Developing a core outcome domain set to assessing effectiveness of interdisciplinary multimodal pain therapy: the VAPAIN consensus statement on core outcome domains

Is personalization of psychological pain treatments necessary? Evidence from a Bayesian variance ratio meta-analysis

ABSTRACT

This is the first study to empirically determine the potential for data-driven personalization in the context of chronic primary pain (CPP). Effect sizes of psychological treatments for individuals with CPP are small to moderate on average. Aiming for better treatment outcomes for the individual patient, the call to personalize CPP treatment increased over time. However, empirical evidence that personalization of psychological treatments can optimize treatment outcomes in CPP is needed. This study seeks to estimate heterogeneity of treatment effect for cognitive behavioral therapy (CBT) as the psychological treatment approach for CPP with the greatest evidence base. For this purpose, a Bayesian variance ratio meta-regression is conducted using updated data from 2 recently published meta-analyses with randomized controlled trials comparing CBT delivered face-to-face to treatment-as-usual or waiting list controls. Heterogeneity in patients with CPP would be reflected by a larger overall variance in the post-treatment score compared with the control group. We found first evidence for an individual treatment effect in CBT compared with the control group. The estimate for the intercept was 0.06, indicating a 6% higher variance of end point values in the intervention groups. However, this result warrants careful consideration. Further research is needed to shed light on the heterogeneity of psychological treatment studies and thus to uncover the full potential of data-driven personalized psychotherapy for patients with CPP.A Bayesian variance ratio meta-regression indicates empirical evidence that data-driven personalized psychotherapy for patients with chronic primary pain could increase effects of cognitive behavioral therapy.

Prediction models for treatment success after an interdisciplinary multimodal pain treatment program

Chronic musculoskeletal pain (CMP) poses a widespread health and socioeconomic problem, being the most prevalent chronic pain condition. Interdisciplinary multimodal pain treatment (IMPT) is considered the gold standard, offering cost-effective long-term care. Unfortunately, only a subset of patients experiences clinically relevant improvements in pain, fatigue, and disability post-IMPT. Establishing a prediction model encompassing various outcome measures could enhance rehabilitation and personalized healthcare. Thus, the aim was to develop and validate a prediction model for IMPT success in patients with CMP. A prospective cohort study within routine care was performed, including patients with CMP undergoing a 10-week IMPT. Success across four outcome measures was determined: patients' recovery perspective, quality of life (physical and mental), and disability. Sixty-five demographic and candidate predictors (mainly patient reported outcome measures) were examined. Finally, 2309 patients participated, with IMPT success rates ranging from 30% to 57%. Four models incorporating 33 predictors were developed, with treatment control being the sole consistent predictor across all models. Additionally, predictors effects varied in direction in the models. All models demonstrated strong calibration, fair to good discrimination, and were internally validated (optimism-corrected AUC range 0.69-0.80). Our findings show that treatment success can be predicted using standardized patient-reported measures, exhibiting strong discriminatory power. However, predictors vary depending on the outcome, underscoring the importance of selecting the appropriate measure upfront. Clinically, these results suggest potential for patient-centered care and may contribute to the development of a scientifically sound decision tool.

German language adaptation of the Cluster Headache Quality of Life Scale (CH-QoL)

BACKGROUND

Cluster headache (CH) can lead to high disability and reduced quality of life (QoL). QoL should be assessed as an important outcome both in research and in clinical care. The 28-item Cluster Headache Quality of Life Scale (CH-QoL) is a valid self-report questionnaire to assess disease-specific QoL. A German version is lacking. This study aims to develop a German-language version and to determine its psychometric properties.

METHODS

The CH-QoL was translated into German by two headache experts and blindly back-translated by two professional translators. Additionally, the CH-QoL was tested for comprehensibility by nine persons with CH. In this multi-stage process, linguistic discrepancies were repeatedly discussed in an expert panel and appropriate modifications were conducted to optimize the translation. A cross-sectional online survey, comprising the CH-QoL and further self-report questionnaires such as the Cluster Headache Scales (CHS), yielded a sample of N = 106 persons with CH (53.8% female, M = 45.5 [SD = 11.8] years, 48.1% episodic CH, 51.9% chronic CH, 79.2% currently having recurring CH attacks).

RESULTS

Exploratory factor analysis revealed two clearly interpretable factors ("restriction of activities of daily living", and "impact on mood and interpersonal relationships"), which is in discrepancy to the four factors of the original English version. The model fit was good, with χ2(323) = 590.74, p < .001, RMSEA = 0.088, SRMR = 0.053, TLI = 0.857. Reliability was very good (McDonald's omega ω = 0.97, Subscale/Factor 1: ω = 0.96, Subscale/Factor 2: ω = 0.92). Correlational analyses (correlations with related questionnaires as well as with clinical parameters) confirmed convergent validity.

CONCLUSIONS

Since the German version of the CH-QoL has very good psychometric properties, it is suitable for the assessment of disease-specific QoL in people with CH in German-speaking countries.

TRIAL REGISTRATION

This study is registered with the German Clinical Trials Register (DRKS-ID: DRKS00028475, registration date 03 March 2022).

Improving neuropathic pain treatment - by rigorous stratification from bench to bedside

Chronic pain is a constantly recurring and persistent illness, presenting a formidable healthcare challenge for patients and physicians alike. Current first-line analgesics offer only low-modest efficacy when averaged across populations, further contributing to this debilitating disease burden. Moreover, many recent trials for novel analgesics have not met primary efficacy endpoints, which is particularly striking considering the pharmacological advances have provided a range of highly relevant new drug targets. Heterogeneity within chronic pain cohorts is increasingly understood to play a critical role in these failures of treatment and drug discovery, with some patients deriving substantial benefits from a given intervention while it has little-to-no effect on others. As such, current treatment failures may not result from a true lack of efficacy, but rather a failure to target individuals whose pain is driven by mechanisms which it therapeutically modulates. This necessitates a move towards phenotypical stratification of patients to delineate responders and non-responders in a mechanistically driven manner. In this article, we outline a bench-to-bedside roadmap for this transition to mechanistically informed personalised pain medicine. We emphasise how the successful identification of novel analgesics is dependent on rigorous experimental design as well as the validity of models and translatability of outcome measures between the animal model and patients. Subsequently, we discuss general and specific aspects of human trial design to address heterogeneity in patient populations to increase the chance of identifying effective analgesics. Finally, we show how stratification approaches can be brought into clinical routine to the benefit of patients.

Measurement Error, Minimal Detectable Change, and Minimal Clinically Important Difference of the Short Form-36 Health Survey, Hospital Anxiety and Depression Scale, and Pain Numeric Rating Scale in Patients With Chronic Pain

In both pain research and clinical practice, patient-reported outcome measures are used to assess dimensions of health. Interpreting these instruments requires understanding their measurement error and what magnitude of change has subjective importance for patients. This study estimated the standard error of measurement, 1-year minimal detectable change, and 1-year minimal clinically important difference (MCID) for the Short Form-36 Health Survey physical component summary and mental component summary, the Hospital Anxiety and Depression Scale subscales for anxiety symptoms and depression symptoms, and the numeric rating scale for past-week average pain intensity. MCIDs for these instruments have not previously been estimated in a large sample of chronic pain patients participating in interdisciplinary pain rehabilitation. Data were drawn from the Swedish Quality Registry for Pain Rehabilitation (n = 8,854 patients). MCID was estimated as average change and change difference based on 3 different anchors. MCID estimates were 2.62 to 4.69 for Short Form-36 Health Survey physical component summary, 4.46 to 6.79 for Short Form-36 Health Survey mental component summary, .895 to 1.48 for numeric rating scale, 1.17 to 2.13 for anxiety symptoms in the Hospital Anxiety and Depression Scale, and 1.48 to 2.54 for depression symptoms in the Hospital Anxiety and Depression Scale. The common assumption of an identical standard error of measurement for pre- and post-treatment measurements was not always applicable. When estimating MCID, researchers should select an estimation method and anchor aligned with the study's context and objectives. PERSPECTIVE: This article presents estimates of MCID and minimal detectable change for several commonly used patient-reported outcome measures among patients with chronic pain. These estimates can help clinicians and researchers to determine when a measured health improvement is subjectively important to the patient and greater than measurement error.

Prognostic subgroups of chronic pain patients using latent variable mixture modeling within a supervised machine learning framework

The present study combined a supervised machine learning framework with an unsupervised method, finite mixture modeling, to identify prognostically meaningful subgroups of diverse chronic pain patients undergoing interdisciplinary treatment. Questionnaire data collected at pre-treatment and 1-year follow up from 11,995 patients from the Swedish Quality Registry for Pain Rehabilitation were used. Indicators measuring pain characteristics, psychological aspects, and social functioning and general health status were used to form subgroups, and pain interference at follow-up was used for the selection and the performance evaluation of models. A nested cross-validation procedure was used for determining the number of classes (inner cross-validation) and the prediction accuracy of the selected model among unseen cases (outer cross-validation). A four-class solution was identified as the optimal model. Identified subgroups were separable on indicators, predictive of long-term outcomes, and related to background characteristics. Results are discussed in relation to previous clustering attempts of patients with diverse chronic pain conditions. Our analytical approach, as the first to combine mixture modeling with supervised, targeted learning, provides a promising framework that can be further extended and optimized for improving accurate prognosis in pain treatment and identifying clinically meaningful subgroups among chronic pain patients.

Empowering patients with persistent pain: The potential of cognitive functional therapy in interdisciplinary care: A single-case experimental design

INTRODUCTION AND PURPOSE

Persistent musculoskeletal pain (PMP) is multifactorial and causes both societal and financial burdens. Integration of multifactorial management in patients with PMP remains challenging. A single-case experimental design was performed on three patients suffering from high impact PMP (lumbar spine, shoulder and knee) to i) assess the potential for Cognitive Functional Therapy (CFT) in interdisciplinary care, ii) describe in detail the clinical journey patients experienced during the intervention, and iii) evaluate the changes and associations in relation to the outcome measures of pain, disability, maladaptive movement behavior, subjective overall improvement, health related quality of life and work status. These were monitored over one year, at the end of each of the six intervention modules.

RESULTS

After introducing the intervention systematic changes were seen, with medium to large changes (Non-overlap of All Pairs 0.67-1) for all outcome measures. Associations between changes of the outcome measures were large (r ≥ 0.50) and changes occurred concurrently. Minimally clinically important difference thresholds were exceeded for all outcome measures and two patients achieved relevant improvements related to work reintegration.

DISCUSSION

The positive results of this study are comparable with recent CFT studies. However, the difference regarding the number of sessions and duration of the intervention is evident. The length of the intervention in this study seemed to enable continuous significant improvements up until 12 months post onset and follow-up.

CONCLUSION

CFT in interdisciplinary care was effective for all measures. The detailed descriptions of the clinical processes aim to improve clinical care.

How Treatment Motivation Predicts Favorable Outcomes in Interdisciplinary Multimodal Pain Treatment Among Patients with Chronic Primary Pain

As motivation for psychological treatment at intake has been shown to predict favorable outcomes after an inpatient stay, this study aimed to further characterize the different components of psychological treatment motivation that predict favorable treatment outcomes. 294 inpatients with chronic primary pain participating in an interdisciplinary multimodal pain treatment in a tertiary psychosomatic university clinic completed a battery of psychological questionnaires at intake and discharge. Treatment motivation was assessed at intake using the scales of the FPTM-23 questionnaire, while pain intensity, pain interference, anxiety, and depression were assessed both at intake and discharge. After treatment, pain intensity, pain interference, anxiety, and depression were significantly reduced. While higher levels on the FPTM-23 scale of suffering predicted smaller decreases in anxiety after treatment, higher scores on the scale of hope, i.e., lower levels of hopelessness, predicted lower levels of pain interference, anxiety, and depression after treatment. None of the scales of treatment motivation predicted pain intensity levels after treatment. Above and beyond providing symptom relief, reducing hopelessness and fostering hope regarding the treatment process and outcome might help clinicians treat patients with chronic primary pain more effectively.

Interdisciplinary pain rehabilitation for patients with Ehlers-Danlos syndrome and hypermobility spectrum disorders

OBJECTIVE

Chronic pain is a common manifestation of Ehlers-Danlos syndrome and hypermobility spectrum disorders; thus it is often suggested that patients undergo generic interdisciplinary pain rehabilitation, despite there being little evidence to support this decision. The aim of this study is to examine the effectiveness of standard rehabilitation programmes for chronic pain on patients with Ehlers-Danlos syndrome and hypermobility spectrum disorders, compared with patients with other chronic pain disorders.

SUBJECTS

Data, collected between 2008 and 2016, were extracted from a Swedish national registry. The patient data comprised of 406 cases with Ehlers-Danlos syndrome or hypermobility spectrum disorders, 784 cases with a whiplash-related diagnosis, 3713 cases with diagnoses relating to spinal pain, and 2880 cases of fibromyalgia.

METHODS

The differences between groups on key outcome measures from pre- to 1-year follow-up after interdisciplinary pain rehabilitation were analysed using linear mixed effects models. Sensitivity analysis in the form of pattern-mixture modelling was conducted to discern the impact of missing data.

RESULTS

No significant differences were found in improvements from pre- to 1-year follow-up for patients with Ehlers-Danlos syndrome or hypermobility spectrum disorder compared with other diagnostic groups regarding measures of health-related quality of life, mental health, or fatigue. At follow-up, differences in pain interference (d = -0.34 (95% confidence interval [95% CI] -0.5 to -0.18)), average pain (d = 0.22 (95% CI 0.11-0.62)) and physical functioning (d = 2.19 (95% CI 1.61-2.77)) were detected for the group with spinal-related diagnoses in relation to those with EDS/HSD, largely due to pre-treatment group differences. Sensitivity analysis found little evidence for missing data influencing the results.

CONCLUSION

This study suggests that patients with Ehlers-Danlos syndrome/hypermobility spectrum disorders may benefit from inclusion in an interdisciplinary pain rehabilitation programme.

Acceptance and Fear-Avoidance Mediate Outcomes of Interdisciplinary Pain Rehabilitation Programs at 12-Month Follow-Up: A Clinical Registry-Based Longitudinal Cohort Study from the Swedish Quality Registry for Pain Rehabilitation (SQRP)

Background

Factors that influence outcomes of interdisciplinary pain rehabilitation programs (IPRP) are poorly known. It is unclear how outcomes are influenced by pain intensity, psychological distress, and coping strategies.

Aim

This clinical registry-based longitudinal cohort study has three aims: 1) to determine the relative importance of pain intensity, psychological distress, acceptance, and fear-avoidance for changes in three outcomes of IPRP at 12-month follow-up; 2) to investigate whether the effects of pain intensity and psychological distress on the three outcomes are mediated via acceptance and fear-avoidance; and 3) to determine whether sex is a moderator.

Methods

This study uses Patient-Reported Outcome Measures (PROMs) from specialist units reporting data (2008-2016) to the Swedish Quality Registry for Pain Rehabilitation (SQRP). Adult chronic pain patients (N = 1991) answered the PROMs (background, pain, psychological distress, coping, participation, and health-related quality of life (HRQoL)). Partial Least Squares Structural Equation Modelling (PLS-SEM) was used to explore the aims.

Results

Changes in acceptance (β:0.424-0.553; all P<0.001) were the strongest predictor of the three outcomes (changes in life control, interference, and HRQoL) at 12-month follow-up. The next strongest predictor was baseline acceptance (β: 0.177-0.233; all P<0.001) and changes in fear-avoidance (β: -0.152- -0.186; all P<0.001). Baseline pain intensity and psychological distress showed weak positive associations. Their effects on the three outcomes were mediated via acceptance aspects. Sex was not a moderator.

Discussion and Conclusion

Acceptance aspects (baseline and changes) were important predictors of IPRP outcomes. Changes in fear-avoidance were also important although to a lesser degree. Some of the effects of pain intensity and psychological distress on outcomes were mediated via acceptance at baseline. Future PLS-SEM analysis of real-world IPRP should include more potential mediators (eg, catastrophizing and more facets of psychological flexibility and fear-avoidance) and the components of IPRP.

Changes in pain, daily occupations, lifestyle, and health following an occupational therapy lifestyle intervention: a secondary analysis from a feasibility study in patients with chronic high-impact pain

OBJECTIVES

This study explored changes in pain-related parameters, occupational function, occupational balance, lifestyle factors, and self-perceived health status in adults with chronic high-impact pain participating in an occupational therapy lifestyle intervention.

METHODS

This one-group longitudinal feasibility study was performed in three continuous feasibility rounds. The occupational therapists-led intervention targeted meaningful occupations, regular physical activity, and a healthy diet. The intervention contained individual and group sessions and was added to the standard multidisciplinary chronic pain treatment. Outpatients (n=40, 85 % females, 46.6 ± 10.9 years old) participated in the study between April 2019 and December 2021. The analysis includes data for 31 participants. Analysis of pre-post changes assessed after each feasibility round were performed for the outcomes: pain intensity, pain sensitivity and pain modulation (pressure pain threshold and tolerance, temporal summation of pain and conditioned pain modulation), pain self-efficacy, pain catastrophizing, motor and process skills, occupational balance, daily wake-time movement, daily walking steps, body mass index, waist circumference, blood pressure, and self-perceived health status.

RESULTS

Improvements in motor skills (assessment of motor and process skills score=0.20 (1.37; 1.57), 95 % CI 0.01; 0.38) and temporal summation of pain (-1.19 (2.86; -1.67), 95 % CI -2.16; -0.22), but a decrease in pain tolerance (-7.110 (54.42; 47.32), 95 % CI -13.99; -0.22) were observed. Correlation analysis suggested moderate-to-very strong statistically significant relationships in several outcomes related to pain, health, pain coping, occupational balance, occupational functioning, body anthropometrics, and pain sensitivity.

CONCLUSIONS

This study suggested that the lifestyle intervention would benefit motor skills while effects on other outcomes were unclear in adults with chronic pain. To confirm the findings, a randomized trial evaluating effectiveness is needed. Ethical committee number: SJ-307 Reg. Clinicaltrials.gov: NCT03903900.

An Exploration of Physical Therapy Outcomes and Psychometric Properties of the Patient-Specific Functional Scale After an Interdisciplinary Pain Management Program

OBJECTIVES

The Patient-Specific Functional Scale (PSFS) has been used to assess physical functioning in various chronic pain populations. There is a lack of evidence for its use with diverse pain populations who have high-impact chronic pain (HICP). The primary aim of this study was to assess the psychometric properties of the PSFS with a heterogeneous sample of patients with HICP.

MATERIALS AND METHODS

A retrospective observational study of prospective functional outcomes collected before and after participation in an intensive pain management program: PSFS, Disabilities of the Arm, Shoulder, and Hand, Lower Extremity Functional Scale, Neck Disability Index, Oswestry Disability Index, multidimensional patient impression of change, pain intensity, pain limitation, and fear-avoidance from the charts of 509 intensive pain management program completers. The reliability, validity, and responsiveness of the PSFS were analyzed using Cronbach α, Pearson correlations, and receiver operating characteristics.

RESULTS

Statistically significant improvements were found for all outcomes after program participation (all P < 0.0001). Correlations of the PSFS with similar outcomes (convergent validity) were lower than expected ( r = 0.16 to 0.33). A low correlation ( r = -0.12) with an unrelated measure, fear avoidance, supported divergent validity. PSFS change score correlations with similar outcome measures ranged from 0.46 to 0.53. The area under the curve values for the PSFS ranged from 0.801 to 0.857, suggesting a moderate ability for the PSFS to detect improvement.

DISCUSSION

The psychometric properties of the PSFS showed mixed support for construct validity but good support for the responsiveness of the PSFS when used with a heterogeneous sample of patients with HICP.

Motive Satisfaction Among Patients with Chronic Primary Pain: A Replication

We set out to replicate findings of significant (a) reductions in pain, psychological distress, and motivational incongruence (i.e., insufficient motive satisfaction) after interdisciplinary multimodal pain treatment and (b) associations between reductions in motivational incongruence (i.e., improved motive satisfaction) and decreases in psychological distress (Vincent et al., Journal of Clinical Psychology in Medical Settings 28:331-343, 2021). 475 Patients with chronic primary pain completed standardized self-reported questionnaires assessing motivational incongruence, psychological distress, pain intensity, and pain interference at intake and discharge from a tertiary psychosomatic university clinic. We used hierarchical linear models to analyze motivational incongruence's effects on psychological distress. We partially replicated Vincent et al.'s findings. Significant reductions in pain, psychological distress, and motivational incongruence after treatment were found. Reductions in motivational incongruence were associated with reductions in psychological distress. Similarly, a better motive satisfaction mediated the relationship between pain interference and psychological distress. Our findings show that reducing motivational incongruence may be a key component of treating chronic primary pain; we recommend to assess and target motivational incongruence to improve interdisciplinary multimodal pain treatment.

Can Baseline Characteristics Predict Successful Outcomes after Individual, Physiotherapist-Led Rehabilitation in Patients with Chronic Musculoskeletal Pain?

Background

No strong and consistent variables to predict outcome after pain rehabilitation have been reported in patients with chronic musculoskeletal pain. The aim of the present study was to clarify if baseline variables could predict successful outcome after a unique, individualized, physiotherapist-led rehabilitation of nine sessions.

Methods

In 274 individuals with severe chronic musculoskeletal pain, the risk ratio (RR) and 95% confidence intervals (CIs) were estimated for potentially predictive baseline variables on successful outcomes of pain management, overall health, and pain rating.

Results

Statistically significant results show that patients rating moderate or severe baseline pain were in both cases 14% less likely to improve pain management compared to patients rating mild baseline pain (RR = 0.86; 95% CI 0.77-0.97, RR = 0.86; 95% CI 0.74-1.00). Patients with the shortest pain duration were 1.61 times more likely to improve overall health (RR = 1.61; 95% CI 1.13-2.29) compared to patients reporting the longest pain duration (>5 years). Patients reporting anxiety/depression or severe pain were in both cases 1.48 times more likely to improve overall health compared to better baseline presentations (RR = 1.48; 95% CI 1.16-1.88, RR = 1.48; 95% CI 1.03-2.15). Patients with regional/generalized pain were 36% less likely to rate pain reduction (RR = 0.64; 95% CI 0.41-1.00) compared to patients rating localized baseline pain. Of 17 potentially predictive baseline variables, four reached statistical significance for at least one of the three outcomes; although none of them for all three outcomes.

Conclusions

Of 17 potentially predictive baseline variables, mild pain ratings, short pain duration, and localized baseline pain were statistically significantly associated with improvements after individual, physiotherapist-led rehabilitation for patients with chronic musculoskeletal pain. This suggests that this type of rehabilitation probably should be offered early in the pain process. Reporting anxiety/depression or severe pain at the baseline did not hinder the improvements of overall health.

[Expected areas of impact of the disciplines medicine, psychology and physiotherapy in pain treatment : A survey among members of the professions]

BACKGROUND

Interdisciplinary multimodal pain treatment (IMPT) is an essential element in the treatment of people with chronic pain. Although IMST is defined in terms of content, it is evident that its practical design is very heterogeneous. This refers not only to the composition of the contents of the treatment but also to the concrete distribution of tasks among the professions involved. This article deals with the attribution of the effect of the activities of the three professional groups involved in IMPT: medicine, psychology and physiotherapy. The aim of this work is to examine how the professions of medicine, psychology and physiotherapy assess the effectiveness of their work and the effectiveness of the other two disciplines in the care of chronic pain patients.

MATERIAL AND METHODS

A newly designed questionnaire with 19 items was used. Each item describes a possible effect that treatment by the professions of medicine, psychology and physiotherapy can have. Based on factor analysis, items were combined for which the three effect attributions had the same items. The restriction to factor analysis areas was intended to avoid redundancies in the presentation and interpretation of results. The evaluation was carried out by means of a variance analysis for the impact areas with the factors "profession" and "attribution of impact".

RESULTS

A total of 233 participants from the 3 disciplines (medicine, n = 78; psychology, n = 76; physiotherapy, n = 79) answered the questionnaire. The three areas of effect "pain reduction", "strength and movement" and "functional pain coping" could be identified by factor analysis. The impact areas attributed to the different professions are largely reflected in the participants' answers. The variance analysis revealed significant main effects for the two factors "profession" and "attribution of impact" and for their interactions.

CONCLUSION

Professionals in medicine, psychology and physiotherapy have clear expectations of their own and the other professions mentioned here with respect to their effectiveness in certain areas of change. Overall, the three professions agree in their assessment of the contribution of medicine, psychology and physiotherapy to the areas of pain reduction, gain in strength and movement and functional pain coping.

Effects of interdisciplinary pain rehabilitation programs on neuropathic and non-neuropathic chronic pain conditions - a registry-based cohort study from Swedish Quality Registry for Pain Rehabilitation (SQRP)

BACKGROUND AND AIM

Neuropathic pain arises as a direct consequence of a lesion or disease affecting the somatosensory system. Pharmacological treatments for neuropathic pain often fail despite following guidelines. Interdisciplinary Pain Rehabilitation Programs (IPRP) are an effective intervention for chronic pain conditions. Little research has investigated whether IPRP can benefit patients with chronic neuropathic pain compared to other chronic pain conditions. This study assesses the real-world effects of IPRP on patients with chronic neuropathic pain compared to non-neuropathic patients using Patient-Reported Outcome Measures (PROMs) available in the Swedish Quality Registry for Pain Rehabilitation (SQRP).

METHODS

A neuropathic group of patients (n = 1,654) were identified in two steps. This group was compared to a non-neuropathic group (n = 14,355) composed of common diagnoses (low back pain, fibromyalgia, whiplash associated disorders, and Ehlers-Danlos Syndrome) in relation to background variables, three overall outcome variables, and mandatory outcome variables (pain intensity, psychological distress symptoms, activity/participation aspects and health-related quality of life variables). Of these patients 43-44% participated in IPRP.

RESULTS

At assessment, the neuropathic group reported significantly (with small effect sizes (ES)) more physician visits the previous year, older age, shorter pain durations, and less spatial extent of the pain (moderate ES). Moreover, for the 22 mandatory outcome variables, we found only clinically insignificant differences according to ESs between the groups. For patients participating in IPRP, the neuropathic group displayed equal or in some cases slightly superior results compared to the non-neuropathic group.

DISCUSSION AND CONCLUSION

After assessing the real-world effects of IPRP, this large study found that neuropathic pain patients can benefit from the IPRP intervention. Both registry studies and RCTs are needed to better understand which patients with neuropathic pain are most suitable for IPRP and to what extent special considerations need to be made for these patients within the framework of IPRP.

Interdisciplinary Multimodal Pain Rehabilitation in Patients with Chronic Musculoskeletal Pain in Primary Care-A Cohort Study from the Swedish Quality Registry for Pain Rehabilitation (SQRP)

Chronic pain is a major public health issue. Mounting evidence suggests that interdisciplinary multimodal pain rehabilitation programs (IMMRPs) performed in specialist pain care are an effective treatment for patients with chronic pain, but the effects of such treatment if performed in primary care settings have been less studied. The aims of this pragmatic study were to (1) describe characteristics of patients participating in IMMRPs in primary care; (2) examine whether IMMRPs in primary care improve pain, disability, quality of life, and sick leave 1-year post discharge in patients with chronic pain; and (3) investigate if outcomes differ between women and men. Data from 744 (645 women and 99 men, age range 18-65 years) patients with non-malignant chronic pain included in the Swedish Quality Registry for Pain Rehabilitation Primary Care were used to describe patient characteristics and changes in health and sick leave. At 1-year follow-up, the patients had improved significantly (p < 0.01) in all health outcome measures and had reduced sick leave except in men, where no significant change was shown in physical activity level. This study indicates that MMRPs in primary care improved pain and physical and emotional health and reduced sick leave, which was maintained at the 1-year follow-up.

Improvements in pain coping predict treatment success among patients with chronic primary pain

OBJECTIVE

Given the increasing incidence and prevalence of chronic pain, effective treatments for chronic pain are needed. This study aimed to investigate the role of cognitive and behavioral pain coping regarding the prediction of treatment outcomes among inpatients with chronic primary pain participating in an interdisciplinary multimodal treatment program.

METHODS

At intake and discharge, 500 patients with chronic primary pain completed questionnaires on pain intensity, pain interference, psychological distress, and pain processing.

RESULTS

Patients' symptoms, cognitive and behavioral pain coping improved significantly after treatment. Similarly, separate cognitive and behaviroal coping skills improved significantly after treatment. Hierarchical linear models revealed no significant associations of pain coping with reductions in pain intensity. Whereas the overall level and improvements in cognitive pain coping predicted reductions in pain interference and psychological distress, the overall level and improvements in behavioral pain coping were associated with reductions in pain interference alone.

DISCUSSION

Since pain coping seems to influence both pain interference and psychological distress, improving cognitive and behavioral pain coping during an interdisciplinary multimodal pain treatment seems to be a key component in the successful treatment of inpatients with chronic primary pain, enabling them to function better physically and mentally despite their chronic pain. Clinically, it might be worth fostering and exercising cognitive restructuring as well as action planning in treatment to reduce both pain interference and psychological distress levels post-treatment. In addition, practicing relaxation techniques might help reduce pain interference post-treatment, whereas making experiences of personal competence might help reduce psychological distress post-treatment.

Feasibility and pilot testing of a personalized eHealth intervention for pain science education and self-management for breast cancer survivors with persistent pain: a mixed-method study

PURPOSE

Here, we describe the development and pilot study of a personalized eHealth intervention containing a pain science education program and self-management support strategies regarding pain and pain-related functioning in female survivors of breast cancer. First, we aimed to evaluate the eHealth intervention's acceptability, comprehensibility, and satisfaction; second, we aimed to assess its preliminary efficacy.

METHODS

A mixed-method study design was used. Breast cancer survivors with persistent pain were recruited. After 6 weeks of engagement with the eHealth intervention, acceptability, comprehensibility, and satisfaction were measured quantitatively with a self-constructed questionnaire and described qualitatively using focus groups. A joint display was used to present the meta-interferences between data. Efficacy was assessed via mixed effects models with repeated measures (outcomes assessed at baseline, 6 weeks, and 12 weeks).

RESULTS

Twenty-nine women with persistent pain after breast cancer surgery participated. Overall, the eHealth program was well received and experienced as easy to use and helpful. The eHealth intervention seems useful as an adjunct to comprehensive cancer aftercare. Efficacy estimates suggested a significant improvement in pain-related functioning, physical functioning, and quality of life.

CONCLUSION

A personalized eHealth intervention appears valuable for persistent pain management after breast cancer surgery. A large controlled clinical trial to determine effectiveness, and a full process evaluation, seems warranted.

Evaluation of content validity and feasibility of the eVISualisation of physical activity and pain (eVIS) intervention for patients with chronic pain participating in interdisciplinary pain rehabilitation programs

BACKGROUND

Chronic pain negatively influences most aspects of life, including aerobic capacity and physical function. The "eVISualisation of physical activity and pain" (eVIS) intervention was developed to facilitate individualized physical activity for treatment in interdisciplinary pain rehabilitation programs (IPRPs). The objective of this study was to evaluate the content validity and feasibility of the eVIS intervention prior to an effectiveness trial.

METHODS

In order to determine pre-clinical content validity, experts (n = 10) (patients, caregivers, researchers) participated in three assessment rounds using a Likert-scale survey where relevance, simplicity, and safety were rated, whereafter the intervention was revised. Item-content validity index (I-CVI), average, and overall CVI were used to quantify ratings. To determine content validity and feasibility in the clinical context, experts (n = 8) (patients and physiotherapists) assessed eVIS after a 2-3-week test trial, with the feasibility aspects acceptability, demand, implementation, limited efficacy-testing, and practicality in focus. Additional expert interviews (with physiotherapists, physicians) were conducted on two incomplete areas.

RESULTS

The intervention was iteratively revised and refined throughout the study. After three assessment and revision rounds, the I-CVI ratings for relevance, simplicity, and safety ranged between 0.88 and 1.00 (≥0.78) in most items, giving eVIS "excellent" content validity. In the IPRP context, the intervention emerged as valid and feasible. Additional interviews further contributed to its content validity and clinical feasibility.

CONCLUSIONS

The proposed domains and features of the eVIS intervention are deemed valid in its content and feasible in the IPRP context. The consecutive step-by-step evaluation process enabled careful intervention development with revisions to be made in close collaboration with stakeholders. Findings implicate a robust base ahead of the forthcoming effectiveness trial.

Pain intensity and psychological distress show different associations with interference and lack of life control: A clinical registry-based cohort study of >40,000 chronic pain patients from SQRP

Background

Both chronic pain and depressive and/or anxiety symptoms are associated with negative impacts on daily living, including interference and lack of life control. However, little is known about how pain and psychological distress affect these impacts.

Aim

The first aim was to assess how pain intensity, psychological distress, and social support interact with interference and lack of life control. A second aim was to investigate whether the strength of these relationships is moderated by the presence or absence of depression and/or anxiety.

Subjects and methods

Patient-Reported Outcome Measures (PROMs), which are available in the Swedish Quality Registry for Pain Rehabilitation (SQRP), were retrieved for patients with chronic pain (N = 40,184). A theoretical model with the constructs/latent variables pain intensity, psychological distress, interference, lack of life control, and social support was proposed and analyzed using Partial Least Squares Structural Equation Modelling (PLS-SEM). Indicators for these constructs were identified from the PROMs of the SQRP. Two models of the total cohort, which differed with respect to the causal relationship between pain intensity and psychological distress, were investigated. The moderating effects of anxiety and/or depression were also analyzed.

Results

Relatively low correlation and explanatory power (R ²= 0.16) were found for the pain intensity-psychological distress relationship. Pain intensity had a stronger effect on interference than on lack of life control. The reverse was found for psychological distress - i.e., psychological distress seemed to have a higher negative influence on function than on interference. The underlying assumption of the causal relationship between pain intensity and psychological distress determined how strong pain intensity and psychological distress influenced interference and lack of life control. Social support showed very similar absolute significant correlations with interference and lack of life control. Interference and lack of life control showed relatively weak associations. The psychological distress level was a moderating factor for several of the paths investigated.

Discussion and conclusion

A clinical treatment consequence of the low correlation between pain intensity and psychological distress may be that clinically treating one may not reduce the effect of the other. The relative importance of pain intensity and psychological distress on interference and lack of life control depends on the underlying assumption concerning the pain intensity-psychological distress relationship. Interference and lack of life control showed relatively weak associations, underscoring the need to clinically assess them separately. Social support influenced both impact constructs investigated. The cohort display heterogeneity and thus presence of definite signs of anxiety and/or depression or not was a moderating factor for several of the associations (paths) investigated. The results are important both for the assessments and the design of treatments for patients with chronic pain.

Assessment of visceral pain with special reference to chronic pancreatitis

A thorough pain assessment is of utmost importance when managing pain in clinical practice as it is the foundation for defining pain in need of treatment, either interventional or pharmacological. Pain characteristics can also guide interventional strategies and help evaluate the effect of treatment. In research settings, standardized pain assessment is crucial to improve comparability across studies and facilitate meta-analysis. Due to the importance of thorough visceral pain assessment, this manuscript describes the key elements of pain evaluation focusing on chronic pancreatitis. Most studies in pain assessment have focused on somatic pain, and although chronic pain often shares characteristics between etiologies, some differences must be addressed when assessing visceral pain. Especially differences between somatic and visceral pain are apparent, where visceral pain is diffuse and difficult to localize, with referred pain aspects and often autonomic symptoms dominating the clinical picture. These aspects need to be incorporated into the pain assessment instrument. The manuscript will discuss the different ways of assessing pain, including unidimensional measurement scales, multidimensional questionnaires, and quantitative sensory testing. The advantages and challenges linked to the different methods will be evaluated.

The core minimum dataset for measuring pain outcomes in pain services across Scotland. Developing and testing a brief multi-dimensional questionnaire

Background

There is currently no agreed minimum dataset to inform specialist chronic pain service provision. We aimed to develop a Core Minimum Dataset (CMD) for pain services in Scotland and perform preliminary analysis to evaluate its psychometric properties in adults with chronic pain.

Methods

The questionnaire was developed following a review of existing relevant data collection instruments and national consultation. The CMD questionnaire was completed alongside a routine pre-clinic questionnaire by patients attending two pain services over 3 months. Concurrent validity was tested by comparing scores between the CMD and pre-existing questionnaires. Reliability was assessed by test-retest and discriminative validity via receiver operating characteristic (ROC) curves.

Results

The final CMD questionnaire consisted of five questions on four domains: pain severity (Chronic Pain Grade [CPG] Q1); pain interference (CPG Q5); emotional impact (Patient Health Questionnaire-2 [PHQ-2], two questions); and quality of life (Short Form Health Survey-36 [SF-36] Q1). 530 patients completed the questionnaire. Strong correlation was found with the Hospital Anxiety and Depression Scale (rs = 0.753, p < 0.001). Moderate correlations were found with the Brief Pain Inventory for pain interference (rs = 0.585, p < 0.001) and pain severity (rs = 0.644, p < 0.001). Moderate to good reliability was demonstrated (Intra-class Correlation Coefficient = 0.572-0.845). All items indicated good discrimination for relevant health states.

Conclusions

The findings represent initial steps towards developing an accurate questionnaire that is feasible for assessing chronic pain in adults attending specialist pain clinics and measuring service improvements in Scotland. Further validation testing, in clinical settings, is now required.

Determinants of responsiveness to multidisciplinary chronic pain management interventions: protocol for a systematic review and meta-analysis

INTRODUCTION

The current manuscript presents a protocol for a systematic review and meta-analysis of the evidence regarding the determinants of responsiveness to multidisciplinary management of chronic pain, with pain intensity, pain-related interference, physical functioning and health-related quality of life as the main outcomes, with consideration to multiple secondary outcomes.

METHODS AND ANALYSIS

To identify relevant studies, the Ovid MEDLINE, PubMed, Ovid PsycINFO, EBSCO CINAHL and Scopus databases will be searched for all studies exploring factors associated with responsiveness to multidisciplinary pain management from study inception to the present. Cohorts, case-control studies and randomised controlled trials will be included. Independent screening for eligible studies will be completed by a total of four researchers using defined criteria. Data extraction will be executed by two researchers. Study heterogeneity will be estimated using the I² index. A meta-analysis will be performed using random effects models. Publication bias will be evaluated by means of funnel plots and Egger's test.

ETHICS AND DISSEMINATION

The proposed study does not involve collection of primary data. Therefore, no ethical approval is required. The results of the systematic review and meta-analysis will be presented in a peer-reviewed journal and at conferences.

PROSPERO REGISTRATION NUMBER

CRD42021236424.

Longitudinal resting-state electroencephalography in patients with chronic pain undergoing interdisciplinary multimodal pain therapy

ABSTRACT

Chronic pain is a major healthcare issue posing a large burden on individuals and society. Converging lines of evidence indicate that chronic pain is associated with substantial changes of brain structure and function. However, it remains unclear which neuronal measures relate to changes of clinical parameters over time and could thus monitor chronic pain and treatment responses. We therefore performed a longitudinal study in which we assessed clinical characteristics and resting-state electroencephalography data of 41 patients with chronic pain before and 6 months after interdisciplinary multimodal pain therapy. We specifically assessed electroencephalography measures that have previously been shown to differ between patients with chronic pain and healthy people. These included the dominant peak frequency; the amplitudes of neuronal oscillations at theta, alpha, beta, and gamma frequencies; as well as graph theory-based measures of brain network organization. The results show that pain intensity, pain-related disability, and depression were significantly improved after interdisciplinary multimodal pain therapy. Bayesian hypothesis testing indicated that these clinical changes were not related to changes of the dominant peak frequency or amplitudes of oscillations at any frequency band. Clinical changes were, however, associated with an increase in global network efficiency at theta frequencies. Thus, changes in chronic pain might be reflected by global network changes in the theta band. These longitudinal insights further the understanding of the brain mechanisms of chronic pain. Beyond, they might help to identify biomarkers for the monitoring of chronic pain.

Quality of Life and Mental Distress in Patients with Chronic Low Back Pain: A Cross-Sectional Study

The aim of this study was to examine the levels of health-related quality of life (HRQoL), pain intensity, and mental distress in participants with chronic low back pain (CLBP), and to examine the differences in the HRQoL of participants with respect to mental distress and the correlations of the examined variables. Data were collected from 148 patients using the SF-36 Health Status Questionnaire (SF-36), the Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM) questionnaire, and the visual-analog pain scale (VAS). The results indicate poorer self-assessment of physical health (Me = 28.1) compared to mental health (Me = 39.4). Participants with higher levels of mental distress reported significant emotional limitations (p = 0.003), lower energy (p < 0.001), poorer psychological health (p < 0.001) and social functioning (p < 0.001), more pain (p = 0.007), and, ultimately, poorer general health (p < 0.001). The level of mental distress was related to the level of HRQoL, while a correlation with the level of pain of the participants was not found. The study results indicate a connection between the presence of mental distress and almost all aspects of HRQoL in participants with CLBP.

Reported Outcomes in Interdisciplinary Pain Treatment: An Overview of Systematic Reviews and Meta-Analyses of Randomised Controlled Trials

Background

There is considerable diversity of outcome selections and methodologies for handling the multiple outcomes across all systematic reviews (SRs) of Interdisciplinary Pain Treatment (IPT) due to the complexity. This diversity presents difficulties for healthcare decision makers. Better recommendations about how to select outcomes in SRs (with or without meta-analysis) are needed to explicitly demonstrate the effectiveness of IPT.

Objective

This overview systematically collates the reported outcomes and measurements of IPT across published SRs and identifies the methodological characteristics. Additionally, we provide some suggestions on framing the selection of outcomes and on conducting SRs of IPT.

Methods

Three electronic databases (PubMed, Cochrane Library, and Epistemonikos) and the PROSPERO registry for ongoing SR were supplemented with hand-searching ending on 30 September 2021.

Results

We included 18 SRs with data on 49007 people from 356 primary randomised controlled trials (RCTs); eight were followed by meta-analysis and ten used narrative syntheses of data. For all the SRs, pain was the most common reported outcome (72%), followed by disability/functional status (61%) and working status (61%). Psychological well-being and quality of life were also reported in half of the included SR (50%). The core outcome domains according to VAPAIN, IMMPACT, and PROMIS were seldom met. The methodological quality varied from critically low to moderate according to AMSTAR2. The AMSTAR2 rating was negatively correlated to the number of outcome domains in PROMIS, and VAPAIN was positively correlated with IMMPACT and PROMIS, indicating the intercorrelations between the reported outcomes.

Conclusion

This systematic overview showed wide-ranging disparity in reported outcomes and applied outcome domains in SRs evaluating IPT interventions for chronic pain conditions. The intercorrelations between the reported outcomes should be appropriately handled in future research. Some approaches are discussed as well.

Prognostic Factors for Quality of Life After Interdisciplinary Pain Rehabilitation in Patients with Chronic Pain-A Systematic Review

BACKGROUND

Health-related quality of life (hrQoL) is a core outcome in evaluating interdisciplinary pain rehabilitation (IPR). This systematic review aimed to identify prognostic factors for hrQoL at least six months after IPR in chronic pain patients.

METHODS

A systematic search was conducted in MEDLINE, PsycINFO, EMBASE, CINAHL, Web of Science and Cochrane CENTRAL until September 2020. Included were prognostic studies on the outcome hrQoL in adults aged 18 to 67 years with chronic pain (excluding malignancies, systemic-, inflammatory or degenerative joint diseases) who had undergone IPR. Studies were assessed with The Quality in Prognostic Studies-tool. Potential prognostic factors at baseline for the domains pain, psychological and physical functioning were qualitatively synthesized for hrQoL. Grading of Recommendations Assessment, Development and Evaluation was used to evaluate the level of evidence.

RESULTS

Fourteen studies on 6,668 participants (mean age 37.4-52.8 y), with musculoskeletal pain/fibromyalgia and a pain duration ranging between 13.1 and 177.4 months were considered eligible. With a very low certainty of evidence, pain intensity, emotional distress, and physical functioning at baseline were inconsistent for prediction of hrQoL and pain duration was not predictive. With low certainty of evidence, fewer pain sites, lower levels of negative cognitive behavioral factors, and higher levels of positive cognitive behavioral factors predicted a better outcome.

CONCLUSIONS

The overall certainty of evidence was low to very low, making it difficult to reach definitive conclusions at present. Future studies with a predefined core set of predictors investigating hrQoL in patients with chronic pain after IPR are needed.

The Critical Role of Nutrition Care to Improve Pain Management: A Global Call to Action for Physical Therapist Practice

Physical therapists have unique education in the comprehensive biopsychosocial assessment and treatment of chronic pain and its mechanisms. Recently, physical therapists have raised awareness regarding the impact of nutrition on promoting health and managing noncommunicable diseases. Robust evidence supports the implementation of nutrition in physical therapist education and practice. Of particular interest for the physical therapist are investigations that use dietary interventions for the treatment of chronic pain. Yet physical therapists have received little guidance regarding their role in nutrition care for pain management and may pass on opportunities to counsel their patients on the connection between nutrition and pain. Therefore, a clinical paradigm shift and unified voice within the profession is called on to encourage physical therapists to develop tailored multimodal lifestyle interventions that include nutrition care for the management of chronic pain. This Perspective describes evidence supporting the implementation of nutrition care in physical therapist practice, supports the role of nutritional pain management for physical therapists, and encourages the use of nutrition care for primary, secondary, tertiary, prevention, health promotion, and wellness related to chronic pain. To achieve these aims, this Perspective offers suggestions for how physical therapists can (1) enhance clinical decision making; (2) expand professional, jurisdictional, and personal scope of practice; (3) evolve entry-level education; and (4) stimulate new investigations in nutrition care and pain science research. In doing so, physical therapists can assert their role throughout the pain management continuum, champion innovative research initiatives, and enhance public health by reducing the impact of chronic pain.

IMPACT

The nutrition care process for pain management is defined as the basic duty to provide adequate and appropriate nutrition education and counseling to people living with pain. Including the nutrition care process as part of a multimodal approach to pain management provides an opportunity for physical therapists to assert their role throughout the pain management continuum. This includes championing innovative research initiatives and enhancing public health by reducing the impact of chronic pain for over 50 million Americans.

Health-related quality of life in patients with chronic orofacial pain compared with other chronic pain patients

Background

Health‐related quality of life (HRQoL) of orofacial pain patients is lower than that of the general population and impaired in multiple dimensions. The aim of the present study was to investigate HRQoL of orofacial pain patients in comparison with patients suffering from other chronic pain disorders.

Materials and Methods

One hundred and fifty‐one tertiary care facial pain patients (mean age, 50 years; standard deviation [SD], 15; 119 females), were compared with 312 other non‐cancer chronic pain patients (mean age, 46 years; SD, 13; 204 women), recruited from three multidisciplinary pain clinics in Finland. The groups were compared using the 15D, and pain‐related measures such as pain interference, pain acceptance, anxiety, depression, and sleep. Statistical comparisons between groups were done using t test, χ² test, or analysis of covariance. Multivariate linear regression analysis was used to study whether pain‐related aspects influencing HRQoL are similar between the patient groups.

Results

The 15D score was significantly higher in facial pain patients (0.823; SD, 0.114) indicating better HRQoL in comparison with other chronic pain patients (0.732; SD, 0.107) (p < .001). The 15D profiles of studied populations resembled each other but orofacial pain patients showed significantly higher scores for most individual 15D dimensions. Dimensions regarding discomfort and symptoms and sleep were most affected in both groups. Orofacial pain patients showed less psychosocial disability and better acceptance of their pain. Pain acceptance was a weaker explanatory factor of HRQoL in orofacial pain patients.

Conclusion

Compared to other non‐cancer chronic pain, chronic pain in the orofacial area causes less impairment in HRQoL. Orofacial pain patients showed less psychosocial disability and better pain acceptance.

Longitudinal outcome evaluations of Interdisciplinary Multimodal Pain Treatment programmes for patients with chronic primary musculoskeletal pain: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Although Interdisciplinary Multimodal Pain Treatment (IMPT) programmes share a biopsychosocial approach to increase the wellbeing of patients with chronic pain, substantial variation in content and duration have been reported. In addition, it is unclear to what extent any favourable health outcomes are maintained over time. Therefore, our first aim was to identify and analyse the change over time of patient-related outcome measures in cohorts of patients who participated in IMPT programmes. Our second aim was to acquire insight into the heterogeneity of IMPT programmes.

DATABASES AND DATA TREATMENT

The study protocol was registered in Prospero under CRD42018076093. We searched Medline, Embase, PsycInfo and Cinahl from inception to May 2020. All study selection, data extraction and risk of bias assessments were independently performed by two researchers. Study cohorts were eligible if they included adult patients with chronic primary musculoskeletal pain for at least 3 months. We assessed the change over time, by calculating pre-post, post-follow-up and pre-follow-up contrasts for seven different patient-reported outcome domains. To explore the variability between the IMPT programmes, we summarized the patient characteristics and treatment programmes using the intervention description and replication checklist.

RESULTS

The majority of the 72 included patient cohorts significantly improved during treatment. Importantly, this improvement was generally maintained at follow-up. In line with our expectations and with previous studies, we observed substantial methodological and statistical heterogeneity.

CONCLUSIONS

This study shows that participation in an IMPT programme is associated with considerable improvements in wellbeing that are generally maintained at follow-up. The current study also found substantial heterogeneity in dose and treatment content, which suggests different viewpoints on how to optimally design an IMPT programme.

SIGNIFICANCE

The current study provides insight into the different existing approaches regarding the dose and content of IMPT programs. This analysis contributes to an increased understanding of the various approaches by which a biopsychosocial perspective on chronic pain can be translated to treatment programs. Furthermore, despite theoretical and empirical assertions regarding the difficulty to maintain newly learned health behaviors over time, the longitudinal analysis of health outcomes did not find a relapse pattern for patients who participated in IMPT programs.

Assessment of pain associated with chronic pancreatitis: An international consensus guideline

Pain is the most common symptom in chronic pancreatitis (CP) with a major impact on quality of life. Few validated questionnaires to assess pain in CP exist, and the lack of consensus negatively impacts clinical management, research and meta-analysis. This guideline aims to review generic pain questionnaires for their usability in CP, to outline how pain assessment can be modified by confounding factors and pain types, to assess the value of additional measures such as quality of life, mental health and quantitative sensory testing, and finally to review pain assessment questionnaires used specifically in CP. A systematic review was done to answer 27 questions that followed the PICO (Population; Intervention; Comparator; Outcome) template. Quality of evidence of the statements was judged by Grades of Recommendation, Assessment, Development and Evaluation (GRADE) criteria. The manuscript was sent for review to 36 experts from various disciplines and continents in a multi-stage Delphi process, and finally reviewed by patient representatives. Main findings were that generic pain instruments are valid in most settings, but aspects of pain are specific for CP (including in children), and instruments have to account for the wide phenotypic variability and development of sensitization of the central nervous system. Side effects to treatment and placebo effects shall also be considered. Some multidimensional questionnaires are validated for CP and are recommended together with assessment of quality of life and psychiatric co-morbidities. This guideline will result in more homogeneous and comprehensive pain assessment to potentially improve management of painful CP.

The Impact of Parental Presence on their Children during Painful Medical Procedures:A Systematic Review

OBJECTIVE

Whether parental presence during their children's painful medical procedures is advantageous with regard to child's pain-related outcomes is questionable. Research regarding this topic is equivocal and additional questions, such as whether levels of parental involvement may play a role as well, remain to be assessed. The purpose of this systematic review is to summarize and critically appraise the literature regarding the impact of parental presence versus absence during their children's painful medical procedures on the child's pain-related outcomes.

METHODS

The review protocol was registered on Prospero (ID CRD42018116614). A systematic search in PubMed, Web of Science, and PsycArticles resulted in 22 eligible studies incorporating 2157 participants. Studies were considered eligible if they included children (≤ 18 years old) undergoing a painful medical procedure and compared parental presence and/or involvement with parental absence during the procedure.

RESULTS

The children's pain-related outcomes included self-reported pain intensity, self-reported fear, anxiety and distress, observed pain-related behavior, and physiological parameters. Overall, evidence points in the direction of beneficial effects of parental presence versus absence with regard to children's self-reported pain intensity and physiological parameters, whereas mixed findings were recorded for children's self-reported fears, anxiety and distress, and observed pain-related behaviors.

CONCLUSIONS

: In order to provide clear recommendations on how to involve the parent during the procedure, as well as for which type of children and parents parental presence has the best effects, further research is needed, as indicated in this review.

Systematic Review on Pain-Related Outcome Domains After Sternotomy: A First Step Toward the Development of a Core Outcome Set

OBJECTIVES

Pain after surgery has a major impact on acute and long-term recovery and quality of life, but its management is often insufficient. To enhance the quality of research and to allow for better comparability between studies, it is important to harmonize outcomes for assessing the efficacy and effectiveness of pain management interventions after surgery. As a first step in developing a core outcome set, this study aimed to systematically search for outcome domains assessed in research regarding acute pain management after sternotomy as an example of a typically painful surgical procedure.

METHODS

A systematic literature review was performed using MEDLINE, Embase, and CENTRAL. Eligibility criteria consisted of randomized controlled trials and observational trials targeting pain management after sternotomy in adults in the acute postoperative setting (≤2 weeks). After duplicate removal and title and abstract screening by 2 independent reviewers, study characteristics and outcome domains were identified, which were extracted from full texts and summarized qualitatively.

RESULTS

Of 1350 studies retrieved by database searching, 156 studies were included for full-text extraction. A total of 80 different outcome domains were identified: pain intensity, analgesic consumption, physiological function, and adverse events were the most frequent ones. Outcome domains were often not explicitly reported, and the combination of domains and assessment tools was heterogeneous. The choice of outcomes is commonly made within clinicians; patients' perspectives are not considered.

CONCLUSIONS

The wide variety of commonly applied outcome domains, the nonexplicit wording, and the heterogeneous combination of the domains indicating treatment benefit demonstrate the need for harmonization of outcomes assessing perioperative pain management after surgery.

Do quality of life, anxiety, depression and acceptance improve after interdisciplinary pain rehabilitation? A multicentre matched control study of acceptance and commitment therapy-based versus cognitive-behavioural therapy-based programmes

OBJECTIVE

Interdisciplinary pain rehabilitation (IPR) usually employs a cognitive-behavioural therapeutic (CBT) approach. However, there is growing support for chronic pain treatments based on acceptance and commitment therapy (ACT). Most studies of ACT and CBT for chronic pain have evaluated their effects after psychological interventions, not after IPR. We compared the results of an ACT-based IPR programme with two CBT-based IPR programmes.

METHODS

We used a retrospective multicentre pretest-posttest design with matched patient groups at three centres. Data were collected from the Swedish Quality Registry for Pain Rehabilitation before and after IPR participation. Participants completed the EQ-5D health-related quality of life questionnaire, the Chronic Pain Acceptance Questionnaire, (CPAQ) and the Hospital Anxiety and Depression Scale (HADS). Analyses were performed to compare the effects of the different interventions.

RESULTS

Neither EQ-5D nor HADS depression scores were affected by the psychological approach used. The score changes on both CPAQ subscales (activity engagement and pain willingness) indicated significant improvements between admission and discharge at all centres.

CONCLUSIONS

These findings indicate the effectiveness of using psychological approaches to manage chronic pain. Both CBT and ACT had a beneficial effect on most of the assessed health-related parameters.

[Characteristic values and test statistical goodness of the Veterans RAND 12-Item Health Survey (VR-12) in patients with chronic pain : An evaluation based on the KEDOQ pain dataset]

The Veterans RAND 12-Item Health Survey (VR-12) was added to the German Pain Questionnaire (DSF) as a self-report measure of health-related quality of life in 2016, replacing the previously used SF-12, which required a license. Both measures have 12 items and include a physical component summary (PCS) and a mental component summary (MCS). Evaluations with a larger sample on characteristic values and on the test-statistical goodness of the VR-12 in patients with chronic pain are so far missing. Data on the VR-12 and other procedures of the DSF were evaluated from 11,644 patients from 31 centers participating in KEDOQ pain. The patients filled out the DSF before starting a pain therapy treatment. Change sensitivity was determined for 565 patients for whom the VR-12 was available from a follow-up questionnaire of the DSF several months after the initial survey.The reliability (Cronbach's alpha) of the PCS was r_tt = 0.78 and for the MCS r_tt = 0.84. The MCS had significant relationships with the depression, anxiety and stress scales (r = -0.51 to r = -0.72), and the PCS correlated more highly with areas of pain-related impairment (r = -0.48 to r = -0.52). Patients with higher pain chronicity, those with higher pain severity, and those with evidence of high psychological distress described significantly lower health-related quality of life in PCS and MCS. The effect size (ES) of change in terms of improvement in health-related quality of life was ES = 0.33 in the MCS and ES = 0.51 in the PCS.The results are in agreement with the findings of the SF-36 and SF-12 in patient collectives with chronic pain. In summary, they show that the VR-12 is an adequate substitute for the SF-12 in the German pain questionnaire.

The value of interdisciplinary treatment for sickness absence in chronic pain: A nationwide register-based cohort study

BACKGROUND

Interdisciplinary treatment (IDT) is an internationally recommended intervention for chronic pain, despite inconclusive evidence of its effects on sickness absence.

METHODS

With data from 25,613 patients in Swedish specialist healthcare, we compared sickness absence, in the form of both sick leave and disability pensions, over a 5-year period between patients either allocated to an IDT programme or to other/no interventions (controls). To obtain population-average estimates, a Markov multistate model with theory-based inverse probability weights was used to compute both the proportion of patients on sickness absence and the total sickness absence duration.

RESULTS

IDT patients were more likely than controls to receive sickness absence benefits at any given time (baseline: 49% vs. 46%; 5-year follow-up: 36% vs. 35%), and thereby also had a higher total duration, with a mean (95% CI) of 67 (87, 48) more days than controls over the 5-year period. Intriguingly, sick leave was higher in IDT patients (563 [552, 573] vs. 478 [466, 490] days), whereas disability pension was higher in controls (152 [144, 160] vs. 169 [161, 178] days).

CONCLUSION

Although sickness absence decreased over the study period in both IDT patients and controls, we found no support for IDT decreasing sickness absence more than other/no interventions in chronic pain patients.

SIGNIFICANCE

In this large study of chronic pain patients in specialist healthcare, sickness absence is compared over a 5-year period between patients in an interdisciplinary treatment programme and other/no interventions. Sickness absence decreased over the study period in bothgroups; however, there was no support forthat it decreased more with interdisciplinary treatment than alternative interventions.

Outcomes of Interdisciplinary Pain Rehabilitation Across Subgroups of the Multidimensional Pain Inventory - A Study From the Swedish Quality Registry for Pain Rehabilitation

INTRODUCTION

The Multidimensional Pain Inventory (MPI) is frequently used in the assessment of chronic pain. Three subgroups have been derived from MPI: adaptive coper (AC), dysfunctional (DYS), and interpersonally distressed (ID). The primary aim of this study was to examine whether outcome of Interdisciplinary Multimodal Pain Rehabilitation Programs (IMMRPs) differed across the MPI subgroups.

METHODS

Patients with chronic pain (N = 34,513), included in the Swedish Quality Registry for Pain Rehabilitation, were classified into MPI subgroups and a subset that participated in IMMRPs (N = 13,419) was used to examine overall treatment outcomes using a previously established Multivariate Improvement Score (MIS) and 2 retrospective patient-evaluated benefits from treatment.

RESULTS

The subgroups differed on sociodemographic characteristics, pain duration, and spatial spreading of pain. DYS and ID had the best overall outcomes to MIS. AC had the best outcomes according to the 2 retrospective items. Transition into other subgroups following IMMRP was common and most prominent in DYS and least prominent in AC.

CONCLUSION

The validity of the MPI subgroups was partially confirmed. DYS and ID had the most severe clinical presentations at baseline and showed most improvement following IMMRP, but overall severity in DYS and ID at post-treatment was still higher than in the AC group. Future studies should examine how processes captured by MPI interact with neurobiological, medical, sociodemographic, and adaptation/coping factors and how these interactions impact severity of chronic pain and treatment outcome.

Comprehensiveness and validity of a multidimensional assessment in patients with chronic low back pain: a prospective cohort study

Background

Chronic low back pain is a multidimensional syndrome affecting physical activity and function, health-related quality of life and employment status. The aim of the study was to quantify the cross-sectional and longitudinal validity of single measurement scales in specific construct domains and to examine how they combine to build a comprehensive outcome, covering the complex construct of chronic low back pain before and after a standardized interdisciplinary pain program.

Methods

This prospective cohort study assessed 177 patients using the Short Form 36 (SF-36), the Multidimensional Pain Inventory (MPI), the Symptom Checklist-90-Revised (SCL-90-R), the Oswestry Disability Index (ODI), and 2 functional performance tests, the Back Performance Scale (BPS) and the 6-Minute Walking Distance (6MWD). The comprehensiveness and overlap of the constructs used were quantified cross-sectionally and longitudinally by bivariate correlations, exploratory factor analysis, and effect sizes.

Results

The mean age of the participants was 48.0 years (+/− 12.7); 59.3% were female. Correlations of baseline scores ranged from r = − 0.01 (BPS with MPI Life control) to r = 0.76 (SF-36 Mental health with MPI Negative mood). SF-36 Physical functioning correlated highest with the functional performance tests (r = 0.58 BPS, 0.67 6MWD) and ODI (0.56). Correlations of change scores (difference of follow-up – baseline score) were consistent but weaker. Factor analysis revealed 2 factors: “psychosocial” and “pain & function” (totally explained variance 44.0–60.9%). Psychosocial factors loaded strongest (up to 0.89 SCL-90-R) on the first factor, covering 2/3 of the explained variance. Pain and function (ing) loaded more strongly on the second factor (up to 0.81 SF-36 Physical functioning at follow-up). All scales showed improvements, with effect sizes ranging from 0.16–0.67.

Conclusions

Our results confirm previous findings that the chronic low back pain syndrome is highly multifactorial and comprises many more dimensions of health and quality of life than merely back-related functioning. A comprehensive outcome measurement should include the predominant psychosocial domain and a broad spectrum of measurement constructs in order to assess the full complexity of the chronic low back syndrome. Convergence and divergence of the scales capture the overlapping contents and nuances within the constructs.

Short-term impact of the COVID-19 pandemic on patients with a chronic pain disorder

The current Covid-19 pandemic has already had a definite impact on the daily life of many people worldwide. It has been proposed that people with preexisting medical conditions will be harder hit by the pandemic and the subsequent measures to contain the spread of the disease. In this questionnaire-based, observational study, we aimed to assess the impact of the pandemic on patients with a chronic pain disorder, who are treated at a tertiary multidisciplinary pain center.Participants rated the impact of the pandemic on their chronic pain disorder using a self-designed questionnaire. Also, participants filled out the regular follow-up questionnaire to assess a chronic pain disorder measuring among other parameters pain intensity, symptoms of depression, anxiety, stress, and pain-related quality of life.Of 136 eligible patients who presented to our pain center between May 5th and July 17th, 112 agreed to participate in the study (82.4%). Eighty two participants (73.2%) reported a deterioration of the pain disorder using the self-designed questionnaire. The more robust parameters of the regular follow-up questionnaire showed no relevant changes compared to data collected before the pandemic. We were not able to detect any demographic and medical parameters that were clinically relevantly associated with a higher impact of the pandemic.We conclude that a chronic pain disorder is a relatively stable disease that does not change significantly due to external factors, like the Covid-19 pandemic, even if the subjective impact is perceived to be high.

[Measurement of pain-related experiential avoidance: analysis of the Acceptance and Action Questionnaire-II-Pain in patients with chronic pain]

Einleitung und Fragestellung

Erlebensvermeidung („experiential avoidance“) stellt einen zentralen störungsrelevanten Prozess im Rahmen der Akzeptanz- und Commitment-Therapie (ACT) dar. Zur Erfassung wurde der Acceptance and Action Questionnaire II (AAQ-II) entwickelt und in den Niederlanden für eine Patientengruppe mit chronischem Schmerz adaptiert und validiert (AAQ-II‑P). Hohe Werte im AAQ-II‑P bedeuten hohe schmerzbezogene Erlebensvermeidung. Ziel unserer Untersuchung ist die Erfassung von schmerzbezogener Erlebensvermeidung mit einer deutschen Version des AAQ-II‑P bei chronischen Schmerzpatienten und die Prüfung psychometrischer Merkmale des Messverfahrens.

Methodik

Der AAQ-II wurde mittels eines Vorwärts-Rückwärts-Verfahrens ins Deutsche übersetzt, für chronischen Schmerz adaptiert (AAQ-II‑P) und von 168 Patienten einer universitären Schmerzambulanz beantwortet. Zusätzlich wurden Daten zu schmerzbedingter Beeinträchtigung (CPG: Schweregrad nach von Korff) und Schmerzkatastrophisieren (PCS) erhoben sowie zu gesundheitsbezogener Lebensqualität (SF-12), Angst und Depressivität (HADS-D). Ebenfalls erfasst wurden allgemeine Persönlichkeitsmerkmale (BFI‑K) und habituelle Achtsamkeit (KIMS-S). Ausgewertet wurden Reliabilität und faktorielle Validität des AAQ-II‑P sowie seine Beziehung zu den anderen psychometrischen Verfahren.

Ergebnisse

Der AAQ-II‑P erzielte eine hohe interne Konsistenz mit α = 0,89 sowie eine eindimensionale Faktorenstruktur mit 61 % aufgeklärter Varianz. Geringe Korrelationen ergaben sich zu Persönlichkeitsdimensionen (maximal r = 0,44 zu Neurotizismus) und Achtsamkeit (maximal r = −0,43 zu Akzeptanz). Ein hoher Zusammenhang fand sich zu Schmerzkatastrophisieren (r = 0,75), Depression (r = 0,73) und Angst (r = 0,66). Die Beziehung zu Lebensqualität war am stärksten ausgeprägt auf der Psychischen Summenskala (r = −0,58).

Diskussion und Schlussfolgerung

Die deutsche Version des AAQ-II‑P hat eine gute Reliabilität und weist hinsichtlich Zuverlässigkeit und Faktorenstruktur hohe Vergleichbarkeit mit der Originalversion auf. Die Beziehungen zu den Skalen der psychometrischen Verfahren sind zumeist in erwarteter Richtung und Höhe. Patienten mit chronischem Schmerz und hoher schmerzbezogener Erlebensvermeidung tendieren deutlich zum Schmerzkatastrophisieren und zeichnen sich durch schlechtere psychische Lebensqualität aus. Dies spricht für die Relevanz des Konstrukts hinsichtlich therapeutischer Zielvariablen.

Spreading of Pain in Patients with Chronic Pain is Related to Pain Duration and Clinical Presentation and Weakly Associated with Outcomes of Interdisciplinary Pain Rehabilitation: A Cohort Study from the Swedish Quality Registry for Pain Rehabilitation (SQRP)

Introduction

The extent to which pain is distributed across the body (spreading of pain) differs largely among patients with chronic pain conditions and widespread pain has been linked to poor quality of life and work disability. A longer duration of pain is expected to be associated with more widespread pain, but studies are surprisingly scarce. Whether spreading of pain is associated with clinical presentation and treatment outcome in patients seen in interdisciplinary multimodal pain rehabilitation programs (IMMRPs) is unclear. The association between spreading of pain and (1) pain duration (2) clinical presentation (eg, pain intensity, pain-related cognitions, psychological distress, activity/participation aspects and quality of life) and (3) treatment outcome were examined.

Methods

Data from patients included in the Swedish Quality Registry for Pain Rehabilitation were used (n=39,916). A subset of patients that participated in IMMRPs (n=14,666) was used to examine whether spreading of pain at baseline predicted treatment outcome. Spreading of pain was registered using 36 predefined anatomical areas which were summarized and divided into four categories: 1–6 regions with pain (20.6% of patients), 7–12 regions (26.8%), 13–18 regions (22.0%) and 19–36 regions (30.6%).

Results

More widespread pain was associated with a longer pain duration and a more severe clinical picture at baseline with the strongest associations emerging in relation to health and pain aspects (pain intensity, pain interference and pain duration). Widespread pain was associated with a poorer overall treatment outcome following IMMRPs at both posttreatment and at a 12-month follow-up, but effect sizes were small.

Discussion

Spreading of pain is an indicator of the duration and severity of chronic pain and to a limited extent to outcomes of IMMRP. Longer pain duration in those with more widespread pain supports the concept of early intervention as clinically important and implies a need to develop and improve rehabilitation for patients with chronic widespread pain.

Psychometric properties of Short Form-36 Health Survey, EuroQol 5-dimensions, and Hospital Anxiety and Depression Scale in patients with chronic pain

Supplemental Digital Content is Available in the Text.

This large-sample item response theory-based evaluation assessed the measurement properties of SF-36, EQ-5D, and hospital anxiety and depression scale for chronic pain patients in clinical settings.

Recent research has highlighted a need for the psychometric evaluation of instruments targeting core domains of the pain experience in chronic pain populations. In this study, the measurement properties of Short Form-36 Health Survey (SF-36),EuroQol 5-dimensions (EQ-5D) and Hospital Anxiety and Depression Scale (HADS) were analyzed within the item response-theory framework based on data from 35,908 patients. To assess the structural validity of these instruments, the empirical representations of several conceptually substantiated latent structures were compared in a cross-validation procedure. The most structurally sound representations were selected from each questionnaire and their internal consistency reliability computed as a summary of their precision. Finally, questionnaire scores were correlated with each other to evaluate their convergent and discriminant validity. Our results supported that SF-36 is an acceptable measure of 2 independent constructs of physical and mental health. By contrast, although the approach to summarize the health-related quality of life construct of EQ-5D as a unidimensional score was valid, its low reliability rendered practical model implementation of doubtful utility. Finally, rather than being separated into 2 subscales of anxiety and depression, HADS was a valid and reliable measure of overall emotional distress. In support of convergent and discriminant validity, correlations between questionnaires showed that theoretically similar traits were highly associated, whereas unrelated traits were not. Our models can be applied to score SF-36 and HADS in chronic pain patients, but we recommend against using the EQ-5D model due to its low reliability. These results are useful for researchers and clinicians involved in chronic pain populations because questionnaires' properties determine their discriminating ability in patient status assessment.

Machine learning suggests sleep as a core factor in chronic pain

Patients with chronic pain have complex pain profiles and associated problems. Subgroup analysis can help identify key problems. We used a data-based approach to define pain phenotypes and their most relevant associated problems in 320 patients undergoing tertiary pain management. Unsupervised machine learning analysis of parameters "pain intensity," "number of pain areas," "pain duration," "activity pain interference," and "affective pain interference," implemented as emergent self-organizing maps, identified 3 patient phenotype clusters. Supervised analyses, implemented as different types of decision rules, identified "affective pain interference" and the "number of pain areas" as most relevant for cluster assignment. These appeared 698 and 637 times, respectively, in 1000 cross-validation runs among the most relevant characteristics in an item categorization approach in a computed ABC analysis. Cluster assignment was achieved with a median balanced accuracy of 79.9%, a sensitivity of 74.1%, and a specificity of 87.7%. In addition, among 59 demographic, pain etiology, comorbidity, lifestyle, psychological, and treatment-related variables, sleep problems appeared 638 and 439 times among the most important characteristics in 1000 cross-validation runs where patients were assigned to the 2 extreme pain phenotype clusters. Also important were the parameters "fear of pain," "self-rated poor health," and "systolic blood pressure." Decision trees trained with this information assigned patients to the extreme pain phenotype with an accuracy of 67%. Machine learning suggested sleep problems as key factors in the most difficult pain presentations, therefore deserving priority in the treatment of chronic pain.

Adults' Self-Management of Chronic Cancer and Noncancer Pain in People with and Without Cognitive Impairment: A Concept Analysis

AIM

To report a concept analysis of adult self-management of chronic pain.

BACKGROUND

Self-management of chronic pain has received increasing attention in the clinical research literature. Although with only limited conceptual work. Despite the pervasiveness of pain in adults, there has been a lack of conceptual work to elucidate meaning of adult's self-management of chronic pain.

DESIGN

Concept Analysis.

METHOD

Rodgers (2000) evolutionary approach of concept analysis was used to systematically analyze 44 articles from different databases. Only 12 articles used the concept of chronic pain self-management. Data were extracted using standardized forms and analyzed using thematic analysis.

RESULTS

This concept analysis identified six attributes of adult self-management of chronic pain: (1) multimodal interventions; (2) patient-provider relationship; (3) goal setting; (4) decision making; (5) resource utilization; and (6) chronic pain problem solving.

The Context Matters: A Retrospective Analysis of Life Stage at Chronic Pain Onset in Relation to Pain Characteristics and Psychosocial Outcomes

BACKGROUND

Developmental life stage at chronic pain onset differs among chronic pain patients. Although pain affects multiple life domains, it is unknown whether the timing of chronic pain onset relates to pain characteristics and psychosocial outcomes. The purpose of this retrospective study was to investigate differences in pain characteristics and psychosocial outcomes in patients at different developmental life stages at chronic pain onset.

METHODS

Cross-sectional baseline data from the Swedish Quality Registry for Pain Rehabilitation (2009 to 2016) were used, selecting the middle-aged patients (45-65 years, n=6225) reporting chronic nonmalignant pain. Patients were categorized into three groups, depending on their developmental life stage at chronic pain onset: early onset (age ≤30 years), intermediate onset (age 31-45 years), and late onset (age ≥46 years). Pain characteristics and psychosocial outcomes were assessed with validated self-reported measures.

RESULTS

One-way MANCOVA indicated differences in number of pain locations and psychosocial outcomes among the groups. Post hoc analysis showed differences in the trends for how groups differed on outcome domains. Overall, patients with earlier chronic pain onset showed significantly poorer psychosocial outcomes and more spreading of pain.

CONCLUSION

Developmental life stage at chronic pain onset is associated with different pain outcomes. Pain onset early in life is linked to worse outcomes in multiple domains, pointing to a need for identifying these patients early.

Outcome Measures for Functional Neurological Disorder: A Review of the Theoretical Complexities

The development and selection of optimal outcome measures is increasingly recognized as a key component of evidence-based medicine, particularly the need for the development of a standardized set of measures for use in clinical trials. This process is particularly complex for functional neurological disorder (FND) for several reasons. FND can present with a wide range of symptoms that resemble the full spectrum of other neurological disorders. Additional physical (e.g., pain, fatigue) and psychological (e.g., depression, anxiety) symptoms are commonly associated with FND, which also can be highly disabling with implications for prognosis, and warrant concurrent assessment, despite an unclear etiological relationship with FND. Furthermore, several unique clinical aspects of FND make it likely that the usual prioritization of "objective" (or clinician-rated) over "subjective" (or patient-rated) measures might not be appropriate. Self-report measures may be more clinically meaningful in this patient population. Despite being a common and disabling disorder, there has been little research into outcome measures in FND, and to date trials have largely used measures designed for the assessment of other disorders. An international FND Core Outcome Measure group (FND-COM) has been established to develop a consensus battery of outcomes for FND: a "core outcome set." In this perspective article, the authors reviewed the process of outcome measure development and selection before considering the specific features of FND affecting the development of a core outcome set, as well as a research agenda to optimize outcome measurement in this complex neuropsychiatric disorder.

Interpretation of cluster structures in pain-related phenotype data using explainable artificial intelligence (XAI)

BACKGROUND

In pain research and clinics, it is common practice to subgroup subjects according to shared pain characteristics. This is often achieved by computer-aided clustering. In response to a recent EU recommendation that computer-aided decision making should be transparent, we propose an approach that uses machine learning to provide (1) an understandable interpretation of a cluster structure to (2) enable a transparent decision process about why a person concerned is placed in a particular cluster.

METHODS

Comprehensibility was achieved by transforming the interpretation problem into a classification problem: A sub-symbolic algorithm was used to estimate the importance of each pain measure for cluster assignment, followed by an item categorization technique to select the relevant variables. Subsequently, a symbolic algorithm as explainable artificial intelligence (XAI) provided understandable rules of cluster assignment. The approach was tested using 100-fold cross-validation.

RESULTS

The importance of the variables of the data set (6 pain-related characteristics of 82 healthy subjects) changed with the clustering scenarios. The highest median accuracy was achieved by sub-symbolic classifiers. A generalized post-hoc interpretation of clustering strategies of the model led to a loss of median accuracy. XAI models were able to interpret the cluster structure almost as correctly, but with a slight loss of accuracy.

CONCLUSIONS

Assessing the variables importance in clustering is important for understanding any cluster structure. XAI models are able to provide a human-understandable interpretation of the cluster structure. Model selection must be adapted individually to the clustering problem. The advantage of comprehensibility comes at an expense of accuracy.

Telemonitoring in Chronic Pain Management Using Smartphone Apps: A Randomized Controlled Trial Comparing Usual Assessment against App-Based Monitoring with and without Clinical Alarms

BACKGROUND

The usefulness of mHealth in helping to target face-to-face interventions for chronic pain more effectively remains unclear. In the present study, we aim to test whether the Pain Monitor mobile phone application (app) is well accepted by clinicians, and can help improve existent medical treatments for patients with chronic musculoskeletal pain. Regarding this last goal, we compared three treatment conditions, namely usual treatment, usual treatment with an app without alarms and usual treatment with an app with alarms. All treatments lasted one month. The three treatments were compared for all outcomes, i.e., pain severity and interference, fatigue, depressed mood, anxiety and anger.

METHODS

In this randomized controlled trial, the usual monitoring method (i.e., onsite; n = 44) was compared with daily ecological momentary assessment using the Pain Monitor app-both with (n = 43) and without alarms (n = 45). Alarms were sent to the clinicians in the presence of pre-established undesired clinical events and could be used to make treatment adjustments throughout the one-month study.

RESULTS

With the exception of anger, clinically significant changes (CSC; 30% improvement) were greater in the app + alarm condition across outcomes (e.g., 43.6% of patients experienced a CSC in depressed mood in the app + alarm condition, which occurred in less than 29% of patients in the other groups). The clinicians were willing to use the app, especially the version with alarms.

CONCLUSIONS

The use of apps may have some benefits in individual health care, especially when using alarms to tailor treatments.