Human Studies

Although support provision by a partner is an important resource for individuals with chronic pain (ICPs), it poses a challenge for partners because it competes with other important personal goals of partners. The current study examined the impact of experimentally induced goal conflict in partners on their motives for helping, quality of provided help, and on partners' and ICPs' affect. Sixty-eight couples, with at least one person having chronic pain, performed two series of household activities, with partners either asked to be simply available for help (i.e., control condition) or to additionally work on a puzzle task (i.e., goal conflict condition). Couples reported on interpersonal (e.g., helping motives) and intrapersonal (e.g., affect) outcomes. In addition, quality of partners' helping behavior and ICPs' pain behavior were videotaped and coded afterwards. In the goal conflict condition, ICPs were less satisfied with the received help and they experienced more pain. Also, the quality of the provided help was lower and partners experienced less positive and more negative affect. Addressing partners' goal conflict in clinical practice may help to avoid its negative impact on both ICPs and partners. Perspective: This article provides a compelling argument to include partners in chronic pain treatment by demonstrating the detrimental effects of partners' experienced conflicts in goals upon the quality of help they provide, partners' affective functioning and ICPs' pain-related outcomes.

In exposure for chronic pain, avoidance is often forbidden (extinction with response prevention; RPE) to prevent misattributions of safety. Although exposure is an effective treatment, relapse is common. Little is known about the underlying mechanisms of return of pain-related avoidance. We hypothesized that pain-related avoidance would recover when becoming available again after RPE and after unexpected pain episodes ("reinstatement"), especially when restricting avoidance during RPE (compared to instructing not to use it). In an operant pain-related avoidance conditioning paradigm, healthy volunteers used a robotic arm to perform various arm reaching movements differing in pain-effort trade-off. During acquisition, participants learned to avoid pain by performing more effortful movements. During RPE they only performed the formerly pain-associated movement under extinction, and were either forbidden (Restricted group) or merely instructed (Instructed group) not to perform other movements. One day later, we tested spontaneous recovery and reinstatement of pain-related fear and avoidance with availability of all movements. Results showed that pain-related fear and avoidance re-emerge after RPE, though not to pre-treatment levels. The reinstatement manipulation had no additional effect. No group differences were observed. We discuss findings in the context of learning processes in (chronic) pain disability and relapse prevention in chronic pain treatment. Perspective: Using experimental models of relapse, we investigated the return of pain-related avoidance behaviour after extinction with response prevention. Findings are potentially informative for clinicians performing exposure treatment with chronic pain patients.

Acute and chronic pain delay recovery and impair outcomes after major pediatric surgery. Understanding unique risk factors for acute and chronic pain is critical to developing effective treatments for youth at risk. We aimed to identify adolescent and family psychosocial predictors of acute and chronic postsurgical pain following major surgery in adolescents. Participants included 119 youth age 10-18 years (M=14.9;78.2% white) undergoing major musculoskeletal surgery and their parents. Participants completed pre-surgery baseline questionnaires, with youth reporting on baseline pain, anxiety, depression, insomnia and sleep quality, and parents reporting on parental catastrophizing and family functioning. At baseline, 2-weeks, and 4-months post-surgery, youth completed 7-days of daily pain diaries and reported on health-related quality of life. Sequential logistic regression models examined pre-surgery predictors of acute and chronic postsurgical pain, defined as significant pain with impairment in health-related quality of life. Acute pain was experienced by 27.2% of youth at 2-weeks, while 19.8% of youth met criteria for chronic pain at 4-months. Baseline pain predicted acute pain (OR=1.96; 95%CI=1.32-2.90), while depressive symptoms (OR=1.22; 95%CI=1.01-1.47) and sleep quality (OR=0.26; 95%CI=0.08-0.83) predicted chronic pain. Tailored interventions need to be developed and incorporated into perioperative care to address risk factors for acute and chronic pain. Perspective: Longitudinal results demonstrate adolescents' pre-surgery pain severity predicts acute postsurgical pain, while depressive symptoms and poor sleep quality predict chronic postsurgical pain. Tailored interventions should address separate risk factors for acute and chronic pain after adolescent surgery.

Avoidance behavior is protective, yet in the absence of genuine bodily threat, it may become disabling. Therefore, we investigated whether avoidance generalizes to novel safe contexts based on the similarity with the acquisition context. Healthy participants performed arm movements using a robotic arm to reach a target. Three trajectories (T1-3) led to the target. During acquisition, a painful stimulus could be partly/completely prevented by performing more effortful trajectories (i.e. longer and more force needed), T2/T3, in the pain-avoidance context (e.g. black background); in the yoked context (e.g. white background), the same reinforcement schedule was applied irrespective of the chosen trajectories. Generalization of avoidance was tested in two novel contexts (e.g. shades of grey backgrounds). We assessed self-reported pain-expectancy and pain-related fear for all trajectories, and avoidance behavior (i.e. maximal deviation from T1). Results confirm that fear and expectancy ratings reflect the response-outcome contingencies and differential learning selectively generalized to the novel context resembling the original pain-avoidance context. Furthermore, a linear trend in avoidance behavior across contexts emerged, which is indicative of a generalization gradient. Participants avoided more in the context resembling the original pain-avoidance context than in the one resembling the yoked context, but this effect was not statistically significant. PERSPECTIVE: We demonstrated acquisition of pain-related avoidance behavior in a within-subjects design, showing modulation of pain-related fear and pain-expectancy by context and providing limited evidence that avoidance selectively generalizes to novel, similar contexts. These results provide insight regarding the underlying mechanisms of the spreading of protective behavior in chronic pain patients.

Pain catastrophizing (PC) has been recognized as an important and consistent psychosocial predictor of nearly every key pain-related outcome. The purpose of this study was to develop a new measure of PC using modern psychometric methodology. People with chronic pain (N=795) responded to thirty items. Data were analyzed using Item Response Theory (IRT), including assessment of differential item functioning (DIF) and reliability. Sensitivity to change and validity were examined using data collected from patients undergoing spinal fusion surgery (n=184) and participating in an ongoing longitudinal aging with a disability survey study (n=1388). The final 24-item bank had no items with significant local dependence, misfit, or DIF. Results provided strong evidence of reliability and validity. Six- and 2-item short forms were developed for use when computer adaptive testing (CAT) is not feasible or desirable. The item bank was named the University of Washington Concerns About Pain (CAP) scale because the term "catastrophizing" was considered stigmatizing by people with chronic pain. Guidance for score interpretation was developed with extensive feedback from individuals with chronic pain. The CAP item bank, short forms, and user manuals are free and publicly available to all users and can be accessed online at https://uwcorr.washington.edu/measures/. PERSPECTIVE: This article presents the development of the University of Washington Concerns About Pain scale, the first IRT-based item bank of pain catastrophizing. The measure is intended for clinicians interested in improving outcomes of patients with chronic pain and for researchers who study impact of and treatment interventions aimed at reducing pain catastrophizing.

Pain is an unfortunate consequence of many medical procedures, which in some patients becomes chronic and debilitating. Among the factors affecting medical pain, clinician-patient (C-P) similarity and nonverbal communication are particularly important for pain diagnosis and treatment. Participants (N=66) were randomly assigned to the clinician and patient roles and were grouped into C-P dyads. Clinicians administered painful stimuli to patients as an analogue of a painful medical procedure. We manipulated the perceived C-P similarity of each dyad using groups ostensibly based on shared beliefs and values, and each patient was tested twice: Once with a same group clinician (concordant, CC) and once with a clinician from the other group (discordant, DC). Movement synchrony was calculated as a marker of nonverbal communication. We tested whether movement synchrony mediated the effects of group concordance on patients' pain and trust in the clinician. Movement synchrony was higher in CC than DC dyads. Higher movement synchrony predicted reduced pain and increased trust in the clinician. Movement synchrony also formally mediated the group concordance effects on pain and trust. These findings increase our understanding of the role of nonverbal C-P communication on pain and related outcomes and suggest that interpersonal synchrony may be associated with better patient outcomes, independent of the specific treatment provided. Perspective This article demonstrates that movement synchrony in clinician-patient interactions is an unobtrusive measure related to their relationship quality, trust towards the clinician, and pain. These findings suggest that interpersonal synchrony may be associated with better patient outcomes, independent of the specific treatment provided.