Avoidance behavior in chronic pain research: A cold case revisited

Beyond activity patterns: The complex process of activity management among individuals with chronic musculoskeletal pain after an orthopaedic trauma

CONTEXT

Individuals must change the way they perform activities in response to chronic pain. In the literature, three activity patterns are commonly described: avoidance, pacing, and persistence. Many studies have explored these activity patterns. However, little research has delved into the factors that lead people to adopt a particular activity behaviour. This study aimed to explore the relationship that people with chronic musculoskeletal pain have with activity and highlight the factors underlying their practices.

METHODS

The qualitative study was conducted by researchers in the social sciences, physiotherapy, psychology, and rehabilitation medicine. Observations of vocational workshops and semi-structured interviews were conducted with 33 persons undergoing rehabilitation for chronic musculoskeletal pain after an accident.

RESULTS

Patients' declarations and actions show that any one patient will alternate between activity patterns: the same person may adopt a strategy of avoidance, pacing or persistence depending on the context, the importance of the activity, personal objectives, and representations of self, pain, and activity. The decision to engage in a particular behaviour is based on a process of self-negotiation weighted by the circumstances, the nature of the activity, the importance attached to it, and the individual's perceived ability.

CONCLUSION

Our study emphasized the complexity of physical, social, and contextual factors that intervene in the relationship toward activity. Rather than favouring pacing, the therapist's role in rehabilitation might be to reinforce the reflexive process and the patient's adaptability in approaching the activity, to foster the capacity to find flexible solutions.

SIGNIFICANCE

Patients choose an activity pattern (avoidance, pacing, persistence) according to the challenges they face in their daily lives. Context, representations of self and activity, as well as goals sought influence these choices. Some patients report having learned to adapt their activity management strategies. Therefore, therapeutic approaches in the rehabilitation context could focus on these adaptive capacities to offer patients optimal pain and activity management and develop their ability to use different strategies according to the circumstance.

Rewarding Approach Behaviour Attenuates the Return of Pain-Related Avoidance After Successful Extinction with Response Prevention

After successful exposure treatment for chronic pain, pain-related fear and avoidance may return, i.e., relapse may occur. This return of fear and avoidance may be modulated by various post-treatment factors. In this study, we aimed to investigate two potential factors that may affect return of fear and avoidance, i.e. cognitive load and rewarding approach behaviour. In an operant pain-related avoidance conditioning paradigm, healthy pain-free volunteers first learned to fear and avoid an arm-reaching movement that was often paired with painful electrocutaneous stimulation (T1), by performing alternative movements that were less often (T2) or never (T3) paired with pain. During extinction with response prevention, participants were only allowed to perform T1, and pain was omitted. To model relapse, two unexpected painful stimuli were presented (i.e., reinstatement manipulation), after which participants could freely choose among the three arm-reaching movements again. During test, the Low Load group performed an additional easy digit task, whereas the High Load group performed a more cognitively demanding digit task. The Reward group performed the demanding digit task, whilst being rewarded to perform T1. Results showed that pain-related fear and avoidance returned, irrespective of cognitive load imposed. When participants were rewarded to approach T1, however, the return of avoidance, but not fear, was attenuated. Our findings suggest that engaging in rewarding activities may facilitate the maintenance of treatment outcomes, and provide additional support to the growing body of literature indicating a divergent relationship between fear and avoidance. PERSPECTIVE: Results of this experiment suggest that engaging in rewarding activities may optimize exposure treatment for chronic pain, by dampening the return of pain-related avoidance - though not of pain-related fear - after extinction.

Effect of exposure-based vs traditional cognitive behavior therapy for fibromyalgia: a two-site single-blind randomized controlled trial

ABSTRACT

Fibromyalgia is a debilitating pain condition for which treatment effects are typically modest. The most evaluated psychological treatment is traditional cognitive behavior therapy (T-CBT), but promising effects have recently been seen in exposure-based cognitive behavior therapy (Exp-CBT). We investigated whether Exp-CBT was superior to T-CBT in a randomized controlled trial. Self-referred participants with fibromyalgia (N = 274) were randomized (1:1) to 10 weeks of Exp-CBT or T-CBT. Treatments were delivered online and presented as "CBT for fibromyalgia." Participants were assessed at baseline, weekly during treatment, posttreatment, and at 6- and 12-month follow-up. Primary outcome was the difference in reduction in fibromyalgia severity as measured using the Fibromyalgia Impact Questionnaire (FIQ) over 11 assessment points from baseline to posttreatment, modelled within an intention-to-treat framework using linear mixed effects models fitted on multiple imputed data. Approximately 91% of weekly FIQ scores were collected over the main phase. There was no significant difference between Exp-CBT and T-CBT in the mean reduction of fibromyalgia severity from pretreatment to posttreatment (b = 1.3, 95% CI -3.0 to 5.7, P = 0.544, d = -0.10). Minimal clinically important improvement was seen 60% in Exp-CBT vs 59% in T-CBT. Effects were sustained up to 12 months posttreatment. This well-powered randomized trial indicated that Exp-CBT was not superior to T-CBT for fibromyalgia. Both treatments were associated with a marked reduction in fibromyalgia severity, and the online treatment format might be of high clinical utility. T-CBT can still be regarded a reference standard treatment that remains clinically relevant when compared to novel treatment approaches.

Activity-Induced Pain as a Predictor of Sedentary Behavior Among Midlife Adults

Purpose: Midlife adults have been estimated to spend over half of their waking time engaging in sedentary behavior, and greater sedentary behavior has been associated with a reduced likelihood of successful aging. Moreover, more than one-quarter of midlife adults report chronic pain, and there is reason to believe that pain may contribute to sedentary behavior among this population. The goal of these analyses was to test associations between self-reported increases in pain during activity and subsequent sedentary behavior among a sample of midlife adults with chronic pain. Methods: Participants included 200 midlife adults (age 50-64) who reported chronic pain and completed an online prospective survey. Activity-induced pain was assessed at baseline and total time spent engaging in sedentary behavior was assessed at baseline, 1-week, and 4-week follow-up assessments. Results: Activity-induced pain predicted greater sedentary behavior at 1-week (p < .05) and 4-week (p < .01) follow-up assessments, even after controlling for chronic pain intensity and baseline sedentary behavior. Conclusions: Activity-induced pain may represent an important mechanism underlying sedentary behavior among midlife adults with chronic pain, and programs designed to reduce sedentary behavior among this population may benefit from tailoring to account for the antithetical influence of activity-induced pain. Indeed, the current findings suggest that mitigating the extent to which pain increases during activity may be more important than reducing overall pain intensity when attempting to decrease sedentary behavior among this population. This and future work have the potential to inform the refinement of tailored interventions.

High-Anxious People Generalize Costly Pain-Related Avoidance Behavior More to Novel Safe Contexts Compared to Low-Anxious People

Pain-related avoidance is adaptive when there is a bodily threat, but when it generalizes to safe movements/situations, it may become disabling. Both subclinical anxiety-a vulnerability marker for chronic pain-and chronic pain are associated with excessive fear generalization to safe stimuli/situations. Previous research focused mainly on passive fear correlates (psychophysiological arousal and self-reports) leaving avoidance behavior poorly understood. Therefore, we tested whether high-anxious individuals generalize their pain-related avoidance behavior more to novel, safe contexts than low-anxious people. In a robotic-arm-reaching task, both groups (low vs high trait anxiety) performed 1 of 3 movements to reach a target. In the threat context (black background), a painful stimulus could be partly/completely prevented by performing more effortful trajectories (longer and more force needed); in the safe context (white background), no pain occurred. Generalization of avoidance was tested in 2 novel contexts (light/dark gray backgrounds). We assessed pain expectancy, pain-related fear, startle eyeblink responses for all trajectories, and avoidance behavior (ie, maximal deviation from shortest trajectory). Results indicated that differential fear and expectancy selectively generalized to the novel context resembling the original threat context in both groups. Interestingly and in contrast with the verbal reports, high-anxious participants avoided more in the novel context resembling the original safe context, but not in the 1 resembling the threat context. No generalization emerged in the startle data. Because excessive pain-related avoidance specifically may cause withdrawal from daily life activities, these findings suggest that high-anxious individuals may be vulnerable to developing chronic pain disability. PERSPECTIVE: This paper shows that high-anxious people do not overgeneralize pain-related fear and pain expectancy learned in a threat context more to novel, safe contexts than low-anxious individuals, but that they do avoid more in those contexts. These findings suggest that high-anxious individuals may be vulnerable to developing chronic pain disability.

Refocusing of Attention on Positive Events Using Monitoring-Based Feedback and Microinterventions for Patients With Chronic Musculoskeletal Pain in the PerPAIN Randomized Controlled Trial: Protocol for a Microrandomized Trial

BACKGROUND

Chronic musculoskeletal pain (CMSP) affects between 13% and 47% of the population, with a global growth rate of 20.3% within the last 15 years, suggesting that there is a high need for effective treatments. Pain diaries have long been a common tool in nonpharmacological pain treatment for monitoring and providing feedback on patients' symptoms in daily life. More recently, positive refocusing techniques have come to be used, promoting pain-free episodes and positive outcomes rather than focusing on managing the pain.

OBJECTIVE

This study aims to evaluate the feasibility (ie, acceptability, intervention adherence, and fidelity) and initial signals of efficacy of the PerPAIN app, an ecological momentary intervention for patients with CMSP. The app comprises digitalized monitoring using the experience sampling method (ESM) and feedback. In addition, the patients receive 3 microinterventions targeted at refocusing of attention on positive events.

METHODS

In a microrandomized trial, we will recruit 35 patients with CMSP who will be offered the app for 12 weeks. Participants will be prompted to fill out 4 ESM monitoring questionnaires a day assessing information on their current context and the proximal outcome variables: absence of pain, positive mood, and subjective activity. Participants will be randomized daily and weekly to receive no feedback, verbal feedback, or visual feedback on proximal outcomes assessed by the ESM. In addition, the app will encourage participants to complete 3 microinterventions based on positive psychology and cognitive behavioral therapy techniques. These microinterventions are prompts to report joyful moments and everyday successes or to plan pleasant activities. After familiarizing themselves with each microintervention individually, participants will be randomized daily to receive 1 of the 3 exercises or none. We will assess whether the 2 feedback types and the 3 microinterventions increase proximal outcomes at the following time point. The microrandomized trial is part of the PerPAIN randomized controlled trial (German Clinical Trials Register DRKS00022792) investigating a personalized treatment approach to enhance treatment outcomes in CMSP.

RESULTS

Approval was granted by the Ethics Committee II of the University of Heidelberg on August 4, 2020. Recruitment for the microrandomized trial began in May 2021 and is ongoing at the time of submission. By October 10, 2022, a total of 24 participants had been enrolled in the microrandomized trial.

CONCLUSIONS

This trial will provide evidence on the feasibility of the PerPAIN app and the initial signals of efficacy of the different intervention components. In the next step, the intervention would need to be further refined and investigated in a definitive trial. This ecological momentary intervention presents a potential method for offering low-level accessible treatment to a wide range of people, which could have substantial implications for public health by reducing disease burden of chronic pain in the population.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/43376.

Virtual reality to understand pain-associated approach behaviour: a proof-of-concept study

Pain-associated approach and avoidance behaviours are critically involved in the development and maintenance of chronic pain. Empirical research suggests a key role of operant learning mechanisms, and first experimental paradigms were developed for their investigation within a controlled laboratory setting. We introduce a new Virtual Reality paradigm to the study of pain-related behaviour and investigate pain experiences on multiple dimensions. The paradigm evaluates the effects of three-tiered heat-pain stimuli applied contingent versus non-contingent with three types of arm movements in naturalistic virtual sceneries. Behaviour, self-reported pain-related fear, pain expectancy and electrodermal activity were assessed in 42 healthy participants during an acquisition phase (contingent movement-pain association) and a modification phase (no contingent movement-pain association). Pain-associated approach behaviour, as measured by arm movements followed by a severe heat stimulus, quickly decreased in-line with the arm movement-pain contingency. Slower effects were observed in fear of movement-related pain and pain expectancy ratings. During the subsequent modification phase, the removal of the pain contingencies modified all three indices. In both phases, skin conductance responses resemble the pattern observed for approach behaviour, while skin conductance levels equal the pattern observed for the self-ratings. Our findings highlight a fast reduction in approach behaviour in the face of acute pain and inform about accompanying psychological and physiological processes. We discuss strength and limitations of our paradigm for future investigations with the ultimate goal of gaining a comprehensive understanding of the mechanisms involved in chronic pain development, maintenance, and its therapy.

Fear Learning in Genital Pain: Toward a Biopsychosocial, Ecologically Valid Research and Treatment Model

Although fear learning mechanisms are implicated in the development, maintenance, exacerbation, and reduction of genital pain, systematic research on how fear of genital pain emerges, spreads, persists, and reemerges after treatment is lacking. This paper provides an overview of the literature on pain-related fear, integrates the ideas on learning and sexual arousal responding, and specifies the pathways through which compromised learning may contribute to the development and persistence of genital pain. In order to refine theories of genital pain and optimize treatments, we need to adopt a biopsychosocial framework to pain-related fear learning and uncover potential moderators that shape individual trajectories. This involves examining the role of physiological processes, subjective experiences, as well as partner and relational cues in fear acquisition, excessive generalization and impaired safety learning, extinction of fear, counterconditioning, and return of fear. Recent methodological advances in fear conditioning and sex research are promising to enable more symptom-specific and ecologically valid experimental paradigms.

Impact of persistent pain on function, cognition, and well-being of older adults

BACKGROUND

We sought to determine the population-level associations between persistent pain and subsequent changes in physical function, cognitive function, and well-being, outcomes important to older adults.

METHODS

We used data from National Health Aging Trends Study (NHATS) of community-dwelling Medicare beneficiaries age 65+ from 2011 to 2019. We defined "persistent pain" as being bothered by pain in the last month in both the 2011and 2012 interviews and "intermittent" pain including those reporting bothersome pain in one interview only. We used competing risks regression to estimate the association between persistent pain and the development of clinically meaningful declines in physical function, cognitive function, and well-being, adjusting for age, sex, race, education, and marital status at baseline.

RESULTS

Of the 5589 eligible NHATS participants, 38.7% reported persistent pain and 27.8% reported intermittent pain. Over one-third described pain in five or more sites. Over the subsequent 7 years, participants with persistent pain were more likely to experience declines in physical function (64% persistent pain, 59% intermittent pain, 57% no bothersome pain; aHR 1.14, 95% CI 1.05-1.23) and well-being (48% persistent pain, 45% intermittent pain, 44% no bothersome pain; aHR 1.11, 95% CI 1.01-1.21), but were not more likely to experience cognitive decline (25% persistent pain, 24% intermittent pain, 23% no bothersome pain; aHR 1.02, 95% CI 0.90-1.16).

CONCLUSIONS

Persistent pain is common in older adults and occurs in multiple body sites. Persistent pain contributes to meaningful declines in physical function and well-being over 7 years and warrants proactive interventions to mitigate pain.

Quality of life in irritable bowel syndrome: Exploring mediating factors through structural equation modelling

BACKGROUND

Irritable Bowel Syndrome (IBS) negatively influences mental and physical quality of life (QoL), but factors that explain this impact are still unclear. Increasing evidence has associated IBS severity, psychological distress, somatic symptoms, and gastrointestinal (GI)-specific anxiety with QoL in IBS. The aim of this study is to further explore these associations and to analyze potential mediating factors.

METHOD

A total of 1017 IBS patients (69.3% female, mean age 40.6 years) who completed a QoL measure (SF-36) were included in this study. A proportion of these participants (N = 183; 72.7% female, mean age 41.7), who additionally completed psychological distress, somatic symptoms, and GI-specific anxiety measures, was included in the mediation analysis. This analysis was conducted via structural equation modelling to identify factors of importance for generic QoL, using a cross-sectional design.

RESULTS

IBS patients reported lower QoL than what is observed in the general population, in particular regarding role limitations caused by health and emotional functioning, vitality, and social functioning. Female patients scored lower than male patients on most QoL dimensions. The effects of IBS severity on mental and physical QoL were mediated by GI-specific anxiety. In addition to GI-specific anxiety, depressive symptoms were also of importance for mental QoL, and somatic symptom severity for physical QoL.

CONCLUSION

QoL is reduced in patients with IBS and GI-specific anxiety, depressive symptoms, and somatic complaints are particularly important for this outcome. Future trials should test the efficacy of psychological interventions specifically targeting these factors in improving QoL in IBS.

Alike, But Not Quite: Comparing the Generalization of Pain-Related Fear and Pain-Related Avoidance

Pain-related fear and -avoidance crucially contribute to pain chronification. People with chronic pain may adopt costly avoidance strategies above and beyond what is necessary, aligning with experimental findings of excessive fear generalization to safe movements in these populations. Furthermore, recent evidence suggests that, when avoidance is costly, it can dissociate from fear. Here, we investigated whether concurrently measured pain-related fear and costly avoidance generalization correspond in one task. We also explored whether healthy participants avoid excessively despite associated costs, and if avoidance would decrease as a function of dissimilarity from a pain-associated movement. In a robotic arm-reaching task, participants could avoid a low-cost, pain-associated movement trajectory (T+), by choosing a high-cost non-painful movement trajectory (T-), at opposite ends of a movement plane. Subsequently, in the absence of pain, we introduced three movement trajectories (G1-3) between T+ and T-, and one movement trajectory on the side of T- opposite to T+ (G4), linearly increasing in costs from T+ to G4. Avoidance was operationalized as maximal deviation from T+, and as trajectory choice. Fear learning was measured using self-reported pain-expectancy, pain-related fear, and startle eye-blink electromyography. Self-reports generalized, both decreasing with increasing distance from T+. In contrast, all generalization trajectories were chosen equally, suggesting that avoidance-costs and previous pain balanced each other out. No effects emerged in the electromyography. These results add to a growing body of literature showing that (pain-related) avoidance, especially when costly, can dissociate from fear, calling for a better understanding of the factors motivating, and mitigating, disabling avoidance. PERSPECTIVE: This article presents a comparison of pain-related fear- and avoidance generalization, and an exploration of excessive avoidance in healthy participants. Our findings show that pain-related avoidance can dissociate from fear, especially when avoidance is costly, calling for a better understanding of the factors motivating and mitigating disabling avoidance.

Individual Patterns and Temporal Trajectories of Changes in Fear and Pain during Exposure In Vivo: A Multiple Single-Case Experimental Design in Patients with Chronic Pain

Exposure in vivo (EXP) is an effective treatment to reduce pain-related fear and disability in chronic pain populations. Yet, it remains unclear how reductions in fear and pain relate to each other. This single-case experimental design study attempted to identify patterns in the individual responses to EXP and to unravel temporal trajectories of fear and pain. Daily diaries were completed before, during and after EXP. Multilevel modelling analyses were performed to evaluate the overall effect. Temporal effects were scrutinized by individual regression analyses and determination of the time to reach a minimal clinically important difference. Furthermore, individual graphs were visually inspected for potential patterns. Twenty patients with chronic low back pain and complex regional pain syndrome type I were included. On a group level, both fear and pain were reduced following EXP. Individually, fear was significantly reduced in 65% of the patients, while pain in only 20%. A decrease in fear was seen mostly in the first weeks, while pain levels reduced later or remained unchanged. Daily measurements provided rich data on temporal trajectories of reductions in fear and pain. Overall, reductions in fear preceded pain relief and seemed to be essential to achieve pain reductions.

The Good, the Bad, and the Ugly-Chances, Challenges, and Clinical Implications of Avoidance Research in Psychosomatic Medicine

Avoidance behaviors are shaped by associative learning processes in response to fear of impending threats, particularly physical harm. As part of a defensive repertoire, avoidance is highly adaptive in case of acute danger, serving a potent protective function. However, persistent or excessive fear and maladaptive avoidance are considered key factors in the etiology and pathophysiology of anxiety- and stress-related psychosomatic disorders. In these overlapping conditions, avoidance can increase the risk of mental comorbidities and interfere with the efficacy of cognitive behavioral treatment approaches built on fear extinction. Despite resurging interest in avoidance research also in the context of psychosomatic medicine, especially in conditions associated with pain, disturbed interoception, and disorders of the gut-brain axis, current study designs and their translation into the clinical context face significant challenges limiting both, the investigation of mechanisms involved in avoidance and the development of novel targeted treatment options. We herein selectively review the conceptual framework of learning and memory processes, emphasizing how classical and operant conditioning, fear extinction, and return of fear shape avoidance behaviors. We further discuss pathological avoidance and safety behaviors as hallmark features in psychosomatic diseases, with a focus on anxiety- and stress-related disorders. Aiming to emphasize chances of improved translational knowledge across clinical conditions, we further point out limitations in current experimental avoidance research. Based on these considerations, we propose means to improve existing avoidance paradigms to broaden our understanding of underlying mechanisms, moderators and mediators of avoidance, and to inspire tailored treatments for patients suffering from psychosomatic disorders.

When Do We Not Face Our Fears? Investigating the Boundary Conditions of Costly Pain-Related Avoidance Generalization

Excessive generalization of fear and avoidance are hallmark symptoms of chronic pain disability, yet research focusing on the mechanisms underlying generalization of avoidance specifically, is scarce. Two experiments investigated the boundary conditions of costly pain-related avoidance generalization in healthy participants who learned to avoid pain by performing increasingly effortful (in terms of deviation and force) arm-movements using a robot-arm (acquisition). During generalization, novel, but similar arm-movements, without pain, were tested. Experiment 1 (N = 64) aimed to facilitate generalization to these movements by reducing visual contextual changes between acquisition and generalization, whereas Experiment 2 (N = 70) aimed to prevent extinction by increasing pain uncertainty. Both experiments showed generalization of pain-expectancies and pain-related fear. However, Experiment 2 was the first and only to also demonstrate generalization of avoidance, ie, choosing the novel effortful arm-movements in the absence of pain. These results suggest that uncertainty about the occurrence of pain may delay recovery, due to reduced disconfirmation of threat beliefs when exploring, resulting in persistent avoidance. PERSPECTIVE: This article demonstrates generalization of instrumentally acquired costly pain-related avoidance in healthy people under conditions of uncertainty. The results suggest that targeting pain-related uncertainty may be a useful tool for clinicians adopting a psychological approach to treating excessive pain-related avoidance in chronic pain.

Pain psychology in the 21st century: lessons learned and moving forward

Background and aims In the spring of 2019, Professor Steven J. Linton, the founder of the Center for Health and Medical Psychology (CHAMP) at Örebro University, Sweden, formally retired. As a tribute to his scholarly work covering decades of influence and inspiration to the field of pain psychology, the research center organized a topical conference titled "Pain in the 21st century: Where do we come from and where are we going?", which resulted in this state-of the-art synthesis. The aim of this declaration is to highlight lessons learned but not in the least is meant to inspire and guide our continued journey forward, developing pain psychology into the 21st century. Methods Several collaborators of Professor Linton have summarized and reflected on the current state-of-the-art of pain psychology from the perspective of his input to the field, as well as on developments from the last years of advancements in pain psychology. Results The topics have been divided into six themed sections covering the fear avoidance model, transdiagnostics, secondary prevention, risk- and protective factors, communication and contextual factors. The sections cover a broad spectrum, from basic experimental studies, integrating emotion and motivational theories into current theoretical models, to applied research on the effect of early interventions as well as sophisticated emotion-focused treatment models for pain patients with concurrent emotional ill-health. Conclusions There have been major advancements within pain psychology research during the last decades, moving the field towards a more comprehensive picture, taking emotional and motivational aspects into account to understand pain sufferers. Although psychologically informed interventions in general mainly focus on the individual, it has been put forward that pain management is highly influenced by the surrounding environment, including communication with health care providers, and the occupational and social context. Implications Professor Steven J. Linton has been at the forefront of pain psychology research during the last decades, and inspired by his work this journey will continue into the 21st century, with the ultimate goal of enhancing the understanding and treatment for all people suffering from persistent and disabling pain.

How to objectively assess and observe maladaptive pain behaviors in clinical rehabilitation: a systematic search and review

Background

Cognitive-affective factors influence the perception of pain and disability. These factors can lead to pain behaviors (PB) that can persist and become maladaptive. These maladaptive PB will further increase the risk of chronicity or persistence of symptoms and disability. Thus, clinicians must be prepared to recognize maladaptive PB in a clinical context. To date, in the context of assessment in a rehabilitation setting, PB in clinical settings are poorly documented. The main objective of this study was to identify direct observation methods and critically appraise them in order to propose recommendations for practice. As a secondary objective, we explored and extracted the different observable PB that patients could exhibit and that clinicians could observe.

Methods

We conducted a comprehensive review on four databases with a generic search strategy in order to obtain the largest range of PB. For the first objective, a two-step critical appraisal used clinical criteria (from qualitative studies on barriers to implement routine measures) and psychometric criteria (from Brink and Louw critical appraisal tool) to determine which observation methods could be recommended for clinical practice. For the second objective, we extracted PB found in the literature to list potential PB that patients could exhibit, and clinicians could observe.

Results

From the 3362 retrieved studies, 47 met the inclusion criteria for the first objective. The clinical criteria allowed us to select three observation methods. After the psychometric step, two observation methods were retained and recommended for clinical practice: the Behavioral Avoidance Test-Back Pain (BAT-Back) and the Pain Behaviour Scale (PaBS). For the second objective, 107 studies met the inclusion criteria. The extraction of the PB allowed us to list a large range of PB and classify the data in 7 categories of PB.

Conclusion

Our results allowed us to recommend two observation methods for clinical practice. However, these methods have limitations and are validated only in chronic low back pain populations. With the extraction of PB presented in the literature, we contribute to better prepare clinicians to recognize PB in all patients who are experiencing pain.

Optimizing Long-term Outcomes of Exposure for Chronic Primary Pain from the Lens of Learning Theory

Exposure in vivo is a theory-driven and widely used treatment to tackle functional disability in people with chronic primary pain. Exposure is quite effective; yet, in line with exposure outcomes for anxiety disorders, a number of patients may not profit from it, or relapse. In this focus article, we critically reflect on the current exposure protocols in chronic primary pain, and provide recommendations on how to optimize them. We propose several adaptations that are expected to strengthen inhibitory learning and/or retrieval of the extinction memory, thus likely decreasing relapse. We summarize the limited, but emerging experimental data in the pain domain, and draw parallels with experimental evidence in the anxiety literature. Our reflections and suggestions pertain to the use of the fear hierarchy, reassurance, positive psychology interventions, exposure with a range of stimuli and within different contexts, and the use of safety behaviors during treatment, as well as associating the fear-inducing stimuli with novel outcomes. In addition, we reflect on the importance of specifically tackling (the return of) pain-related avoidance behavior with techniques such as disentangling fear from avoidance and reinforcing approach behaviors. Finally, we discuss challenges in the clinical application of exposure to improve functioning in chronic primary pain and possible avenues for future research. Perspectives: Inspired by recent advances in learning theory and its applications on the treatment of anxiety disorders, we reflect on the delivery of exposure treatment for chronic primary pain and propose strategies to improve its long-term outcomes.

Avoidance behaviour performed in the context of a novel, ambiguous movement increases threat and pain-related fear

ABSTRACT

The fear-avoidance model of chronic pain predicts that catastrophic (mis)interpretation of pain elicits pain-related fear that in turn may spur avoidance behaviour leading to chronic pain disability. Here, we investigated whether performing a movement to avoid a painful stimulus in the context of a novel movement increases threat and pain-related fear towards this novel movement and whether avoidance behaviour persisted when given the choice between performing the acquired movement to avoid a painful stimulus or an alternative, novel movement. Applying a robotic arm-reaching task, participants could choose between 2 movements to reach a target location: a short, but painful movement trajectory, or a longer nonpainful movement trajectory. After avoidance acquisition, the option to choose the painful trajectory was removed. The experimental group (N = 50) could choose between the longest trajectory or a novel intermediate trajectory, whereas the control group (N = 50) was allowed to only perform the novel trajectory. In a final test, participants of both groups were allowed to choose any of the 3 trajectories. After acquisition, experimental group participants showed elevated pain expectancy and pain-related fear towards the novel trajectory, compared with the control group. During test, the experimental group participants persisted in performing the longest pain-free (avoidance) trajectory and were less likely to choose the novel trajectory. In addition, these participants maintained higher levels of pain-related fear for the novel trajectory compared with the control group. These findings suggest that avoidance in the context of other neutral activities/movements may lead to the development and maintenance of threat appraisals and irrational fears.

The Perceived Opportunity to Avoid Pain Paradoxically Increases Pain-Related Fear Through Increased Threat Appraisals

BACKGROUND

Although pain-related avoidance is mainly intended to reduce the accompanying anticipatory fear, avoidance behavior may paradoxically increase fear when a previous avoidance response is no longer available, suggesting that there is a bidirectional relationship between pain-related fear and avoidance.

PURPOSE

We hypothesized that avoidance can serve as a source of information that fuels irrational pain-related threat appraisals, which, in turn, increases pain-related fear.

METHODS

Participants (N = 66) were exposed to a painful heat stimulus and randomly assigned to the avoidance or control group. They were instructed to avoid the full heat intensity by pressing a stop button in the presence of a stop cue. Only avoidance group participants received a stop cue and were allowed to press the stop button, while control group participants received the same instructions but never had the opportunity to avoid the full heat intensity. In reality and unknown to participants, the intensity and duration of the heat stimulus was independent of the avoidance response. In the subsequent test phase, the avoidance response was unavailable for both groups. We measured pain-related fear, threat appraisals/harmfulness, and pain intensity.

RESULTS

In line with our expectations, pain-related fear levels were higher when the avoidance response was no longer available compared to those when the avoidance response was available. Increased threat appraisals mediated the relationship between avoidance behavior and increased pain-related fear.

CONCLUSIONS

The perceived opportunity to avoid increased pain-related fear through threat appraisals, suggesting a more complicated relationship between pain-related fear, threat appraisals, and avoidance behavior than the unidirectional relationships proposed in the fear-avoidance model. Clinical implications are discussed.

Patient phenotyping in clinical trials of chronic pain treatments: IMMPACT recommendations

There is tremendous interpatient variability in the response to analgesic therapy (even for efficacious treatments), which can be the source of great frustration in clinical practice. This has led to calls for “precision medicine” or personalized pain therapeutics (ie, empirically based algorithms that determine the optimal treatments, or treatment combinations, for individual patients) that would presumably improve both the clinical care of patients with pain and the success rates for putative analgesic drugs in phase 2 and 3 clinical trials. However, before implementing this approach, the characteristics of individual patients or subgroups of patients that increase or decrease the response to a specific treatment need to be identified. The challenge is to identify the measurable phenotypic characteristics of patients that are most predictive of individual variation in analgesic treatment outcomes, and the measurement tools that are best suited to evaluate these characteristics. In this article, we present evidence on the most promising of these phenotypic characteristics for use in future research, including psychosocial factors, symptom characteristics, sleep patterns, responses to noxious stimulation, endogenous pain-modulatory processes, and response to pharmacologic challenge. We provide evidence-based recommendations for core phenotyping domains and recommend measures of each domain.

Freeze-like responses to pain in humans and its modulation by social context

Background

Maladaptive defensive responses such as excessive avoidance behavior have received increasing attention as a main mechanism for the development and maintenance of chronic pain complaints. However, another defensive response which is commonly studied in animals as a proxy for fear is freezing behavior. No research to date has investigated human freezing behavior in the context of pain. In addition, there is an increasing realization that social context can affect pain-relevant processes such as pain experience and pain behavior but less is known about the effects of social context on defensive responses to pain. Hence, this study investigated freezing behavior and facial pain expression in the context of pain, and their modulation by social context.

Methods

Healthy, pain-free participants (N = 39) stood on a stabilometric force platform in a threatening or safe social context, which was manipulated using angry or happy facial stimuli. In some trials, an auditory cue (conditioned stimulus; CS) predicted the occurrence of painful electrocutaneous stimulus (unconditioned stimulus; pain-US). We assessed body sway (an index of freezing), heart rate, facial pain expression, self-reported pain intensity, unpleasantness, and pain-US expectancy during the CS and the context alone (no CS).

Results

The results were mixed. Neither the anticipation of pain, nor social context affected body sway. Heart rate and painful facial expression were reduced in the threatening social context at high anxiety levels. A threatening social context also elicited higher pain-US expectancy ratings. In sum, a threatening social context increases the expectation of pain, but reduces the facial expression of pain and lowers heart rate in highly anxious individuals.

Emotion regulation as a transdiagnostic factor underlying co-occurring chronic pain and problematic opioid use

Chronic pain is a common and costly condition, and some people with chronic pain engage in problematic opioid use. There is a critical need to identify factors underlying this co-occurrence, so that treatment can be targeted to improve outcomes. We propose that difficulty with emotion regulation (ER) is a transdiagnostic factor that underlies the co-occurrence of chronic pain and problematic opioid use (CP-POU). In this narrative review, we draw from prominent models of ER to summarize the literature characterizing ER in chronic pain and CP-POU. We conclude that chronic pain is associated with various ER difficulties, including emotion identification and the up- and down-regulation of both positive and negative emotion. Little research has examined ER specifically in CP-POU; however, initial evidence suggests CP-POU is characterized by difficulties with ER that are similar to those found in chronic pain more generally. There is great potential to expand the treatment of ER to improve pain-related outcomes in chronic pain and CP-POU. More research is needed, however, to elucidate ER in CP-POU and to determine which types of ER strategies are optimal for different clinical presentations and categories of problematic opioid use. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Which Psychological Factors Are Involved in the Onset and/or Persistence of Musculoskeletal Pain? An Umbrella Review of Systematic Reviews and Meta-Analyses of Prospective Cohort Studies

OBJECTIVE

The objective of this study was to summarize the current status of knowledge about the longitudinal association between vulnerability or protective psychological factors and the onset and/or persistence of musculoskeletal (MSK) pain.

METHODS

PubMed, CINAHL, PsycINFO, PubPsych, Scopus, Web of Science, gray literature, and manual screening of references were searched from inception to June 15, 2019. Systematic reviews with or without meta-analysis that explored the longitudinal association between psychological factors and the onset and/or persistence of MSK pain were identified. The AMSTAR-2 tool was used to assess the risk of bias.

RESULTS

Fifty-nine systematic reviews that included 286 original research studies were included, with a total of 249,657 participants (127,370 with MSK pain and 122,287 without MSK pain at baseline). Overall, our results found that exposure to many psychological vulnerability factors such as depression, anxiety, psychological distress, and fear, among others, may increase the risk of the onset and persistence of MSK pain across time. In addition, our results also showed that a range of psychological factors considered to be "protective" such as self-efficacy beliefs, better mental health, active coping strategies, or favorable expectations of recovery may reduce the risk of the onset and persistence of MSK pain. However, all these systematic reviews were evaluated to have critically low confidence based on the AMSTAR-2 tool, indicating that findings from these reviews may be informative, but should be interpreted with caution.

DISCUSSION

The large number of methodological flaws found across reviews gives rise to a call to action to develop high-quality systematic reviews in this field.

Cross-cultural adaptation and validation of the Behavioral Avoidance Test-Back Pain (BAT-Back) to the Turkish language

OBJECTIVE

Pain-avoidance is considered to be one of the major leading factors to develop a chronic low back pain (CLBP). In this study, we aimed to translate the Behavioral Avoidance Test-Back Pain (BAT-Back) into Turkish and evaluate its psychometric properties in patients with CLBP.

METHODS

115 patients with CLBP filled the provided socio-demographic information form, the "Oswestry Disability Index (ODI)", the "Fear-Avoidance Beliefs Questionnaire (FABQ)", the "Tampa Scale for Kinesiophobia (TSK)", and the "Hospital Anxiety Depression Scale (HADS)". All patients and 40 pain free controls (PFC) were administered the Turkish version (TrBAT-Back) of the "Behavioral Avoidance Test-Back Pain" test. The internal consistency was evaluated with Cronbach's α coefficient. The test-retest reliability was assessed with the intraclass correlation coefficient (ICC). To evaluate the structural validity of TrBAT-Back, its correlation with FABQ, TSK, ODI, and HADS was examined.

RESULTS

The internal consistency of TrBAT-Back was excellent (Cronbach's α = 0.97) and its test-retest reliability was good (ICC = 0.87). Its high correlation with the FABQ-physical activity scores and moderate correlation with the TSK scores supported the structural validity. The TrBAT-Back scores showed a statistically significant moderate correlation with the higher level of pain and disability. Despite the low degree of positive correlation, a high level of anxiety (HADS-anxiety) is potentially associated with avoidance behaviour. CLBP patients and controls differed significantly on TrBAT-Back avoidance scores.

CONCLUSION

We are of the opinion that, compared to the self-report scales, TrBAT-Back will provide more objective data in detecting avoidance behaviour associated with pain in Turkish speaking patients with CLBP.

Avoidance Behavioral Difference in Acquisition and Extinction of Pain-Related Fear

Fear of movement-related pain leads to two types of avoidance behavior: excessive avoidance and pain-inhibited movement. Excessive avoidance is an absence of movement by fear, and pain-inhibited movements involve a change in motor behavior for the purpose of protecting the painful part. Here, we sought to clarify the acquisition process and adaptation of fear for each avoidance behavior. Thirty-one female and 13 male (age 20.9 ± 2.1 years) subjects could decide persistent behaviors: approach with an intense pain stimulus, pain-inhibited movement with weak pain stimulus, or excessive avoidance with no pain in acquisition and test phases. In the subsequent extinction phase, the pain stimulus was omitted. Subjects were divided into an approach group (n = 24), a pain-inhibited movement group (n = 10), and an excessive avoidance group (n = 10) by cluster analysis. The response latencies in approach and pain-inhibited movement groups were not affected by conditioned pain. The subjects in the excessive avoidance group exhibited delayed response latencies, and their high-fear responses remained in the acquisition, test, and extinction phases. In addition, the excessive avoidance group showed high harm avoidance and high trait anxiety. This study demonstrated that differences in pain-related avoidance behaviors are affected by psychological traits. Pain-related excessive avoidance behavior indicated a maladaptive fear, but pain-inhibited movement did not.

The Fear of Pain Questionnaire: Factor structure, validity and reliability of the Italian translation

Background

The Fear of Pain Questionnaire-III (FPQ-III) is a self-report instrument developed to assess fear of different stimuli usually causing pain. The present study aimed to construct an Italian version of the FPQ-III and examine its psychometric properties in a heterogeneous sample of Italian healthy individuals.

Methods

The questionnaire was translated following the forward-backward method and completed by 511 Italian adults who met the inclusion criteria. Within 2 months of the first assessment, a subgroup of participants (n = 164) was re-tested. The factorial structure of the FPQ-III was assessed by confirmatory factor analysis (CFA). To better comprehend the FPQ-III’s factorial structure, a CFA was also performed for each of the two reduced versions of the FPQ-III, namely the FPQ-Short Form and the FPQ-9. Divergent validity, test-retest reliability, and gender/age measurement invariance were also evaluated.

Results

The results of the CFA revealed that the original three-factor model poorly fitted the data, but it became satisfactory after allowing correlated error terms. Concerning divergent validity, correlations between FPQ-III scores and pain intensity, depression, and anxiety were found to be positive but weak in magnitude (< .20). FPQ-III subscales and total scores showed good internal consistency and time reliability. Finally, scalar invariance was only partially obtained, whereas all the other types of invariance were fully respected both for gender and age.

Conclusions

The current findings indicate that the Italian version of the FPQ-III provides valid and reliable scores for the assessment of fear of pain in the Italian population.

Evaluating psychosocial contributions to chronic pain outcomes

The biopsychosocial model of pain dominates the scientific community's understanding of chronic pain. Indeed, the biopsychosocial approach describes pain and disability as a multidimensional, dynamic integration among physiological, psychological, and social factors that reciprocally influence one another. In this article, we review two categories of studies that evaluate the contributions of psychosocial factors to the experience of chronic pain. First, we consider general psychosocial variables including distress, trauma, and interpersonal factors. Additionally, we discuss pain-specific psychosocial variables including catastrophizing, expectations, and pain-related coping. Together, we present a diverse array of psychological, social, and contextual factors and highlight the need to consider their roles in the development, maintenance, and treatment of chronic pain conditions.

Patient perspectives on improving osteoarthritis management in urban and rural communities

Introduction

Although there is no cure for osteoarthritis (OA), there are lifestyle modifications that can mitigate symptoms such as pain, and improve management of the disease. This information is not always translated to community-dwelling seniors. Individuals in rural areas often face additional challenges due to geographic isolation and decreased access to community services.

Methods

We used qualitative research methodology (hermeneutic phenomenology) to better understand the lived experiences of urban and rural community-dwelling seniors diagnosed with OA. We explored their sources of information about OA, how they manage their OA pain, and how OA management could be improved in the community. Purposeful sampling was used to recruit 20 information-rich participants (11 urban, 9 rural) in Ontario, Canada. All participants were aged >65 and diagnosed with OA. Semi-structured interviews were conducted, audio recorded, and transcribed verbatim. NVivo 11 Pro qualitative software was used to code transcripts.

Results

Thematic analysis revealed 9 key themes where 8 were common to urban and rural participants, and 1 was unique to rural participants. Most significant among the common themes was the description of the social network as a source of OA information, the trial-and-error approach used for OA management, and the individual contextualization of OA management. Our results suggest that there are several common experiences among urban- and rural-dwelling seniors living with OA, including the desire for support over time, but also a unique experience to rural-dwelling seniors, namely lack of access to local care.

Conclusion

These findings can be used to improve translation of OA information in both urban and rural communities in Canada, highlighting that common strategies may be effective in different contexts for this disease.

Barriers and facilitators of physical activity in knee and hip osteoarthritis: a systematic review of qualitative evidence

Physical activity (PA), including engagement in structured exercise, has a key role in the management of hip and knee osteoarthritis (OA). However, maintaining a physically active lifestyle is a challenge for people with OA. PA determinants in this population need to be understood better so that they can be optimised by public health or healthcare interventions and social policy changes.

OBJECTIVES

The primary aim of this study is to conduct a systematic review of the existing qualitative evidence on barriers and facilitators of PA for patients with hip or knee OA. Secondary objective is to explore differences in barriers and facilitators between (1) lifestyle PA and exercise and (2) PA uptake and maintenance.

METHODS

Medline, Embase, Web of Science, Cumulative Index to Nursing and Allied Health Literature, SPORTDiscus, Scopus, Grey literature and qualitative journals were searched. Critical Appraisal Skills Programme-Qualitative checklist and Lincoln and Guba's criteria were used for quality appraisal. Thematic synthesis was applied.

FINDINGS

Ten studies were included, seven focusing on exercise regimes, three on overall PA. The findings showed a good fit with the biopsychosocial model of health. Aiming at symptom relief and mobility, positive exercise experiences and beliefs, knowledge, a 'keep going' attitude, adjusting and prioritising PA, having healthcare professionals' and social support emerged as PA facilitators. Pain and physical limitations; non-positive PA experiences, beliefs and information; OA-related distress; a resigned attitude; lack of motivation, behavioural regulation, professional support and negative social comparison with coexercisers were PA barriers. All themes were supported by high and medium quality studies. Paucity of data did not allow for the secondary objectives to be explored.

CONCLUSION

Our findings reveal a complex interplay among physical, personal including psychological and social-environmental factors corresponding to the facilitation and hindrance of PA, particularly exercise, engagement. Further research on the efficacy of individualised patient education, psychological interventions or social policy change to promote exercise engagement and lifestyle PA in individuals with lower limb OA is required.

TRIAL REGISTRATION NUMBER

CRD42016030024.

Patient phenotyping in clinical trials of chronic pain treatments: IMMPACT recommendations

There is tremendous interpatient variability in the response to analgesic therapy (even for efficacious treatments), which can be the source of great frustration in clinical practice. This has led to calls for "precision medicine" or personalized pain therapeutics (ie, empirically based algorithms that determine the optimal treatments, or treatment combinations, for individual patients) that would presumably improve both the clinical care of patients with pain and the success rates for putative analgesic drugs in phase 2 and 3 clinical trials. However, before implementing this approach, the characteristics of individual patients or subgroups of patients that increase or decrease the response to a specific treatment need to be identified. The challenge is to identify the measurable phenotypic characteristics of patients that are most predictive of individual variation in analgesic treatment outcomes, and the measurement tools that are best suited to evaluate these characteristics. In this article, we present evidence on the most promising of these phenotypic characteristics for use in future research, including psychosocial factors, symptom characteristics, sleep patterns, responses to noxious stimulation, endogenous pain-modulatory processes, and response to pharmacologic challenge. We provide evidence-based recommendations for core phenotyping domains and recommend measures of each domain.