Relieving patients' pain with expectation interventions: a meta-analysis

An umbrella review of the literature on the effectiveness of psychological interventions for pain reduction

BACKGROUND

Psychological interventions are widely implemented for pain management and treatment, but their reported effectiveness shows considerable variation and there is elevated likelihood for bias.

METHODS

We summarized the strength of evidence and extent of potential biases in the published literature of psychological interventions for pain treatment using a range of criteria, including the statistical significance of the random effects summary estimate and of the largest study of each meta-analysis, number of participants, 95% prediction intervals, between-study heterogeneity, small-study effects and excess significance bias.

RESULTS

Thirty-eight publications were identified, investigating 150 associations between several psychological interventions and 29 different types of pain. Of the 141 associations based on only randomized controlled trials, none presented strong or highly suggestive evidence by satisfying all the aforementioned criteria. The effect of psychological interventions on reducing cancer pain severity, pain in patients with arthritis, osteoarthritis, rheumatoid arthritis, breast cancer, fibromyalgia, irritable bowel syndrome, self-reported needle-related pain in children/adolescents or with chronic musculoskeletal pain, chronic non-headache pain and chronic pain in general were supported by suggestive evidence.

CONCLUSIONS

The present findings reveal the lack of strong supporting empirical evidence for the effectiveness of psychological treatments for pain management and highlight the need to further evaluate the established approach of psychological interventions to ameliorate pain.

Explicit Education About Exercise-Induced Hypoalgesia Influences Pain Responses to Acute Exercise in Healthy Adults: A Randomized Controlled Trial

The mechanisms through which acute exercise reduces pain (ie, exercise-induced hypoalgesia [EIH]) are poorly understood. This study aimed to determine if education about EIH affected pain responses after acute exercise in healthy adults. Participants received 15 minutes of education either about EIH (intervention, n = 20) or more general education about exercise and pain (control, n = 20). After this, the participants' knowledge and beliefs about exercise and pain were assessed. Pressure pain thresholds were then measured before and after 20 minutes of cycle ergometer exercise. Compared with the control group, the intervention group believed more strongly that pain could be reduced by a single session of exercise (P = .005) and that the information they had just received had changed what they thought about the effect of exercise on pain (P = .045). After exercise, pressure pain threshold increased in both groups, but the median increase was greater in the intervention group compared with the control group (intervention = .78 kg/cm², control = .24 kg/cm², P = .002, effect size [r] of difference = .49). These results suggest that cognitive processes in the appraisal of pain can be manipulated to influence EIH in healthy adults.

PERSPECTIVE

This study shows that preceding a bout of exercise with pain education can alter pain responses after exercise. This finding has potential clinical implications for exercise prescription for people with chronic pain whereby pain education before exercise could be used to improve pain responses to that exercise.

What techniques might be used to harness placebo effects in non-malignant pain? A literature review and survey to develop a taxonomy

OBJECTIVES

Placebo effects can be clinically meaningful but are seldom fully exploited in clinical practice. This review aimed to facilitate translational research by producing a taxonomy of techniques that could augment placebo analgesia in clinical practice.

DESIGN

Literature review and survey.

METHODS

We systematically analysed methods which could plausibly be used to elicit placebo effects in 169 clinical and laboratory-based studies involving non-malignant pain, drawn from seven systematic reviews. In a validation exercise, we surveyed 33 leading placebo researchers (mean 12 years’ research experience, SD 9.8), who were asked to comment on and add to the draft taxonomy derived from the literature.

RESULTS

The final taxonomy defines 30 procedures that may contribute to placebo effects in clinical and experimental research, proposes 60 possible clinical applications and classifies procedures into five domains: the patient’s characteristics and belief (5 procedures and 11 clinical applications), the practitioner’s characteristics and beliefs (2 procedures and 4 clinical applications), the healthcare setting (8 procedures and 13 clinical applications), treatment characteristics (8 procedures and 14 clinical applications) and the patientâ€"practitioner interaction (7 procedures and 18 clinical applications).

CONCLUSION

The taxonomy provides a preliminary and novel tool with potential to guide translational research aiming to harness placebo effects for patient benefit in practice.

Placebo-like analgesia via response imagery

BACKGROUND

Placebo effects on pain are reliably observed in the literature. A core mechanism of these effects is response expectancies. Response expectancies can be formed by instructions, prior experiences and observation of others. Whether mental imagery of a response can also induce placebo-like expectancy effects on pain has not yet been studied systematically.

METHODS

In Study 1, 80 healthy participants were randomly allocated to (i) response imagery or (ii) control imagery. In Study 2, 135 healthy participants were randomly allocated to (i) response imagery with a verbal suggestion regarding its effectiveness, (ii) response imagery only, or (iii) no intervention. In both studies, expected and experienced pain during cold pressor tests were measured pre- and post-intervention, along with psychological and physiological measures.

RESULTS

Participants rated pain as less intense after response imagery than after control imagery in Study 1 (p = 0.044, ηp2 = 0.054) and as less intense after response imagery (with or without verbal suggestion) than after no imagery in Study 2 (p < 0.001, ηp2 = 0.154). Adding a verbal suggestion did not affect pain (p = 0.068, ηp2 = 0.038). The effects of response imagery on experienced pain were mediated by expected pain.

CONCLUSIONS

Thus, in line with research on placebo effects, the current findings indicate that response imagery can induce analgesia, via its effects on response expectancies.

SIGNIFICANCE

The reported studies extend research on placebo effects by demonstrating that mental imagery of reduced pain can induce placebo-like expectancy effects on pain.

Nocebo effects in clinical studies: hints for pain therapy

INTRODUCTION

Nocebo-induced algesic responses occurring within clinical contexts present a challenge for health care practitioners working in the field of pain medicine.

OBJECTIVES

Following the recent research on algesic nocebo effects, the scope of this review is to develop ethically acceptable strategies to help avoid, or at least reduce, nocebo responses within clinical settings.

METHODS

We reviewed relevant clinical studies that depict how patient-practitioner interactions may contribute to the reduction of nocebo responses.

RESULTS

A strong algesic nocebo effect may adversely impact a patient's condition by causing decreases in both the efficacy and effectiveness of interventions, as well as by promoting treatment nonadherence and discontinuation. These effects may be triggered through multiple channels and can lead to significant alterations in a patient's perception of pain, consequently producing a weakening of the specific positive effects of pharmacological, psychological, or physical pain-management interventions.

CONCLUSION

To minimize nocebo effects in clinical settings, we identified and discussed five contextual aspects relevant to the treatment of patients with chronic pain: (1) negative patient-clinician communication and interaction during treatment; (2) emotional burden of patients during treatment with analgesic medication; (3) negative information provided via informational leaflets; (4) cued and contextual conditioning nocebo effects; and (5) patient's lack of positive information. Through an understanding of these elements, many preventive and ethically acceptable clinical actions can be taken to improve multidisciplinary pain treatment outcomes.

Context as a drug: some consequences of placebo research for primary care

OBJECTIVE

On the basis of emerging research evidence, this review aims to discuss the importance of the context surrounding the doctor-patient encounter for the success of treatment.

DESIGN AND SETTING

Discussion paper based on placebo-nocebo and pain studies conducted in the western world.

MAIN OUTCOME MEASURES

Literature-based theory about impact of communication elements on seriousness of symptoms in clinical practice.

RESULTS

The therapeutic outcome seems to be impacted by rituals around a clinical encounter and by the doctor patient communication and relation. A warm, friendly and empathic attitude is crucial in the first contact with the practice and during the consultation as it influences the patient's perceived outcome. It is important to raise positive expectations when discussing the prognosis, conducting treatment and prescribing medications as the effect may be reduced if the physician expresses doubt about the effectiveness of the medication. Additionally, overly focus on side effects in the doctor-patient conversation about proposed treatments seems to influence the magnitude of perceived side effects in the patient. Thus, shared decision-making might be a desirable tool for ensuring better expectations in the patient and successful symptom relief.

CONCLUSIONS

The context of the doctor-patient interplay matters. Placebo-nocebo research provides strong evidence for this link. The therapeutic context induces biomedical processes in the patient's brain that may enhance or reduce the effects of chosen interventions. The context thus works as a drug, with real effects and side effects. KEY POINTS Increased awareness of the context drug may help GPs alleviate symptoms and better motivate patients for treatment. Treatment is affected by multiple types of context, as also confirmed by placebo-nocebo research. The therapeutic context influences the biomedical processes, which may enhance or reduce intervention effects on symptoms. The impact of context should be considered in daily general practice as it may serve as a drug, with real effects and side effects.

The role of psychological factors in inflammatory rheumatic diseases: From burden to tailored treatment

Inflammatory rheumatic diseases have a long-lasting effect on patients' physical and psychological functioning, for instance, due to disabling symptoms and unpredictable disease course. Consequently, many patients show adjustment problems such as depressed mood, which in turn can negatively influence their disease outcome. Specific biopsychosocial factors have shown to affect this outcome. For example, daily stress, cognitive-behavioral risk factors such as pain catastrophizing and avoidance, and resilience factors such as optimism and social support influence the quality of life, physical symptoms of pain and fatigue, and inflammatory markers. Psychological interventions tackling these factors can have beneficial effects on physical and psychological functioning. Recent advances in screening for patients at risk, tailored treatment, and eHealth further broaden the efficiency and scope of these interventions while simultaneously optimizing patient empowerment. This chapter describes the biopsychosocial risk and resilience factors related to disease outcome and the possible benefits of psychological treatment strategies in inflammatory rheumatic diseases.

Work-Related Factors Considered by Sickness-Absent Employees When Estimating Timeframes for Returning to Work

INTRODUCTION

Work-related factors have been found to be influential in shaping a number of return-to-work outcomes including return-to-work expectations. Based on the idea that work-related factors have the potential for modification through workplace-based initiatives, this study involved a detailed examination of work-related factors referenced by workers as being taken into consideration when estimating timeframes for returning to work.

METHODS

Focus groups were conducted with 30 employees, currently off work (≤ 3 months) due to a musculoskeletal condition. During the focus groups, participants wrote and spoke about the factors that they considered when forming their expectations for returning to work. Data were subjected to thematic content analysis.

RESULTS

Discussions revealed that participants' considerations tended to differ depending on whether or not they had a job to return to. Those with jobs (n = 23) referenced specific influences such as working relationships, accommodations, physical and practical limitations, as well as concerns about their ability to do their job. Those without a job to return to (n = 7) talked about the ways they would go about finding work, and how long they thought this would take. Both groups mentioned the influence of wanting to find the "right" job, retraining and being limited due to the need for income.

CONCLUSION

Findings indicate that employees reference numerous work-related factors when estimating their timeframes for returning to work, and that many of these have been previously identified as relating to other return-to-work outcomes. Findings suggest the potential to improve return-to-work expectation through addressing work-related influences, and helping people work through the tasks they need to complete in order to move forward in the return-to-work process.

An Integrative Review of the Influence of Expectancies on Pain

Expectancies can shape pain experiences. Attention for the influence of expectancies on pain has increased particularly due to research on placebo effects, of which expectancy is believed to be the core mechanism. In the current review, we provide a brief overview of the literature on the influence of expectancies on pain. We first discuss the central role of expectancy in the major psychological learning theories. Based on these theories, different kinds of expectancies can be distinguished. Pain experiences are influenced particularly by response expectancies directly pertaining to the pain experience itself, but can also be affected by self-efficacy expectancies regarding one's ability to cope with pain, and possibly by stimulus expectancies regarding external events. These different kinds of expectancies might interact with each other, and related emotions and cognitions, as reflected by various multifaceted constructs in which expectancies are incorporated. Optimism and pain catastrophizing, in particular, but also hope, trust, worry, and neuroticism have been found to be associated with pain outcomes. We conclude with recommendations for further advancing research on the influence of expectancies on pain and for harnessing expectancy effects in clinical practice.

Enhance placebo, avoid nocebo: How contextual factors affect physiotherapy outcomes

INTRODUCTION

Placebo and nocebo represent complex and distinct psychoneurobiological phenomena in which behavioural and neurophysiological modifications occur together with the application of a treatment. Despite a better understanding of this topic in the medical field, little is known about their role in physiotherapy.

PURPOSE

The aim of this review is: a) to elucidate the neurobiology behind placebo and nocebo effects, b) to describe the role of the contextual factors as modulators of the clinical outcomes in rehabilitation and c) to provide clinical and research guidelines on their uses.

IMPLICATIONS

The physiotherapist's features, the patient's features, the patient-physiotherapist relationship, the characteristics of the treatment and the overall healthcare setting are all contextual factors influencing clinical outcomes. Since every physiotherapy treatment determines a specific and a contextual effect, physiotherapists should manage the contextual factors as a boosting element of any manual therapy to improve placebo effects and avoid detrimental nocebo effects.