Effect of a nausea expectancy manipulation on chemotherapy-induced nausea: a university of Rochester cancer center community clinical oncology program study

Adverse events of active and placebo groups in SARS-CoV-2 vaccine randomized trials: A systematic review

Background

For safety assessment in clinical trials, adverse events (AEs) are reported for the drug under evaluation and compared with AEs in the placebo group. Little is known about the nature of the AEs associated with clinical trials of SARS-CoV-2 vaccines and the extent to which these can be traced to nocebo effects, where negative treatment-related expectations favor their occurrence.

Methods

In our systematic review, we compared the rates of solicited AEs in the active and placebo groups of SARS-CoV-2 vaccines approved by the Western pharmaceutical regulatory agencies.We implemented a search strategy to identify trial-III studies of SARS-CoV-2 vaccines through the PubMed database. We adopted the PRISMA Statement to perform the study selection and the data collection and identified three trial: two mRNA-based (37590 participants) and one adenovirus type (6736 participants).

Findings

Relative risks showed that the occurrence of AEs reported in the vaccine groups was higher compared with the placebo groups. The most frequently AEs in both groups were fatigue, headache, local pain, as injection site reactions, and myalgia. In particular, for first doses in placebo recipients, fatigue was reported in 29% and 27% in BNT162b2 and mRNA-1273 groups, respectively, and in 21% of Ad26.COV2.S participants. Headache was reported in 27% in both mRNA groups and in 24% of Ad26.COV2.S recipients. Myalgia was reported in 10% and 14% in mRNA groups (BNT162b2 and mRNA-1273, respectively) and in 13% of Ad26.COV2.S participants. Local pain was reported in 12% and 17% in mRNA groups (BNT162b2 and mRNA-1273, respectively), and in 17% of Ad26.COV2.S recipients. These AEs are more common in the younger population and in the first dose of placebo recipients of the mRNA vaccines.

Interpretation

Our results are in agreement with the expectancy theory of nocebo effects and suggest that the AEs associated with COVID-19 vaccines may be related to the nocebo effect.

Funding

Fondazione CRT - Cassa di Risparmio di Torino, IT (grant number 66346, "GAIA-MENTE" 2019).

Psychological predictors of chemotherapy-induced nausea in women with breast cancer: Expectancies and perceived susceptibility

Objective

Chemotherapy‐induced nausea is challenging to predict and treat. Research indicates that pretreatment psychological variables including patients' perceptions of their susceptibility to nausea, expectancies of treatment‐related nausea and nausea history (i.e., motion sickness, morning sickness and baseline levels of nausea) may aid in predicting nausea severity during chemotherapy. However, this research is dated and limited in quantity. We investigated whether psychological variables could improve prediction of nausea severity to inform interventions targeting chemotherapy‐induced nausea.

Methods

In this secondary analysis, a subgroup of women receiving chemotherapy (for the first time) for breast cancer completed pretreatment measures: perceived nausea susceptibility, nausea expectancies, nausea history and baseline nausea. They rated subsequent nausea severity across 4‐days, during treatment and posttreatment in a self‐report diary. Structural Equation Modelling was used to explore associations.

Results

Across the women (N = 481), perceived nausea susceptibility predicted subsequent nausea severity (β = 0.16), but nausea expectancies did not (β = 0.05). Nausea history variables demonstrated small‐moderate associations with perceived susceptibility (β = 0.21–0.32) and negligible‐small associations with nausea expectancies (β = 0.07–0.14).

Conclusion

Perceived nausea susceptibility appears to capture patients' nausea history, to a degree, and is related to nausea severity during treatment. This is an important variable to include in pretreatment prediction of patients at risk of severe nausea.

Bioengineering Technologies for Cardiac Regenerative Medicine

Cardiac regenerative medicine faces big challenges such as a lack of adult cardiac stem cells, low turnover of mature cardiomyocytes, and difficulty in therapeutic delivery to the injured heart. The interaction of bioengineering and cardiac regenerative medicine offers innovative solutions to this field. For example, cell reprogramming technology has been applied by both direct and indirect routes to generate patient-specific cardiomyocytes. Various viral and non-viral vectors have been utilized for gene editing to intervene gene expression patterns during the cardiac remodeling process. Cell-derived protein factors, exosomes, and miRNAs have been isolated and delivered through engineered particles to overcome many innate limitations of live cell therapy. Protein decoration, antibody modification, and platelet membranes have been used for targeting and precision medicine. Cardiac patches have been used for transferring therapeutics with better retention and integration. Other technologies such as 3D printing and 3D culture have been used to create replaceable cardiac tissue. In this review, we discuss recent advancements in bioengineering and biotechnologies for cardiac regenerative medicine.

Structural and Functional Characterization of Allatostatin Receptor Type-C of Thaumetopoea pityocampa, a Potential Target for Next-Generation Pest Control Agents

Insect neuropeptide receptors, including allatostatin receptor type C (AstR-C), a G protein-coupled receptor, are among the potential targets for designing next-generation pesticides that despite their importance in offering a new mode-of-action have been overlooked. Focusing on AstR-C of Thaumetopoea pityocampa, a common pest in Mediterranean countries, by employing resonance energy transfer-based methods, we showed Gαi/o coupling and β-arrestin recruitment of the receptor at sub-nanomolar and nanomolar ranges of the endogenous ligand, AST-C, respectively. Molecular docking and molecular dynamics simulation studies revealed the importance of extracellular loop 2 in AstRC/AST-C interaction, and a combination of in silico and in vitro approaches showed the substantial role of Q271^6.55 in G protein-dependent activation of AstR-C possibly via contributing to the flexibility of the receptor's structure. The functional and structural insights obtained on T. pit AstR-C positively assist future efforts in developing environmentally friendly pest control agents that are needed urgently.

A systematic review of factors associated with side-effect expectations from medical interventions

BACKGROUND

Fear of side-effects can result in non-adherence to medical interventions, such as medication and chemotherapy. Side-effect expectations have been identified as strong predictors of later perception of side-effects. However, research investigating predictors of side-effect expectations is disparate.

OBJECTIVE

To identify factors associated with side-effect expectations.

SEARCH STRATEGY

We systematically searched Embase, Ovid MEDLINE, Global Health, PsycARTICLES, PsycINFO, Web of Science and Scopus.

INCLUSION CRITERIA

Studies were included if they investigated associations between any predictive factor and expectations of side-effects from any medical intervention.

DATA EXTRACTION AND SYNTHESIS

We extracted information about participant characteristics, medication, rates of side-effects expected and predictors of side-effect expectations. Data were narratively synthesized.

MAIN RESULTS

We identified sixty-four citations, reporting on seventy-two studies. Predictors fell into five categories: personal characteristics, clinical characteristics, psychological traits and state, presentation format of information, and information sources used. Using verbal risk descriptors (eg 'common') compared to numerical descriptors (eg percentages), having lower quality of life or well-being, and currently experiencing symptoms were associated with increased side-effect expectations.

DISCUSSION AND CONCLUSIONS

Decreasing unrealistic side-effect expectations may lead to decreased experience of side-effects and increased adherence to medical interventions. Widespread communications about medical interventions should describe the incidence of side-effects numerically. Evidence suggests that clinicians should take particular care with patients with lower quality of life, who are currently experiencing symptoms and who have previously experienced symptoms from treatment. Further research should investigate different clinical populations and aim to quantify the impact of the media and social media on side-effect expectations.

'Measuring up': A comparison of two response expectancy assessment formats completed by men treated with radiotherapy for prostate cancer

OBJECTIVE

Response expectancies of cancer treatment toxicities are often, but not always, associated with subsequent experiences. A recent meta-analysis indicated that response expectancies, measured using different assessment formats, reveal different effect sizes, potentially explaining mixed outcomes. Utilizing a clinical sample, we compared 5-point assessments and visual analogue scales, as measures of response expectancies for the incidence and severity of subsequent toxicities.

METHODS

Four weeks pre-radiotherapy, 45 men with prostate cancer rated their response expectancies of the same 18 toxicities on 5-point assessments and visual analogue scales, presented in random order. Descriptors anchored each end of visual analogue scales and every point of 5-point assessments was labelled, including an 'unsure' midpoint. Toxicities were subsequently assessed 2-weeks into radiotherapy on 100-point visual analogue scales.

RESULTS

Across all toxicities, 17.5-62.8% of patients selected 'unsure' on 5-point assessments. No response expectancies were reported on 5-point assessments for 'blood in stools' or 'rectal urgency' yet 54.8%-64.3% of patients indicated response expectancies for these toxicities on visual analogue scales. Visual analogue scales and 5-point scales demonstrated small-to-moderate associations (r = 0.30-0.58) as measures of response expectancy incidence, but mostly large associations when visual analogue scales captured severity (r = 0.43-0.76). Response expectancies measured with visual analogue scales predicted more toxicities to a moderate degree or greater (68.8%) than 5-point assessments (37.5%).

CONCLUSION

This novel investigation demonstrated an 'unsure' midpoint is often selected, potentially reducing the sensitivity of 5-point assessments. Based on their associations, and outcomes, these assessment formats should be considered independent in response expectancy research of cancer treatment toxicities.

Anxiety in caregiving partners of breast cancer patients

PURPOSE

The aim of the present study was to determine the levels of anxiety of partners of breast cancer patients and to evaluate the differences of anxiety levels between patients and partners according to the stage of treatment, age and education level.

METHODS

57 spouses or domestic partners of breast cancer patients and 148 breast cancer patients participated in this prospective cohort study and filled out the questionnaires including the Spielberger state-trait-anxiety-inventory, as well as questions based on stress-triggering procedures during breast cancer diagnosis and therapy.

RESULTS

State anxiety levels of partners were highest in partners who accompanied their patients when presenting for examinations and operations and tumorboard decisions (Mean State-Scores 52, 45 and 46.5). Anxiety scores were lowest at the stage of ongoing chemotherapy or follow-up. The 25% quartile of partners with the highest state anxiety levels had a significantly higher educational level (p = 0.023). Young men aged 18-35 years showed the highest levels of both trait and state anxiety. Partners showed significantly higher levels of anxiety than the patients for anesthetic complications (p < 0.001), e.g., fear of not waking up from general anesthetic and postoperative pain (p < 0.001). Patients showed significantly higher levels of anxiety for hairloss (p < 0.001), weight gain during chemotherapy (p < 0.001) and postoperative scars (p = 0.027).

CONCLUSION

Breast cancer patients are much more concerned about body image issues than their male partners. As these body image-associated concerns often arise from the fear of loosing attraction to their partner, these fears might be reduced by speaking about them openly. Partners are mostly concerned about surgery and anesthetic-related complications. Therefore, preoperative medical information to the partner is mandatory. Partners of breast cancer patients should be included in psycho-oncological support and medical briefings. Probably high anxiety levels of both partners and patients should be taken into account (due to younger age, lower educational level and procedures causing distress). These partners and patients should receive extra careful (clarification) counselling and (treatment support such as a psycho-oncologist) involvement of a psyco-oncologist.

Placebo and Nocebo Effects Across Symptoms: From Pain to Fatigue, Dyspnea, Nausea, and Itch

Placebo and nocebo effects are, respectively, the helpful and harmful treatment effects that do not arise from active treatment components. These effects have thus far been researched most often in pain. It is not yet clear to what extent these findings from pain can be generalized to other somatic symptoms. This review investigates placebo and nocebo effects in four other highly prevalent symptoms: dyspnea, fatigue, nausea, and itch. The role of learning mechanisms (verbal suggestions, conditioning) in placebo and nocebo effects on various outcomes (self-reported, behavioral, and physiological) of these different somatic symptoms is explored. A search of experimental studies indicated that, as in pain, the combination of verbal suggestion and conditioning is generally more effective than suggestion alone for evoking placebo and nocebo effects. However, conditioning appears more and verbal suggestions less relevant in symptoms other than pain, with the exception of placebo effects on fatigue and nocebo effects on itch. Physiological measures, such as heart rate, lung function, or gastric activity, are rarely affected even when self-reported symptoms are. Neurobiological correlates are rarely investigated, and few commonalities appear across symptoms. Expectations generally predict placebo and nocebo effects for dyspnea and itch but seem less involved in fatigue and nausea. Individual characteristics do not consistently predict placebo or nocebo effects across symptoms or studies. In sum, many conclusions deriving from placebo and nocebo pain studies do appear to apply to other somatic symptoms, but a number of important differences exist. Understanding what type of learning mechanisms for which symptom are most likely to trigger placebo and nocebo effects is crucial for generalizing knowledge for research and therapies across symptoms and can help clinicians to optimize placebo effects in practice.

Positive effects of acupressure bands combined with relaxation music/instructions on patients most at risk for chemotherapy-induced nausea

PURPOSE

Research by our group has shown that acupressure bands are efficacious in reducing chemotherapy-induced nausea (CIN) for breast cancer patients who expect nausea, and that their effectiveness in controlling CIN can largely be accounted for by patients' expectations of efficacy, i.e., a placebo effect. The present research examined if the effectiveness of acupressure bands could be enhanced by boosting patients' expectation of the bands' efficacy.

METHODS

Two hundred forty-two chemotherapy-naïve patients with breast cancer who expected nausea were randomized. Arms 1 and 2 received acupressure bands, plus a relaxation MP3 and written handout that were either expectancy-enhancing (arm 1) or expectancy-neutral (arm 2). Arm 3 was the control without bands or MP3 and received standard care. All participants received guideline-specified antiemetics.

RESULTS

Peak CIN for arms 1, 2, and 3 on a 1-7 scale was 3.52, 3.55, and 3.87, respectively (p = 0.46). Because no differences were observed between arms 1 and 2 (primary analysis), we combined these two arms (intervention) and compared them to controls for the following analyses. A significant interaction was found between intervention/control and receiving doxorubicin-based chemotherapy (yes/no) and pre-treatment anxiety (high/low). Intervention patients receiving doxorubicin had lower peak CIN than controls (3.62 vs. 4.38; p = 0.02). Similarly, intervention patients with high pre-treatment anxiety had a lower peak CIN than controls (3.62 vs. 4.62; p = 0.01).

CONCLUSIONS

In breast cancer patients undergoing chemotherapy and having high CIN expectation, acupressure bands combined with a relaxation recording were effective in reducing CIN for patients who received doxorubicin or had high anxiety.

Preventing adverse information effects on health outcomes: A self-affirmation intervention reduced information-induced cognitive decline in gastrointestinal cancer patients

RATIONALE

Nocebo studies show that informing patients about treatment side effects can adversely impact expectancies and symptom reporting.

OBJECTIVE

The current study examined how to inform patients fully about treatment side effects without increasing their occurrence. Extending theoretical assumptions about self-affirmation from the social-psychological to the medical domain, we tested whether allowing cancer patients to self-affirm prior to informing them about potential cognitive decline reduced the occurrence of Adverse Information Effects (AIE) on cognitive problem reporting (CPR) and verbal memory performance.

METHOD

Participants were 90 Dutch and Belgian gastrointestinal cancer patients with and without chemotherapy experience. Patients were randomized across three experimental conditions (information about chemotherapy-related cognitive problems with or without self-affirmation; no-information control) before completing an online questionnaire. Data were collected from May until August 2015. Main dependent variables were CPR and verbal memory performance. Stigma consciousness was included as a moderator.

RESULTS

Informing patients about chemotherapy-related cognitive problems increased CPR and decreased scores on two out of three memory measures. Self-affirmation reduced these AIE. Stigma conscious patients reported more problems in the information than the self-affirmation group.

CONCLUSIONS

Nocebo effects may be reduced by allowing patients the opportunity to restore their self-integrity at the implicit level. Self-affirmation has the potential to reduce AIE in patient populations without withholding relevant information about potential treatment side effects.

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

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

Changes in the Occurrence, Severity, and Distress of Symptoms in Patients With Gastrointestinal Cancers Receiving Chemotherapy

CONTEXT

Studies on multiple dimensions of the symptom experience of patients with gastrointestinal cancers are extremely limited.

OBJECTIVE

Purpose was to evaluate for changes over time in the occurrence, severity, and distress of seven common symptoms in these patients.

METHODS

Patients completed Memorial Symptom Assessment Scale, six times over two cycles of chemotherapy (CTX). Changes over time in occurrence, severity, and distress of pain, lack of energy, nausea, feeling drowsy, difficulty sleeping, and change in the way food tastes were evaluated using multilevel regression analyses. In the conditional models, effects of treatment group (i.e., with or without targeted therapy), age, number of metastatic sites, time from cancer diagnosis, number of prior cancer treatments, cancer diagnosis, and CTX regimen on enrollment levels, as well as the trajectories of symptom occurrence, severity, and distress were evaluated.

RESULTS

Although the occurrence rates for pain, lack of energy, feeling drowsy, difficulty sleeping, and change in the way food tastes declined over the two cycles of CTX, nausea and numbness/tingling in hands/feet had more complex patterns of occurrence. Severity and distress ratings for the seven symptoms varied across the two cycles of CTX.

CONCLUSIONS

Demographic and clinical characteristics associated with differences in enrollment levels as well as changes over time in occurrence, severity, and distress of these seven common symptoms were highly variable. These findings can be used to identify patients who are at higher risk for more severe and distressing symptoms during CTX and to enable the initiation of preemptive symptom management interventions.

Cancer Treatment Side Effects: A Meta-analysis of the Relationship Between Response Expectancies and Experience

CONTEXT

Although previous research has, overall, suggested a moderate relationship between response expectancies (REs) and cancer treatment-related side effects, empirical results have been mixed.

OBJECTIVES

We aimed to further explore these relationships, hypothesizing that REs would predict subsequent toxicities with the inclusion of more recent studies, across a broader range of side effects, while incorporating the impact of potential moderators including patients' experience with treatment and measurement methods. We further investigated the impact of REs across individual toxicities.

METHODS

A systematic search and analysis were conducted across four databases (PsychInfo, PubMed, CINAHL, and Embase) and reference lists, from 1985 to February 2016. This provided 27 eligible studies with 4474 participants, through which the main analysis, moderator analyses, and individual side-effect analyses were explored.

RESULTS

REs were moderately related to side effects overall (r = 0.26), and effect sizes were significantly influenced by sample diagnostic homogeneity, whereas differences between type and timing of measurement showed trends. Of the 16 toxicities examined, 15 demonstrated significant relationships between REs and side-effect experience, with hair loss (r = 0.48) the strongest. No clear difference emerged between objective and subjective side effects; however, significant differences across individual toxicities were revealed.

CONCLUSION

Findings support a relationship between REs and a wide range of subsequent side effects, yet differences between individual RE-toxicity associations emerged. These findings provide direction for the measurement of side effects and REs and support REs as potential targets for intervention during the informed consent process.

Integrative review of factors related to the nursing diagnosis nausea during antineoplastic chemotherapy

Objective

to identify factors related to the nursing diagnosis nausea among cancer patients undergoing chemotherapy.

Method

integrative review conducted in four electronic databases (PUBMED, EMBASE, CINAHL and LILACS) using the key words: neoplasia, antineoplastic agents and nausea.

Results

only 30 out of 1,258 papers identified met the inclusion criteria. The most frequent related factors were: being younger than 50 years old, motion sickness, being a woman, emetogenic potential of the chemotherapy, anxiety, conditioned stimulus, and expecting nausea after treatment.

Conclusion

this review's findings, coupled with the incidence of nausea among cancer patients undergoing chemotherapy, reveal an important difference between evidence found and that used by NANDA International, Inc. Even though it provides an appropriate definition of related factors, it does not mention chemotherapy, despite the various studies addressing the topic using different designs and presenting various objectives and outcomes.

Sources of Placebo-Induced Relief From Nausea: The Role of Instruction and Conditioning

OBJECTIVES

It is well documented that expectancies alter the nauseous response. However, the lack of integration in research examining sources of expectancy has limited our understanding of how expectancies are formed and, consequently, our ability to intervene. The present study explored the role of both instructions and conditioning in placebo-induced relief from nausea.

METHODS

The study used a 2 × 2 between-subjects design with instruction and conditioning as factors with 56 healthy volunteers. The instruction manipulation involved randomizing participants to receive information that a sham treatment (a peppermint essence vapor) would reduce nausea or no such instructions. The conditioning manipulation involved further randomizing participants to have the first administration of this sham treatment paired with a surreptitious reduction in galvanic vestibular stimulation (GVS) intensity or no prior pairing. Nausea was induced through GVS. On test, all groups received the same level of GVS with the sham treatment present.

RESULTS

On test, participants who received instruction had significantly lower nauseous response scores than those who did not (F(1,46) = 6.71, p = .013), and those who received conditioning also reported less nausea than those who did not (F(1,46) = 5.20, p = .027), with the interaction between the two not reaching statistical significance (F(1,46) = 2.33, p = .13).

CONCLUSIONS

These findings indicate that placebo responding in nausea can be induced both through positive instructions and as little as one pairing of a treatment with a reduction in nausea, as well as their combination. This suggests that using placebo effects to complement antiemetic therapy may offer an important method of further reducing nausea in the clinic.

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

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

Placebo effects and their determinants in gastrointestinal disorders

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

The placebo effect, sleep difficulty, and side effects: a balanced placebo model

Medical treatment is usually accompanied by a warning about potential side effects. While constituting an important component of informed consent, these warnings may themselves contribute to side effects via the placebo effect. We tested this possibility using a 2 × 2 between-subjects design. Under the guise of a trial of a new hypnotic, 91 undergraduates experiencing difficulty sleeping were allocated to receive a warning about a target side effect (either increase or decrease in appetite, counterbalanced) or no warning and then to receive placebo treatment or no treatment for one week. Placebo treatment led to significantly better sleep on almost all self-reported outcomes, suggesting a placebo effect for reported sleep difficulty. Actigraphy recordings were unaffected by treatment. There was a clear effect of the warning in that placebo treated participants who were warned about side effects were much more likely to report the target side effect than those not warned about side effects. Implications for clinical practice are discussed.

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

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

Individual differences in chemotherapy-induced anticipatory nausea

Anticipatory Nausea (AN) is a severe side effect of chemotherapy that can lead cancer patients to discontinue their treatment. This kind of nausea is usually elicited by the re-exposure of the patients to the clinical context they need to attend to be treated. There has been considerable agreement that AN represents a paradigmatic example of Pavlovian conditioning, and within this framework, several behavioral interventions have been proposed in order to prevent this phenomenon. However, some studies have questioned the validity of the Pavlovian approach, suggesting that CS-US associations are neither necessary nor sufficient for AN to occur. The data and the alternative theories behind such criticisms are discussed. Additionally, it is suggested that animal models of AN could be enriched by taking into account rats' individual differences.

Does assessing patients' expectancies about chemotherapy side effects influence their occurrence?

CONTEXT

Increasing evidence suggests a link between patients' expectancies and post-chemotherapy side effects. However, it remains unclear whether asking patients about their expectancies might actually increase side effects.

OBJECTIVES

The present study tested whether questioning first-time chemotherapy patients about their pretreatment expectancies for four common side effects influences the occurrence and/or severity of these side effects post-treatment and whether these pretreatment expectancies are predictive of post-treatment side effects.

METHODS

Ninety-one first-time chemotherapy patients were randomly allocated to have their expectancies for nausea, fatigue, feelings of sadness, and loss of appetite assessed before their first infusion or to no such assessment. All patients then rated the occurrence and severity of these side effects at the end of their first chemotherapy cycle.

RESULTS

There were no statistically significant differences in occurrence or severity of side effects in those who had their expectancies assessed compared with those who did not. There was, however, evidence of a statistically significant positive relationship between patients' pretreatment expectancies and their post-treatment reports of nausea, loss of appetite, and feelings of sadness, after controlling for age, sex, and baseline symptom levels.

CONCLUSION

These findings suggest that patient expectancies might be a useful point of intervention for attempting to reduce the burden of chemotherapy-related side effects, as there do not appear to be any detrimental effects of asking patients to report their expectancies and their expectancies do appear related to the occurrence of post-treatment side effects.

Warning about side effects can increase their occurrence: an experimental model using placebo treatment for sleep difficulty

Patients in clinical practice and participants in clinical trials are warned about side effects that may result from their treatment. Such warnings could lead to placebo-induced side effects if they create an expectation of these effects. We used an experimental model to test this possibility. Undergraduates reporting sleep difficulty received placebo treatment disguised as a hypnotic for one week and were warned about either one or four bogus side effects. Placebo treatment significantly improved sleep difficulty relative to a no treatment control group, as indicated by self-report and by objective outcomes. At the end of the treatment week participants who had been warned about a single side effect showed better recall of this effect than those warned about four side effects. Most importantly, participants tended to report experiencing a side effect they had been warned about, with a trend towards a larger effect in participants warned about one side effect. This evidence for placebo-induced side effects may need to be considered when interpreting data on side effects from clinical trials.

The nocebo effect and its relevance for clinical practice

Negative expectations deriving from the clinical encounter can produce negative outcomes, known as nocebo effects. Specifically, research on the nocebo effect indicates that information disclosure about potential side effects can itself contribute to producing adverse effects. Neurobiological processes play a role in the nocebo effect, and this article provides a selective review of mechanistic research on the nocebo effect. Comparatively little attention has been directed to clinical studies and their implications for daily clinical practice. The nocebo response is influenced by the content and the way information is presented to patients in clinical trials in both the placebo and active treatment conditions. Nocebo effects adversely influence quality of life and therapy adherence, emphasizing the need for minimizing these responses to the extent possible. Evidence further indicates that the informed consent process in clinical trials may induce nocebo effects. This article concludes with ethical directions for future patient-oriented research and routine practice.

Patient expectancy and post-chemotherapy nausea: a meta-analysis

BACKGROUND

Post-chemotherapy nausea remains a significant burden to cancer patients. While some studies indicate that expecting nausea is predictive of experiencing nausea, there are a number of conflicting findings.

PURPOSE

The purpose of this study was to conduct a meta-analytic review to determine the strength of the relationship between expectancy and post-chemotherapy nausea.

METHODS

The findings from 17 relevant studies (n = 2,400) identified through systematic searches of Medline, PsycInfo, and Cinhal were analyzed using a combination of meta-analytic techniques.

RESULTS

Overall, there was a robust positive association between expectancy and post-chemotherapy nausea (ESr = 0.18, equivalent to Cohen's d = 0.35), suggesting that patients with stronger expectancies experience more chemotherapy-induced nausea. Although weaker associations were found in studies employing multivariate analysis, specifically controlling for a history of nausea, and involving breast cancer patients, none of the moderators assessed were statistically significant.

CONCLUSIONS

These findings suggest that patient expectancies may contribute to post-chemotherapy nausea and that expectancy-based manipulations may provide a useful intervention strategy.

Dispositional optimism predicts placebo analgesia

Based on prior research identifying dispositional optimism as a predictor of placebo responding, the present study tested the hypothesis that individuals high in optimism would be more likely to respond to a placebo analgesic. Optimists and pessimists were randomly assigned to a placebo expectation condition or a no expectation condition before a cold pressor task. Blood pressure and heart rate were recorded before and during the cold pressor task, and participant ratings of pain and expectations were obtained immediately after the task. Analysis of the expectation manipulation revealed that the placebo instruction was successful in altering participant expectancy during the cold pressor. Supporting the main hypothesis, dispositional optimism was associated with lower pain ratings in the placebo condition but not in the control condition. Because dispositional optimism can alter placebo responding to laboratory pain, future studies should examine the potential role that this individual difference factor may play in patient responsivity to pharmacological and nonpharmacological treatments for clinical pain.

PERSPECTIVE

This study examined the possibility that individual differences can predict placebo analgesia. Participants were randomly assigned to receive either a placebo expectation or no expectation before a cold pressor task. Dispositional optimism was related to less cold pressor pain in the placebo condition as compared with the control condition.

An exploratory study on the effects of an expectancy manipulation on chemotherapy-related nausea

CONTEXT

Previous research has shown that the effectiveness of acupressure bands in reducing chemotherapy-related nausea is related to patients' expectations of efficacy.

OBJECTIVE

To test whether an informational manipulation designed to increase expectation of efficacy regarding acupressure bands would enhance their effectiveness.

METHODS

We conducted an exploratory, four-arm, randomized clinical trial in breast cancer patients about to begin chemotherapy. All patients received acupressure bands and a relaxation CD. This report focuses on Arm 1(expectancy-neutral informational handout and CD) compared with Arm 4 (expectancy-enhancing handout and CD). Randomization was stratified according to the patient's level of certainty that she would have treatment-induced nausea (two levels: high and low). Experience of nausea and use of antiemetics were assessed with a five-day diary.

RESULTS

Our expectancy-enhancing manipulation resulted in improved control of nausea in the 26 patients with high nausea expectancies but lessened control of nausea in 27 patients having low nausea expectancies. This interaction effect (between expected nausea and intervention effectiveness) approached statistical significance for our analysis of average nausea (P=0.084) and reached statistical significance for our analysis of peak nausea (P=0.030). Patients receiving the expectancy-enhancing manipulation took fewer antiemetic pills outside the clinic (mean(enhanced)=12.6; mean(neutral)=18.5, P=0.003).

CONCLUSION

This exploratory intervention reduced antiemetic use overall and also reduced nausea in patients who had high levels of expected nausea. Interestingly, it increased nausea in patients who had low expectancies for nausea. Confirmatory research is warranted.

A meta-analysis of the relationship between response expectancies and cancer treatment-related side effects

Response expectancies, defined as expectations for nonvolitional responses, have been proposed to contribute to the experience of side effects of cancer and its treatment. To statistically evaluate this association, a systematic search of the published literature was conducted, resulting in 14 studies appropriate for meta-analysis. Results revealed a significant (Z=6.58, P<0.001) medium-sized (r=0.36) association between patients' response expectancies for cancer treatment-related side effects and the experience of these side effects. Assessment of response expectancies with reference to the time the treatment-related side effect would occur resulted in larger effect sizes than when such temporal specificity in assessment was not included, Q(1)=10.27, P<0.01. Effect sizes were also moderated by patients' prior experience with cancer treatment, Q(1)=18.91, P=0.001, such that prior experience led to stronger associations between response expectancies and side effects than no prior experience. Relationships between response expectancies and pain, fatigue, nausea, and vomiting were explored. Effect sizes did not differ between side effects, with the exception that the relationship was significantly stronger for pain than for vomiting (P<0.05). Overall, these results support the contribution of response expectancies to cancer treatment-related side effects. Additionally, the results support the conduct of research on interventions to alter response expectancies, with the goal of reducing side effects and improving patient quality of life.

Acupressure bands are effective in reducing radiation therapy-related nausea

Previous studies have shown that acupressure bands can reduce chemotherapy-related nausea. Patients' expectations of efficacy account for part of this outcome. We conducted a three-arm randomized clinical trial to investigate the effectiveness of acupressure bands in controlling radiation therapy-induced nausea and to test whether an informational manipulation designed to increase expectation of efficacy would enhance the effectiveness of the acupressure bands. Patients who experienced nausea at prior treatments were randomized to either standard care (Arm 1, n=29) or standard care plus acupressure bands with either neutral (Arm 2, n=30) or positive (Arm 3, n=29) information regarding the efficacy of the bands. Patients reported nausea for two days prior to randomization (baseline) and for five days following using a seven-point semantic rating scale (1=not nauseated to 7=extremely nauseated). Patients in Arms 2 and 3 combined reported greater reduction in average nausea than patients in Arm 1 (P=0.01; mean(bands)=0.70, mean(no bands)=0.10). This equates to a 23.8% decrease in nausea in the band groups compared to a 4.8% decrease in the control group, a 19% difference. The informational manipulation failed to alter efficacy expectations and there was no statistically significant difference in nausea between patients in Arms 2 and 3. Acupressure bands are an effective, low-cost, nonintrusive, well-accepted, and safe adjunct to standard antiemetic medication. An attempt to boost the efficacy of the acupressure bands by providing positive information was not successful.

Insight in the prediction of chemotherapy-induced nausea

PURPOSE

To identify risk factors for chemotherapy-related nausea.

METHODS

We examined risk factors for nausea in 1,696 patients from three multicenter studies conducted from 1998 to 2004. All patients were beginning a chemotherapy regimen containing cisplatin, carboplatin, or doxorubicin. Nausea was assessed on a 1-7 scale four times a day for 4 days by diary.

RESULTS

First, average nausea for breast cancer patients receiving doxorubicin (mean = 2.31) was significantly greater than for other patients receiving doxorubicin (mean = 1.82), patients receiving cisplatin (mean = 1.88), and patients receiving carboplatin (mean = 1.45), Ps < 0.01. Second, mean nausea decreased steadily with age, P < 0.0001. Third, patients rating themselves more susceptible to nausea had significantly more nausea (adjusted mean = 2.51) than patients rating themselves less susceptible (adjusted mean = 1.92) and were 2.8 times more likely to experience severe nausea, Ps < 0.0001. Fourth, expected nausea was a significant predictor of average nausea, P = 0.034, but not severe nausea, P = 0.31. Last, no evidence that gender is a significant predictor of nausea in 299 patients with gender neutral cancers, P = 0.35.

CONCLUSIONS

Specific patient characteristics, especially younger age and perceived susceptibility to nausea, can help clinicians in the early identification of patients who are more susceptible to treatment-related nausea.