysis from the latest update of the Cochrane review on "Placebo interventions for all clinical conditions" (searched from 1966 to March 2008). Only RCTs reported in English having an experimental intervention group, a placebo comparator group, and a no-treatment control group were eligible.

RESULTS

In total, 186 trials (16,655 patients) were included. On average, 54% (0.54, 95%CI 0.46 to 0.64) of the overall treatment effect was attributable to contextual effects. The contextual effects were higher for trials with blinded outcome assessor and concealed allocation. The contextual effects appeared to increase proportional to the placebo effect, lower mean age, and proportion of females.

CONCLUSION

Approximately half of the overall treatment effect in RCTs seems attributable to contextual effects rather than to the specific effect of treatments. As the study did not include all important contextual factors (e.g., patient-provider interaction), the true proportion of contextual effects could differ from the study's results. However, contextual effects should be considered when assessing treatment effects in clinical practice.

TRIAL REGISTRATION

PROSPERO CRD42019130257 . Registered on April 19, 2019.

Understanding Contextual Factors Effects and Their Implications for Italian Physiotherapists: Findings from a National Cross-Sectional Study

An online cross-sectional survey was conducted using Google Docs software. The aim was to understand the management of contextual factors and to identify which are most relevant and which clinicians underestimate. A total of 1250 physiotherapists were chosen from the database of the Manual Therapists group mailing list (GTM-IFOMPT MO) from July to August 2020. A total of 699 responses were received that were considered valid (56%). Participants (40.83%) identified contextual factors (CFs) as "any element, even involuntary, with which the patient interacts during treatment". Physiotherapists individually chose the representation of CF with the "therapeutic relationship" (82.9%), followed by "therapeutic setting" (75.8%). This choice differed between participants belonging to different age groups. Participants favor communication strategies (76.93%). More than half (57.88%) pay attention to patient involvement during the course of care; and in response to the patients' doubts about the use of treatments with limited scientific efficacy, they suggest different medical treatments. The patient's previous clinical experience is not considered significant and does not influence the choice of treatment. Subsequently, however, the participants reported that they stimulate the patients' positive expectations of the success of the clinical outcome (45.27%). Knowledge of contextual factors in physiotherapy appears limited and very heterogeneous. Future research could increase the focus on professional development.

Direct and mediated effects of treatment context on low back pain outcome: a prospective cohort study

OBJECTIVES

Contextual components of treatment previously associated with patient outcomes include the environment, therapeutic relationship and expectancies. Questions remain about which components are most important, how they influence outcomes and comparative effects across treatment approaches. We aimed to identify significant and strong contextual predictors of patient outcomes, test for psychological mediators and compare effects across three treatment approaches.

DESIGN

Prospective cohort study with patient-reported and practitioner-reported questionnaire data (online or paper) collected at first consultation, 2 weeks and 3 months.

SETTING

Physiotherapy, osteopathy and acupuncture clinics throughout the UK.

PARTICIPANTS

166 practitioners (65 physiotherapists, 46 osteopaths, 55 acupuncturists) were recruited via their professional organisations. Practitioners recruited 960 adult patients seeking treatment for low back pain (LBP).

PRIMARY AND SECONDARY OUTCOMES

The primary outcome was back-related disability. Secondary outcomes were pain and well-being. Contextual components measured were: therapeutic alliance; patient satisfaction with appointment systems, access, facilities; patients' treatment beliefs including outcome expectancies; practitioners' attitudes to LBP and practitioners' patient-specific outcome expectancies. The hypothesised mediators measured were: patient self-efficacy for pain management; patient perceptions of LBP and psychosocial distress.

RESULTS

After controlling for baseline and potential confounders, statistically significant predictors of reduced back-related disability were: all three dimensions of stronger therapeutic alliance (goal, task and bond); higher patient satisfaction with appointment systems; reduced patient-perceived treatment credibility and increased practitioner-rated outcome expectancies. Therapeutic alliance over task (η_p²=0.10, 95% CI 0.07 to 0.14) and practitioner-rated outcome expectancies (η_p²=0.08, 95% CI 0.05 to 0.11) demonstrated the largest effect sizes. Patients' self-efficacy, LBP perceptions and psychosocial distress partially mediated these relationships. There were no interactions with treatment approach.

CONCLUSIONS

Enhancing contextual components in musculoskeletal healthcare could improve patient outcomes. Interventions should focus on helping practitioners and patients forge effective therapeutic alliances with strong affective bonds and agreement on treatment goals and how to achieve them.

The placebo phenomenon and the underlying mechanisms

The clinical role of the placebo effect is a topic of increasing interest for the scientific community. Focus is shifting from the inert role of placebos in randomized controlled trials (RCTs) to potential effects in clinical applications, since the phenomenon is thought to be inherent in routine clinical practice, affecting therapy success rates. Mediation of the mind-brain-body relationship involves both psychosocial and neurobiological factors, the interaction of which comprises the placebo mechanisms. Psychosocial factors include environmentally induced expectations, reward expectations, and even conditioned responses to certain stimuli. Expectations also depend on previous experience of the patient with a similar procedure and can affect future responses. Moreover, the supportive bedside behavior of the clinician and the positive framing of information provided to the patient have proven to be of great importance, setting the foundations for reconsideration of standardized practices. Neurobiological mechanisms mediate these effects through neurotransmitter and neuromodulator pathways. The best understood mechanisms are those regulating non-opioid- and opioid-mediated analgesic responses that implicate specific brain regions of pain control and activation of endogenous opioids. Other responses concern, among others, hormonal control, motor performance, and antidepressant responses. Although mechanisms underlying placebo responses are not as yet completely elucidated, there is substantial evidence suggesting that placebo effects are indicative of healthy functioning of intact brain structures and occur through actual functional changes, and are not simply subjective symptom reports. These effects can be utilized in treatment optimization while maintaining an ethical and respectful manner toward the patient and the standardized disclosure procedures.

A Meta-Analysis of Group-Based Pain Management Programs: Overall Effect on Quality of Life and Other Chronic Pain Outcome Measures, with an Exploration into Moderator Variables that Influence the Efficacy of Such Interventions

OBJECTIVES

Group-based pain management programs (GPMPs) have been found to significantly improve quality of life and other pain outcome measures in patients with chronic musculoskeletal pain. The aims of this meta-analysis were to reevaluate the overall effect of GPMPs on various pain outcomes for individuals experiencing chronic musculoskeletal conditions and to explore moderator variables that potentially contribute to the overall efficacy of GPMPs.

METHODS

Using the R package called metaphor and RevMan, we estimated the overall effectiveness of GPMPs on various pain outcome measures. The differential effectiveness of GPMPs was examined by conducting a mixed-effects meta-analytic model using various study-level characteristics. Moderator analyses included three content moderator variables and seven format moderator variables. Receiver operating characteristic curves investigated optimal points in some of the moderator variable analysis results.

RESULTS

Significant overall main effects of GPMPs were found on all the explored outcome measures in this study (P < 0.05). In moderator analyses, it was found that the structure of GPMPs, rather than the content, significantly improved outcomes (P < 0.05). Receiver operating characteristic curve analyses identified the optimal number of GPMP sessions and number of participants per group.

DISCUSSION AND CLINICAL RELEVANCE

GPMPs have a statistically significant overall effect on all explored pain outcome measures. The investigation into content and structural moderators suggests that certain GPMP design factors have a greater effect on pain outcomes than do content factors. Therefore, GPMP structural designs appear to be important in reducing pain and improving quality of life for patients with chronic pain and warrant further investigation.

What Physiotherapists Specialized in Orthopedic Manual Therapy Know About Nocebo-Related Effects and Contextual Factors: Findings From a National Survey

Objective

The aim of this study was to investigate the knowledge of orthopedic manual therapists (OMTs) regarding context factors (CFs) capable of triggering nocebo effects during the treatment and how this knowledge is related to their socio-demographic features.

Design

A cross-sectional online survey.

Setting

National.

Main Outcome Measures

A 20 items questionnaire composed by open-ended and closed single-choice questions was administered to explore: (a) socio-demographic variables (10 questions); (b) the relation between different CFs and nocebo-related effects (2 questions); and (c) the knowledge of participants about nocebo-related effects and how they managed them in the clinical practice (8 questions).

Participants

1288 OMTs were recruited from the database of the Master in Rehabilitation of Musculoskeletal Disorders (MRDM) of the University of Genova from March to May 2019. Inclusion criteria were: (a) to possess a valid email account; (b) to understand and use as a native language the Italian; (c) to be graduated as OMTs; and (d) to be employed as physiotherapists specialized-OMTs during the survey.

Results

791 responses were received (61.4%); 473 of them were male (59.8%), with an average age of 31.0 ± 7.1 years. OMTs defined nocebo-related effects as the psychosocial context effects around therapy and patient with specific biological bases (72.2%). OMTs know that their clinical practice is pervaded by nocebo-related effects (42.5%), triggered by CFs. Participants communicated nocebo-related effects balancing the positive features of the therapy with the negative ones (50.9%), during the decision of the therapeutic plan (42.7%). They reported associative learning as the main mechanism involved in nocebo-related effects (28.8%). OMTs taught and trained patient’s strategies to manage nocebo-related effects (39.6%) through an evaluation and correction of patient’s anxieties, doubts and expectations (37.7%). OMTs most frequently considered themselves to have a “medium” education about nocebo-related effects (48.2%) and that their management should be taught during bachelor (78.6%).

Conclusion

OMTs believed that nocebo-related effects were present in their clinical practice and that they can be triggered by CFs.

Can insights from placebo and nocebo mechanisms studies improve the randomized controlled trial?

Background and aims The randomized controlled trial (RCT) is currently facing several challenges, one of these being that the placebo response appears to be increasing in RCTs, thereby making it difficult to demonstrate an effect of potentially new treatments over placebo. This problem has primarily been approached by predicting the magnitude of the placebo response via stable factors, such as demographic variables, and/or by developing complex designs aimed at reducing the placebo response in the hope that it will improve the test of the active treatment. Yet, the success of this approach has so far been limited. Methods A new approach toward improving the RCT is put forward based on placebo and nocebo mechanism studies, i.e. studies that investigate the mechanisms underlying placebo analgesia and nocebo hyperalgesia. In a series of meta-analyses the magnitude of placebo and nocebo effects were determined. Experimental studies across nociplastic and neuropathic pain conditions and across pharmacological and acupuncture treatments investigated psychological and neurobiological mechanisms underlying these effects. The obtained results were used to make approximations of expectations to see if that could predict the placebo response in RCTs and function as a new way of tapping into the placebo component of treatment effects. Results The magnitude of placebo and nocebo effects is large and highly variable. Placebo effects exist across chronic pain conditions with varying degrees of known etiology as well as across pharmacological and non-pharmacological treatments. Patients' perception of the treatment, the verbal suggestions given for pain relief, and the patients' expectations toward pain relief contribute to the magnitude of the placebo effect and to pain relief following placebo interventions. Also, unintentional unblinding and patients' perception of a treatment markedly influence the treatment outcome. By making approximations of expectations toward treatment effects it was possible to predict the magnitude of the placebo response in RCTs. Conclusions and implications The new approach of tapping into or directly asking patients about their perception and expectations toward a treatment, along with the account of the natural history of pain, has the potential to improve the information that can be obtained from RCTs. Thus, by interfacing insights from placebo and nocebo mechanism studies, it may be possible to enhance the information that can be obtained from RCTs and to account for a large part of the variability in the placebo component of the overall treatment effect. This approach has the potential to improve the scientific evaluation of treatments, as well as to illustrate how the effect of treatments can be optimized in clinical practice, which is the crux of evidence-based medicine.

Context matters: the psychoneurobiological determinants of placebo, nocebo and context-related effects in physiotherapy

Background

Placebo and nocebo effects embody psychoneurobiological phenomena where behavioural, neurophysiological, perceptive and cognitive changes occur during the therapeutic encounter in the healthcare context. Placebo effects are produced by a positive healthcare context; while nocebo effects are consequences of negative healthcare context. Historically, placebo, nocebo and context-related effects were considered as confounding elements for clinicians and researchers. In the last two decades this attitude started to change, and the understanding of the value of these effects has increased. Despite the growing interest, the knowledge and the awareness of using the healthcare context to trigger placebo and nocebo effects is currently limited and heterogeneous among physiotherapists, reducing their translational value in the physiotherapy field.

Objectives

To introduce the placebo, nocebo and context-related effects by: (1) presenting their psychological models; (2) describing their neurophysiological mechanisms; (3) underlining their impact for the physiotherapy profession; and (4) tracing lines for future researches.

Conclusion

Several psychological mechanisms are involved in placebo, nocebo and context-related effects; including expectation, learning processes (classical conditioning and observational learning), reinforced expectations, mindset and personality traits. The neurophysiological mechanisms mainly include the endogenous opioid, the endocannabinoid and the dopaminergic systems. Neuroimaging studies have identified different brain regions involved such as the dorsolateral prefrontal cortex, the rostral anterior cingulate cortex, the periaqueductal gray and the dorsal horn of spine. From a clinical perspective, the manipulation of the healthcare context with the best evidence-based therapy represents an opportunity to trigger placebo effects and to avoid nocebo effects respecting the ethical code of conduct. From a managerial perspective, stakeholders, organizations and governments should encourage the assessment of the healthcare context aimed to improve the quality of physiotherapy services. From an educational perspective, placebo and nocebo effects are professional topics that should be integrated in the university program of health and medical professions. From a research perspective, the control of placebo, nocebo and context-related effects offers to the scientific community the chance to better measure the impact of physiotherapy on different outcomes and in different conditions through primary studies.

Matching actual treatment with patient administration-route-preference improves analgesic response among acute low back pain patients-a randomized prospective trial

Background

Accommodating a patient’s treatment preference has been reported to promote greater responsiveness and better clinical outcomes. The effect of administration route preference (ARP) on the individual analgesic response has not been extensively examined to date. This study aimed to investigate whether ARP-matched treatment, i.e., individualized intramuscular (IM) or oral (PO) analgesic administration according to patient choice, would increase the analgesic effect.

Methods

In this prospective randomized study, we collected 38 patients with acute low back pain (aLBP) presenting at the emergency room of the Galilee Medical Center (Naharia, Israel) and asked them to report their ARP for analgesics. Regardless of their reported preference, they received either PO or IM diclofenac according to the treating physician’s preference. Pain intensity was self-reported using the numeric pain score (NPS) before and during the first hour after drug administration.

Results

Both groups receiving PO or IM administration reported similar initial pain on admission, (NPS 8.63 ± 1.5 and 8.74 ± 1.6, respectively) and the same magnitude of pain reduction. However, patients who received the drug in their desired route (oral or injection) had a significantly greater reduction in pain levels (4.05 ± 2.8) as compared with patients who received the undesired route (2.08 ± 1.8), p < 0.05.

Conclusions

These findings support the hypothesis that individualized ARP-matched treatment in aLBP improves therapeutic outcomes, although further studies with larger cohorts are needed.

Failure of Placebo Analgesia Model in Rats with Inflammatory Pain

With the shifting role of placebos, there is a need to develop animal models of placebo analgesia and elucidate the mechanisms underlying the effect. In the present study, male Sprague-Dawley rats with chronic inflammatory pain caused by complete Freund's adjuvant (CFA) underwent a series of conditioning procedures, in which morphine was associated with different cues, but they failed to induce placebo analgesia. Then, conditioning with the conditioned place preference apparatus successfully induced analgesic expectancy and placebo analgesia in naïve rats but only induced analgesic expectancy and no analgesic effect in CFA rats. Subsequently, we found enhanced c-fos expression in the nucleus accumbens and reduced expression in the anterior cingulate cortex in naïve rats while c-fos expression in the anterior cingulate cortex in CFA rats was not altered. In summary, the behavioral conditioning model demonstrated the difficulty of establishing a placebo analgesia model in rats with a pathological condition.

The "virtual lesion" approach to transcranial magnetic stimulation: studying the brain-behavioral relationships in experimental pain

Transcranial magnetic stimulation (TMS) can be used to create a temporary “virtual lesion” (VL) of a target cortical area, disrupting its function and associated behavior. Transcranial magnetic stimulation can therefore test the functional role of specific brain areas. This scoping review aims at investigating the current literature of the “online” TMS-evoked VL approach to studying brain–behavioral relationships during experimental pain in healthy subjects. Ovid-Medline, Embase, and Web of Science electronic databases were searched. Included studies tested different TMS-based VLs of various pain brain areas during continuous experimental pain or when time-locked to a noxious stimulus. Outcome measures assessed different pain measurements. Initial screening resulted in a total of 403 studies, of which 17 studies were included in the review. The VLs were directed to the prefrontal, primary and secondary somatosensory, primary motor, and parietal cortices through single/double/triple/sequence of five-TMS pulses or through repeated TMS during mechanical, electrical contact, radiant heat, or capsaicin-evoked noxious stimulation. Despite a wide variability among the VL protocols, outcome measures, and study designs, a behavioral VL effect (decrease or increase in pain responses) was achieved in the majority of the studies. However, such findings on the relationships between the modified brain activity and the manifested pain characteristics were often mixed. To conclude, TMS–elicited VLs during experimental pain empower our understanding of brain–behavior relationships at specific time points during pain processing. The mixed findings of these relationships call for an obligatory standard of all pain-related TMS protocols for clearly determining the magnitude and direction of TMS-induced behavioral effects.

The Knowledge of Contextual Factors as Triggers of Placebo and Nocebo Effects in Patients With Musculoskeletal Pain: Findings From a National Survey

Backgrounds: Contextual factors (CFs) have been recently proposed as triggers of placebo and nocebo effects in musculoskeletal pain. CFs encompass the features of the clinician (e.g. uniform), patient (e.g. expectations), patient-clinician relationship (e.g. verbal communication), treatment (e.g. overt therapy), and healthcare setting (e.g. design). To date, the researchers' understanding of Italian patients' knowledge about the role of CFs in musculoskeletal pain is lacking. Objectives: The aim of this study was to investigate attitudes and beliefs of Italian patients with musculoskeletal pain about the use of CFs in clinical practice. Methods: A national sample of Italian patients with musculoskeletal pain was recruited from 12 outpatient private clinics in Italy. An invitation to participate in an online survey was sent to patients: a) exhibiting musculoskeletal pain; b) aged 18-75; c) with a valid e-mail account; and d) understanding Italian language. Survey Monkey software was used to deliver the survey. The questionnaire was self-reported and included 17 questions and 2 clinical vignettes on the patients' behavior, beliefs, and attitudes towards the adoption of CFs in clinical practice. Descriptive statistics and frequencies described the actual number of respondents to each question. Results: One thousand one hundred twelve patients participated in the survey. Five hundred seventy-four participants were female (52%). The average age of patients was 41.7 ± 15.2 years. Patients defined CFs as an intervention with an unspecific effect (64.3%), but they believed in their clinical effectiveness. They identified several therapeutic effects of CFs for different health problems. Their use was considered ethically acceptable when it exerts beneficial psychological effects (60.4%), but it was banned if considered deceptive (51.1%). During clinical practice, patients wanted to be informed about the use of CFs (46.0%) that are accepted as an addition to other interventions to optimize clinical responses (39.3%). Moreover, patients explained the power of CFs through body-mind connections (37.1%). Conclusion: Patients with musculoskeletal pain had positive attitudes towards the use and effectiveness of CFs when associated with evidence-based therapy. They mostly perceived the adoption of CFs in clinical practice as ethical.

Era of biosimilars in rheumatology: reshaping the healthcare environment

Compared with the original approved biological drug on which it is based, a biosimilar has highly similar physicochemical characteristics and biological activity, as well as equivalent efficacy and no clinically meaningful differences in safety and immunogenicity. Before they are approved, biosimilars must undergo a rigorous development process using state-of-the-art technologies to establish biosimilarity to the reference biological product. After approval, biosimilars must comply with good pharmacological practices for biological drugs. Several biosimilar disease-modifying antirheumatic drugs (bsDMARDs) based on the tumour necrosis factor inhibitors adalimumab, etanercept and infliximab have been approved for use in patients with rheumatic diseases. Substantial cost savings can be made if biological-naive patients begin treatment with bsDMARDs, and patients receiving original biological DMARDs (bDMARDs) are switched to bsDMARDs. Despite the consistently similar efficacy, safety and immunogenicity of bsDMARDs relative to their respective original bDMARDs, switching from a reference bDMARD to a bsDMARD can result in nocebo responses, such as subjective increase of disease activity and pain-related adverse events. This may have a negative impact on adherence to bsDMARDs in clinical trials and clinical practice. To ensure optimal and rational integration of bsDMARDs into rheumatology practice and realise the full cost-saving efficacy of these drugs, rheumatologists must be aware that careful communication of the cost-saving efficacy and safety of bsDMARDs to their patients is the key to a successful long-term switch to bsDMARD therapy.

The impact of contextual factors on nursing outcomes and the role of placebo/nocebo effects: a discussion paper

INTRODUCTION

Placebo and nocebo effects represent one of the most fascinating topics in the health care field.

OBJECTIVES

the aims of this discussion paper were (1) to briefly introduce the placebo and nocebo effects, (2) to elucidate the contextual factors able to trigger placebo and nocebo effects in the nursing field, and (3) to debate the impact of contextual factors on nursing education, practice, organisation, and research.

METHODS

a narrative review was conducted based on the available evidence.

RESULTS

Placebo responses (from Latin "I shall please") are a beneficial outcome(s) triggered by a positive context. The opposite are the nocebo effects (from Latin "I shall harm"), which indicates an undesirable outcome(s) caused by a negative context. Both are complex and distinct psychoneurobiological phenomena in which behavioural and neurophysiological changes arise subsequent to an interaction between the patient and the health care context.

CONCLUSION

Placebo and nocebo concepts have been recently introduced in the nursing discipline, generating a wide debate on ethical issues; however, the impact on nursing education, clinical practice, nursing administration, and research regarding contextual factors triggering nocebo and placebo effects has not been debated to date.

Human resource primacy, dispositional optimism, and chest pain: A prospective, cross-lagged study of work, personality, and health

Chest pain (CP) is common, frightening, and often medically unexplained. Occupational psychological factors are associated with somatic pain. Personality may influence both perceived working conditions and somatic health, thereby confounding associations of work with health. Despite this, very few studies have investigated the interplay between work factors, personality and pain. The current study assessed relationships of a relatively novel work factor, human resource primacy (HRP), and a personality factor known to be relevant to health, dispositional optimism (Opt), with CP across two years (N = 6714). A series of structural equation models (SEMs) were fitted, modeling "substantive" and "confounded" relationships of psychological factors with CP. A "common latent factor" (CLF) was included to account for bias by unmeasured factors that may have influenced all variables (e.g. reporting bias) and the role of optimism as a possible confounder of the relationship between HRP and CP was investigated specifically. Independent effects of HRP and Opt on CP were observed. No effects of HRP/CP on Opt were observed. Opt appeared to confound the relationship between HRP and CP to some extent. However, best fit was observed for a "reciprocal" model with independent lagged effects from HRP/Opt to CP as well as from CP/Opt to HRP. Thus, results suggested a mutual causal dynamic between HRP and CP along with an influence of Opt on both HRP and CP-implying that working conditions influence the experience of chest pain while the chest pain also influences the experience of working conditions. Optimistic dispositions may influence the experience of both work and pain, but not to an extent that fully explains their relationship. Hence, the notion that associations of HRP with CP are mere artifacts of optimistic/pessimistic reporting was not supported. More likely, complex reciprocal relationships exist between these factors, in which mutual reinforcements occur and both vicious and virtuous cycles may result.

Contextual factors triggering placebo and nocebo effects in nursing practice: Findings from a national cross-sectional study

AIMS AND OBJECTIVES

To describe contextual factors (CFs) used by nurses to increase placebo and to prevent nocebo effects.

BACKGROUND

Placebo effects have been studied in the nursing discipline, but nocebo effects still remain unexplored. Recently, a set of CFs functioning as triggers of placebo/nocebo effects has been described; however, its use in daily care has never been documented to date.

DESIGN

A national cross-sectional survey, according to the Checklist for Reporting Results of Internet E-Surveys guidelines and STrengthening the Reporting of OBservational Studies in Epidemiology (STROBE), was performed in 2016.

METHODS

A wide sample of Italian nurses belonging to four national associations was involved. A questionnaire based on CFs literature was developed and administered through the SurveyMonkey Software^® exploring: (a) CFs definition, (b) beliefs, (c) case-by-case frequency of use, (d) circumstances of application, (e) clinical conditions where participants perceived their potential beneficial effects, (f) ethical implications and (g) communication issues with the patient.

RESULTS

Out of 1,411 eligible nurses, 455 answered (32.2%) and 425 questionnaires (30.1%) were valid for the analysis. A total of 211 nurses (49.6%) defined the CFs as an intervention with a possible aspecific effect; participants believed in the CFs (2.91; 95%CI 2.88-2.94), using them >2 times/month, mainly in addition to a nursing intervention to optimise clinical outcomes (n = 79; 18.6%). Psychological and physiological therapeutic effects have been perceived mainly in chronic pain (n = 259; 60.9%) and insomnia (n = 243; 57.2%). According to participants, CFs have been reported as ethically acceptable when exerting beneficial psychological effects (n = 148; 34.8%); however, 103 (24.2%) of nurses did not communicate to the patient when CFs were used.

CONCLUSIONS

Nurses are aware of CFs as elements to increase the placebo and prevent the nocebo effects in concomitance with evidence-based nursing interventions.

RELEVANCE TO CLINICAL PRACTICE

The CFs valued by nurses and experienced as effective are mainly based upon the internal quality of the nurse and the quality of the relationship between the nurse and the patient. These qualities require a large personal investment; therefore, nurses should be supported in developing these qualities since their nursing graduation.

Psychobiological Mechanisms of Placebo and Nocebo Effects: Pathways to Improve Treatments and Reduce Side Effects

Placebo effects constitute a major part of treatment success in medical interventions. The nocebo effect also has a major impact, as it accounts for a significant proportion of the reported side effects for many treatments. Historically, clinical trials have aimed to reduce placebo effects; however, currently, there is interest in optimizing placebo effects to improve existing treatments and in examining ways to minimize nocebo effects to improve clinical outcome. To achieve these aims, a better understanding of the psychological and neurobiological mechanisms of the placebo and nocebo response is required. This review discusses the impact of the placebo and nocebo response in health care. We also examine the mechanisms involved in the placebo and nocebo effects, including the central mechanism of expectations. Finally, we examine ways to enhance placebo effects and reduce the impact of the nocebo response in clinical practice and suggest areas for future research.

A Qualitative Systematic Review of Effects of Provider Characteristics and Nonverbal Behavior on Pain, and Placebo and Nocebo Effects

Background: Previous research has indicated that the sex, status, and nonverbal behaviors of experimenters or clinicians can contribute to reported pain, and placebo and nocebo effects in patients or research participants. However, no systematic review has been published. Objective: The aim of this study was to investigate the effects of experimenter/clinician characteristics and nonverbal behavior on pain, placebo, and nocebo effects. Methods: Using EmBase, Web of Knowledge, and PubMed databases, several literature searches were conducted to find studies that investigated the effects of the experimenter's/clinician's sex, status, and nonverbal behaviors on pain, placebo, and nocebo effects. Results: Thirty-four studies were included, 20 on the effects of characteristics of the experimenter/clinician, 11 on the role of nonverbal behaviors, and 3 on the effects of both nonverbal behaviors and characteristics of experimenters/clinicians on pain and placebo/nocebo effects. There was a tendency for experimenters/clinicians to induce lower pain report in participants of the opposite sex. Furthermore, higher confidence, competence, and professionalism of experimenters/clinicians resulted in lower pain report and higher placebo effects, whereas lower status of experimenters/clinicians such as lower confidence, competence, and professionalism generated higher reported pain and lower placebo effects. Positive nonverbal behaviors (e.g., smiling, strong tone of voice, more eye contact, more leaning toward the patient/participant, and more body gestures) contributed to lower reported pain and higher placebo effects, whereas negative nonverbal behaviors (i.e., no smile, monotonous tone of voice, no eye contact, leaning backward from the participant/patient, and no body gestures) contributed to higher reported pain and nocebo effects. Conclusion: Characteristics and nonverbal behaviors of experimenters/clinicians contribute to the elicitation and modulation of pain, placebo, and nocebo effects.

Physical therapists' perspectives on using contextual factors in clinical practice: Findings from an Italian national survey

Background

Contextual factors (CFs) represent a potential therapeutic tool to boost physiotherapy outcomes, triggering placebo effects. Nevertheless, no evidence about the use of CFs among physical therapists is currently available.

Objective

To investigate the use of CFs and the opinion of Italian physical therapists specialized in Orthopaedic Manual Therapy (OMTs) on their therapeutic benefits.

Design

An exploratory cross-sectional online survey.

Methods

A 17-item questionnaire and 2 clinical vignettes assessed the perspective of OMTs on the adoption of CFs in daily clinical practice. The target population was composed of 906 OMTs. An online survey was performed in 2016 using SurveyMonkey Software. Data were analyzed by descriptive and inferential statistics.

Results

A total of 558 volunteers (61.6% of the target OMT population) participated in the study. Half of the participants (52.0%) claimed to use CFs frequently in their practice. More of 50% of OMTs valued the therapeutic significance of CFs for different health problems as determined by a combined psychological and physiological effect. OMTs considered the use of CFs ethically acceptable when they exert beneficial therapeutic effects and their effectiveness has emerged in previous clinical experiences (30.6%). They disagreed on the adoption of CFs when they are deceptive (14.1%). Moreover, OMTs did not communicate the adoption of CFs to patients (38.2%), and CFs were usually used in addition to other interventions to optimize clinical responses (19.9%). Psychological mechanisms, patient’s expectation and conditioning were believed to be the main components behind CFs (7.9%).

Limitations

Considering that the data collected were self-reported and retrospective, recall and response biases may limit the internal and external validity of the findings.

Conclusions

OMTs used CFs in their clinical practice and believed in their therapeutic effect. The knowledge of CFs, placebo and nocebo mechanisms and their clinical effects should be included in physical therapists’ university studies.

Sickness behavior is not all about the immune response: Possible roles of expectations and prediction errors in the worry of being sick

BACKGROUND

People react very differently when sick, and there are only poor correlations between the intensity of the immune response and sickness behavior. Yet, alternative predictors of the individual differences in sickness are under-investigated. Based on the predictive coding model of placebo responses, where health outcomes are function of bottom-up sensory information and top-down expectancies, we hypothesized that individual differences in behavioral changes during sickness could be explained by individual top-down expectancies and prediction errors.

METHODS

Twenty-two healthy participants were made sick by intravenously administering lipopolysaccharide (2 ng/kg body weight). Their expectations of becoming sick were assessed before the injection.

RESULTS

Participants having lower expectations of becoming sick before the injection reacted with more emotional distress (i.e., more negative affect and lower emotional arousal) than those with high expectations of becoming sick, despite having similar overall sickness behavior (i.e., a combined factor including fatigue, pain, nausea and social withdrawal). In keeping with a predictive coding model, the "prediction error signal", i.e., the discrepancy between the immune signal and sickness expectancy, predicted emotional distress (reduction in emotional arousal in particular).

CONCLUSION

The current findings suggest that the emotional component of sickness behavior is, at least partly, shaped by top-down expectations. Helping patients having a realistic expectation of symptoms during treatment of an illness may thus reduce aggravated emotional responses, and ultimately improve patients' quality of life and treatment compliance. REGISTRATION: "Endotoxin-induced Inflammatory and Behavioral Responses and Predictors of Individual Differences", https://clinicaltrials.gov/ct2/show/NCT02529592, registration number: NCT02529592.

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.

Thoracic manual therapy is not more effective than placebo thoracic manual therapy in patients with shoulder dysfunctions: A systematic review with meta-analysis

BACKGROUND

Manual treatments targeting different regions (shoulder, cervical spine, thoracic spine, ribs) have been studied to deal with patients complaining of shoulder pain. Thoracic manual treatments seem able to produce beneficial effects on this group of patients. However, it is not clear whether the patient improvement is a consequence of thoracic manual therapy or a placebo effect.

OBJECTIVES

To compare the efficacy of thoracic manual therapy and placebo thoracic manual treatment for patients with shoulder dysfunction.

METHODS

Electronic databases (MEDLINE, CENTRAL, PEDro, CINAHL, WoS, EMBASE, ERIC) were searched through November 2016. Randomized Controlled Trials assessing pain, mobility and function were selected. The Cochrane bias estimation tool was applied. Outcome results were either extracted or computed from raw data. Meta-analysis was performed for outcomes with low heterogeneity.

RESULTS

Four studies were included in the review. The methodology of the included studies was generally good except for one study that was rated as high risk of bias. Meta-analysis showed no significant effect for "pain at present" (SMD -0.02; 95% CI: -0.35, 0.32) and "pain during movement" (SMD -0.12; 95% CI: -0.45, 0.21).

CONCLUSION

There is very low to low quality of evidence that a single session of thoracic manual therapy is not more effective than a single session of placebo thoracic manual therapy in patients with shoulder dysfunction at immediate post-treatment.

Clinical relevance of contextual factors as triggers of placebo and nocebo effects in musculoskeletal pain

Placebo and nocebo effects are embodied psycho-neurobiological responses capable of modulating pain and producing changes at different neurobiological, body at perceptual and cognitive levels. These modifications are triggered by different contextual factors (CFs) presented in the therapeutic encounter between patient and healthcare providers, such as healing rituals and signs. The CFs directly impact on the quality of the therapeutic outcome: a positive context, that is a context characterized by the presence of positive CFs, can reduce pain by producing placebo effects, while a negative context, characterized by the presence of negative CFs, can aggravate pain by creating nocebo effects. Despite the increasing interest about this topic; the detailed study of CFs as triggers of placebo and nocebo effects is still lacked in the management of musculoskeletal pain.

Increasing evidence suggest a relevant role of CFs in musculoskeletal pain management. CFs are a complex sets of internal, external or relational elements encompassing: patient’s expectation, history, baseline characteristics; clinician’s behavior, belief, verbal suggestions and therapeutic touch; positive therapeutic encounter, patient-centered approach and social learning; overt therapy, posology of intervention, modality of treatment administration; marketing features of treatment and health care setting. Different explanatory models such as classical conditioning and expectancy can explain how CFs trigger placebo and nocebo effects. CFs act through specific neural networks and neurotransmitters that were described as mediators of placebo and nocebo effects.

Available findings suggest a relevant clinical role and impact of CFs. They should be integrated in the clinical reasoning to increase the number of treatment solutions, boosts their efficacy and improve the quality of the decision-making. From a clinical perspective, the mindful manipulation of CFs represents a useful opportunity to enrich a well-established therapy in therapeutic setting within the ethical border. From a translational perspective, there is a strong need of research studies on CFs close to routine and real-world clinical practice in order to underline the uncertainty of therapy action and help clinicians to implement knowledge in daily practice.

Enhancement of Meditation Analgesia by Opioid Antagonist in Experienced Meditators

OBJECTIVE

Studies have consistently shown that long-term meditation practice is associated with reduced pain, but the neural mechanisms by which long-term meditation practice reduces pain remain unclear. This study tested endogenous opioid involvement in meditation analgesia associated with long-term meditation practice.

METHODS

Electrical pain was induced with randomized, double-blind, cross-over administration of the opioid antagonist naloxone (0.15-mg/kg bolus dose, then 0.2-mg/kg per hour infusion dose) with 32 healthy, experienced meditation practitioners and a standardized open monitoring meditation.

RESULTS

Under saline, pain ratings were significantly lower during meditation (pain intensity: 6.41 ± 1.32; pain unpleasantness: 3.98 ± 2.17) than at baseline (pain intensity: 6.86 ±1.04, t(31) = 2.476, p = .019, Cohen's d = 0.46; pain unpleasantness: 4.96 ±1.75, t(31) = 3.746, p = .001, Cohen's d = 0.68), confirming the presence of meditation analgesia. Comparing saline and naloxone revealed significantly lower pain intensity (t(31) = 3.12, p = .004, d = 0.56), and pain unpleasantness (t(31) = 3.47, p = .002, d = 0.62), during meditation under naloxone (pain intensity: 5.53 ± 1.54; pain unpleasantness: 2.95 ± 1.88) than under saline (pain intensity: 6.41 ± 1.32; pain unpleasantness: 3.98 ± 2.17). Naloxone not only failed to eliminate meditation analgesia but also made meditation analgesia stronger.

CONCLUSIONS

Long-term meditation practice does not rely on endogenous opioids to reduce pain. Naloxone's blockade of opioid receptors enhanced meditation analgesia; pain ratings during meditation were significantly lower under naloxone than under saline. Possible biological mechanisms by which naloxone-induced opioid receptor blockade enhances meditation analgesia are discussed.