The Potential of Treatment Matching for Subgroups of Patients With Chronic Pain

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.

Investigating mortality salience as a potential causal influence and moderator of responses to laboratory pain

Background

Because pain can have profound ramifications for quality of life and daily functioning, understanding nuances in the interplay of psychosocial experiences with pain perception is vital for effective pain management. In separate lines of research, pain resilience and mortality salience have emerged as potentially important psychological correlates of reduced pain severity and increased tolerance of pain. However, to date, there has been a paucity of research examining potentially interactive effects of these factors on pain perception. To address this gap, the present experiment investigated mortality salience as a causal influence on tolerance of laboratory pain and a moderator of associations between pain resilience and pain tolerance within a Chinese sample.

Methods

Participants were healthy young Chinese adults (86 women, 84 men) who first completed a brief initial cold pressor test (CPT) followed by measures of demographics and pain resilience. Subsequently, participants randomly assigned to a mortality salience (MS) condition completed two open-ended essay questions in which they wrote about their death as well as a death anxiety scale while those randomly assigned to a control condition completed analogous tasks about watching television. Finally, all participants engaged in a delay task and a second CPT designed to measure post-manipulation pain tolerance and subjective pain intensity levels.

Results

MS condition cohorts showed greater pain tolerance than controls on the post-manipulation CPT, though pain intensity levels did not differ between groups. Moderator analyses indicated that the relationship between the behavior perseverance facet of pain resilience and pain tolerance was significantly stronger among MS condition participants than controls.

Conclusions

This experiment is the first to document potential causal effects of MS on pain tolerance and Ms as a moderator of the association between self-reported behavior perseverance and behavioral pain tolerance. Findings provide foundations for extensions within clinical pain samples.

IUPHAR review: Navigating the role of preclinical models in pain research

Chronic pain is a complex and challenging medical condition that affects millions of people worldwide. Understanding the underlying mechanisms of chronic pain is a key goal of preclinical pain research so that more effective treatment strategies can be developed. In this review, we explore nociception, pain, and the multifaceted factors that lead to chronic pain by focusing on preclinical models. We provide a detailed look into inflammatory and neuropathic pain models and discuss the most used animal models for studying the mechanisms behind these conditions. Additionally, we emphasize the vital role of these preclinical models in developing new pain-relief drugs, focusing on biologics and the therapeutic potential of NMDA and cannabinoid receptor antagonists. We also discuss the challenges of TRPV1 modulation for pain treatment, the clinical failures of neurokinin (NK)- 1 receptor antagonists, and the partial success story of Ziconotide to provide valuable lessons for preclinical pain models. Finally, we highlight the overall success and limitations of current treatments for chronic pain while providing critical insights into the development of more effective therapies to alleviate the burden of chronic pain.

Hierarchical Cluster Analysis Based on Clinical and Neuropsychological Symptoms Reveals Distinct Subgroups in Fibromyalgia: A Population-Based Cohort Study

Fibromyalgia (FM) is a condition characterized by musculoskeletal pain and multiple comorbidities. Our study aimed to identify four clusters of FM patients according to their core clinical symptoms and neuropsychological comorbidities to identify possible therapeutic targets in the condition. We performed a population-based cohort study on 251 adult FM patients referred to primary care according to the 2010 ACR case criteria. Patients were aggregated in clusters by a K-medians hierarchical cluster analysis based on physical and emotional symptoms and neuropsychological variables. Four different clusters were identified in the FM population. Global cluster analysis reported a four-cluster profile (cluster 1: pain, fatigue, poorer sleep quality, stiffness, anxiety/depression and disability at work; cluster 2: injustice, catastrophizing, positive affect and negative affect; cluster 3: mindfulness and acceptance; and cluster 4: surrender). The second analysis on clinical symptoms revealed three distinct subgroups (cluster 1: fatigue, poorer sleep quality, stiffness and difficulties at work; cluster 2: pain; and cluster 3: anxiety and depression). The third analysis of neuropsychological variables provided two opposed subgroups (cluster 1: those with high scores in surrender, injustice, catastrophizing and negative affect, and cluster 2: those with high scores in acceptance, positive affect and mindfulness). These empirical results support models that assume an interaction between neurobiological, psychological and social factors beyond the classical biomedical model. A detailed assessment of such risk and protective factors is critical to differentiate FM subtypes, allowing for further identification of their specific needs and designing tailored personalized therapeutic interventions.

Virtual Human-Delivered Interviews for Patients With Chronic Pain: Feasibility, Acceptability, and a Pilot Randomized Trial of Standard Medical, Psychosocial, and Educational Interviews

OBJECTIVE

Seminal advances in virtual human (VH) technology have introduced highly interactive, computer-animated VH interviewers. Their utility for aiding in chronic pain care is unknown. We developed three interactive telehealth VH interviews-a standard pain-focused, a psychosocial risk factor, and a pain psychology and neuroscience educational interview. We then conducted a preliminary investigation of their feasibility, acceptability, and efficacy. We also experimentally compared a human and a computer-generated VH voice.

METHODS

Patients ( N = 94, age = 22-78 years) with chronic musculoskeletal pain were randomly assigned to the standard ( n = 31), psychosocial ( n = 34), or educational ( n = 29) VH interview and one of the two VH voices. Acceptability ratings included patient satisfaction and expectations/evaluations of the VH interview. Outcomes assessed at baseline and about 1-month postinterview were pain intensity, interference, emotional distress, pain catastrophizing, and readiness for pain self-management. Linear mixed-effects models were used to test between- and within-condition effects.

RESULTS

Acceptability ratings showed that satisfaction with the VH and telehealth format was generally high, with no condition differences. Study attrition was low ( n = 5). Intent-to-treat-analyses showed that, compared with the standard interview, the psychosocial interview yielded a significantly greater reduction in pain interference ( p = .049, d = 0.43) and a marginally greater reduction in pain intensity ( p = .054, d = 0.36), whereas the educational interview led to a marginally greater yet nonsignificant increase in readiness for change ( p = .095, d = 0.24), as well as several significant improvements within-condition. Results did not differ by VH voice.

CONCLUSIONS

Interactive VH interviewers hold promise for improving chronic pain care, including probing for psychosocial risk factors and providing pain-related education.

Mindfulness meditation use in chronic pain treatment in rural Australia: Pitfalls and potential - A case report

Mindfulness is a state of awareness characterized by open and non-judgmental recognition of thoughts and sensations and an ability to resist the usual wandering of an individual's attention. Usually achieved by meditation, mindfulness is recognized as a treatment for chronic pain. Evidence, thus far, has been characterized by poor quality trials and mixed results, but a growing body of research is further investigating its effectiveness. Despite inconclusive evidence, the inherent difficulties of mindfulness research, and problems of accessibility in rural settings, mindfulness meditation is an emerging treatment strategy for many chronic pain patients. This report presents the case of a patient admitted to a rural hospital in New South Wales, whose quality of life was severely impacted by chronic pain.

Identifying Chronic Pain Subgroups in Pediatric Sickle Cell Disease: A Cluster-Analytic Approach

OBJECTIVES

Youth with sickle cell disease (SCD) and chronic pain, defined in this study as pain on most days for 3 months, experience variability in daily pain and physical and psychosocial functioning. This study aimed to (1) empirically derive chronic pain subgroups based on pain characteristics among youth with chronic SCD pain; and (2) investigate derived subgroups for differences in sociodemographics, clinical characteristics, and psychosocial and functional outcomes.

MATERIALS AND METHODS

Youth with chronic SCD pain (n=62, Mage =13.9, SD=2.5, 10 to 18 y; 58% female, 60% HbSS) completed a battery of questionnaires. Clinical characteristics (eg, medications, treatments) and health care utilization were abstracted from electronic medical records. Hierarchical cluster analysis informed the number of clusters at the patient level. k-means cluster analysis used multidimensional pain assessment to identify and assign patients to clusters.

RESULTS

Cluster 1 (n=35; Moderate Frequency, Moderate Pain) demonstrated significantly lower worst pain intensity, number of pain days per month, number of body sites affected by pain, and pain quality ratings. Cluster 2 (n=27; Almost Daily, High Pain) reported high ratings of worst pain intensity, almost daily to daily pain, greater number of body sites affected by pain, and higher ratings of pain quality (all P 's <0.05). There were no differences between subgroups by sociodemographics, clinical characteristics, or health care utilization. The Almost Daily, High Pain subgroup reported significantly higher pain interference, depressive symptoms, and pain catastrophizing than the Moderate Frequency, Moderate Pain subgroup.

DISCUSSION

Identifying chronic SCD pain subgroups may inform tailored assessment and intervention to mitigate poor pain and functional outcomes.

Predictors of Outcomes Following Interdisciplinary Acceptance and Commitment Therapy for Chronic Pain: Profiling Psychological Flexibility

Background

Growing evidence demonstrates the benefit of acceptance and commitment therapy (ACT) for people with chronic pain. However, there remain people with chronic pain who do not benefit from ACT, and predicting treatment response is difficult.

Aims

This aim of this study was to investigate if baseline psychological flexibility (PF) profiles predict responses to an ACT‐based pain management programme.

Methods

Data from 415 participants attending an interdisciplinary pain management programme were included. Participants completed measures of PF processes and outcomes pre‐ and post‐treatment. Latent profile analysis was used to identify subgroups of participants based on their baseline PF scores. ANOVAs were conducted to compare subgroups of participants on outcome variables at baseline, and changes from pre‐ to post‐treatment.

Results

Three subgroups of participants were identified: (a) low PF, (b) low openness and (c) high awareness and action. The three subgroups significantly differed on all outcome measures at pre‐treatment, supporting the clinical relevance of these PF profiles. However, participants with different baseline PF profiles did not appear to differ in terms of changes in outcome variables.

Conclusions

People with chronic pain demonstrate different PF profiles, but appear to respond to ACT similarly regardless of these profiles. Future studies with a more individualized focus are needed to further understand which components of ACT work for whom on which outcome and how.

Significance

There remain people with chronic pain who do not benefit from acceptance and commitment therapy (ACT), and predicting treatment response is difficult. This is the first study to identify psychological flexibility (PF) profiles along multiple PF processes using latent class analysis, and the first longitudinal study to investigate PF profiles in relation to outcomes in ACT for chronic pain. The findings contribute to the understanding of theoretically consistent predictors of outcomes in ACT, which in turn can inform treatment development.

Development and evaluation of the MAINTAIN instrument, selecting patients suitable for secondary or tertiary preventive manual care: the Nordic maintenance care program

Background

Chiropractic maintenance care (MC) has been found to be effective for patients classified as dysfunctional by the West Haven-Yale Multidimensional Pain Inventory (MPI). Although displaying good psychometric properties, the instrument was not designed to be used in clinical practice to screen patients for stratified care pathways. The aim was to develop a brief clinical instrument with the intent of identifying dysfunctional patients with acceptable diagnostic accuracy.

Methods

Data from 249 patients with a complete MPI dataset from a randomized clinical trial that investigated the effect and cost-effectiveness of MC with a 12-month follow-up was used in this cross-sectional analysis. A brief screening instrument was developed to identify dysfunctional patients, with a summary measure. Different cut-offs were considered with regards to diagnostic accuracy using the original instrument’s classification of dysfunctional patients as a reference. Very good diagnostic accuracy was defined as an area under the curve (AUC) metric between 0.8 and 0.9. The instrument was then externally validated in 3 other existing datasets to assess model transportability across populations and medical settings.

Results

Using an explorative approach, the MAINTAIN instrument with 10 questions (0–6 Likert responses) capturing 5 dimensions (pain severity, interference, life control, affective distress, and support) was developed, generating an algorithm-based score ranging from − 12 to 48. Reporting a MAINTAIN score of 18 or higher, 146 out of the 249 patients were classified as dysfunctional with 95.8% sensitivity and 64.3% specificity. At a score of 22 or higher, 109/249 were classified as dysfunctional with 81.1% sensitivity and 79.2% specificity. AUC was estimated to 0.87 (95% CI 0.83, 0.92) and Youden’s index was highest (0.70) at a score of 20. The diagnostic accuracy was similar and high across populations with minor differences in optimal thresholds for identifying dysfunctional individuals.

Conclusion

The MAINTAIN instrument has very good diagnostic accuracy with regards to identifying dysfunctional patients and may be used as a decision aid in clinical practice. By using 2 thresholds, patients can be categorized into “low probability (− 12 to 17)”, “moderate probability (18 to 21)”, and “high probability (22 to 48)” of having a good outcome from maintenance care for low back pain.

Trial registration

Clinical trials.gov; NCT01539863; registered February 28, 2012; https://clinicaltrials.gov/ct2/show/NCT01539863.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12998-022-00424-6.

A Randomized controlled trial of the Sources of Meaning Card Method: A new meaning-oriented approach predicts depression, anxiety, pain acceptance, and crisis of meaning in chronic pain patients

OBJECTIVE

Although considered the first-line psychological treatment of chronic pain, cognitive behavioural therapy has recently been criticized as being too limited, insufficient, and sometimes ineffective in the treatment of chronic pain patients. Moreover, important existential perspectives are sparsely or not at all integrated into CBT. We therefore propose to complement chronic pain treatment with a meaning-based intervention, the Sources of Meaning Card Method (SoMeCaM). This study tested its efficacy.

DESIGN

A randomized controlled trial was conducted with 42 chronic pain patients, comparing an intervention group (standard care and participation in the SoMeCaM, a meaning-oriented approach) with a control group (standard care). We evaluated both groups at baseline, 1 (t1) and 2 months (t2) after the intervention. The primary outcome assessed was pain acceptance, while depression, anxiety, pain intensity, pain medication, satisfaction with life, meaningfulness, and crisis of meaning were examined as secondary outcomes.

RESULTS

Comparisons within and between groups showed significant treatment effects at t1. Higher increases in pain acceptance and decreases in anxiety, depression and crisis of meaning were observed in the intervention group. Improvements in pain acceptance and anxiety persisted until t2, when pain intensity was also lower. Effect sizes at t2 were medium to large.

CONCLUSION

Our preliminary work demonstrates the importance of the existential perspective in chronic pain therapy.

[Results of a pilot study on the role of therapy expectation in interdisciplinary multimodal pain therapy for chronic back pain]

Hintergrund

Chronische Rückenschmerzen sind eine schwerwiegende und global sehr häufig auftretende Erkrankung mit enormen persönlichen sowie sozioökonomischen Auswirkungen. Die interdisziplinäre multimodale Schmerztherapie (IMST) ist eines der wenigen evidenzbasierten Behandlungsverfahren für chronische Schmerzen. Obwohl bekannt ist, dass Schmerzen sowie deren Chronifizierung und Behandlung von den persönlichen Erwartungen der Patienten beeinflusst werden, gibt es wenige etablierte Interventionen oder Richtlinien für eine aktive Modulation dieses Effekts.

Ziel der Arbeit

Wir möchten mit dieser Arbeit die Rolle der Erwartung als Prädiktor für Schmerzen sowie schmerzbezogene Beeinträchtigung in der klinischen Praxis verdeutlichen und präsentieren hierzu beispielhaft explorative Pilotdaten einer Beobachtungskohorte unserer Klinik.

Material und Methoden

Die Untersuchung zeigt erste Daten einer prospektiven longitudinalen Beobachtungsstudie bestehend aus bis zu 41 Patienten mit chronischen Rückenschmerzen, die im Setting einer IMST am Essener Rückenschmerz-Zentrum behandelt wurden. Es wurden Daten zum Zeitpunkt der Aufnahme (T0) und der Entlassung (T1) sowie drei Monate nach Therapieende (T2) erhoben. Primäre Endpunkte waren die Schmerzintensität und die Schmerzbeeinträchtigung. Zusätzlich erfassten wir die Therapieerwartung zum Zeitpunkt der Aufnahme als möglichen Prädiktor. Die Bedeutung der vor der Therapie erhobenen Therapieerwartung wurde mittels linearer Regression erfasst.

Ergebnisse

Die IMST führte zu einer signifikanten Besserung in Bezug auf die Schmerzintensität und -beeinträchtigung. Der Effekt auf die Schmerzintensität war über den Zeitraum von drei Monaten nach Therapieende anhaltend und die Beeinträchtigung sank in diesem Zeitraum weiter signifikant.

Diskussion

Erwartung war ein signifikanter Prädiktor für die Abnahme der Schmerzintensität und erklärte ca. 15 % der Varianz. In der klinischen Praxis sollten daher valide Methoden etabliert werden, negative Erwartungen zu reduzieren und positive Erwartungen zu fördern.

Can Acupuncture Improve Chronic Spinal Pain? A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVE

To investigate the effect and safety of acupuncture for the treatment of chronic spinal pain.

METHODS

MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, the WHO Clinical Trial Registry, and the US National Library of Medicine clinical trial registry were searched from January 1, 2000, to November 1, 2019. Randomized controlled trials (RCTs) involving patients with chronic spinal pain treated by acupuncture versus sham acupuncture, no treatment, or another treatment were included.

RESULTS

Data was extracted from 22 RCTs including 2588 patients. Pooled analysis revealed that acupuncture can reduce chronic spinal pain compared to sham acupuncture (weighted mean difference [WMD] -12.05, 95% confidence interval [CI] -15.86 to -8.24), mediation control (WMD -18.27, 95% CI -28.18 to -8.37), usual care control (WMD -9.57, 95% CI -13.48 to -9.44), and no treatment control (WMD -17.10, 95% CI -24.83 to -9.37). In terms of functional disability, acupuncture can improve physical function at immediate-term follow-up (standardized mean difference [SMD] -1.74, 95% CI -2.04 to -1.44), short-term follow-up (SMD -0.89, 95% CI -1.15 to -0.62), and long-term follow-up (SMD -1.25, 95% CI -1.48 to -1.03).

CONCLUSION

In summary, compared to no treatment, sham acupuncture, or conventional therapy such as medication, massage, and physical exercise, acupuncture has a significantly superior effect on the reduction in chronic spinal pain and function improvement. Acupuncture might be an effective treatment for patients with chronic spinal pain and it is a safe therapy.

The nordic maintenance care program: patient experience of maintenance care-a qualitative study

Background

Low back pain is one of the major causes of disability world-wide. Most back pain sufferers experience pain that is recurrent or persistent, making management of this condition a priority. In a series of previous studies, chiropractic maintenance care has been found to be an effective way of reducing the number of days with pain, particularly for patients with a certain psychological profile. However, little is known about patients’ experience of this kind of management plan. This study aimed to explore patient experiences and preferences by looking at barriers to and facilitators of engaging in and maintaining a care plan, and to contrast the data using psychological sub-groups.

Methods

In this qualitative study we performed semi-structured interviews with 24 patients who had previously participated in a Swedish trial evaluating maintenance care. They were purposefully selected to obtain richness, variation and breadth of data. The data were analyzed using inductive qualitative manifest and latent content analysis. We used the theory of planned behavior to deepen our understanding of the constructed themes.

Results

The analysis resulted in two overarching dimensions: “when maintenance care is of high value” and “when maintenance care is of low value”. Four factors were jointly identified as obstacles to maintenance care by patients in all the psychological subgroups. These factors were: Cost demanding, A sense of low value, Perceived as unavailable and Fear of treatment. The one factor seen as facilitating maintenance care by patients in all the subgroups was Care that is patient-centered.

Conclusions

The findings reveal a variance of both positive and negative experiences of MC in the psychological subgroups. These findings can deepen our understanding of how patients experience MC and can help clinicians to understand when patients might regard maintenance care as being of high value.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12998-021-00388-z.

Design and methods of the Care Management for the Effective Use of Opioids (CAMEO) trial

Low back pain is the most common pain condition seen in primary care, with the most common treatment being analgesic medications, including opioids. A dramatic increase in opioid prescriptions for low back pain over the past few decades has led to increased non-medical use and opioid overdose deaths. Cognitive behavioral therapy (CBT) for chronic pain is an evidence-based non-pharmacological treatment for pain with demonstrated efficacy when delivered using collaborative care models. No previous studies have tested CBT compared to analgesic optimization that includes opioid management in primary care. This paper describes the study design and methods of the CAre Management for the Effective use of Opioids (CAMEO) trial, a 2-arm, randomized comparative effectiveness trial in seven primary care clinics. CAMEO enrolled 261 primary care veterans with chronic (6 months or longer) low back pain of at least moderate severity who were receiving long-term opioid therapy and randomized them to either nurse care management focused on analgesic treatment and optimization (MED) or cognitive behavioral therapy (CBT). All subjects undergo comprehensive outcome assessments at baseline, 3, 6, 9, and 12 months by interviewers blinded to treatment assignment. The primary outcome is pain severity and interference, measured by the Brief Pain Inventory (BPI) total score. Secondary outcomes include health-related quality of life, fatigue, sleep, functional improvement, pain disability, pain beliefs, alcohol and opioid problems, depression, anxiety, and stress.

Endurance and avoidance response patterns in pain patients: Application of action control theory in pain research

BACKGROUND

Identifying pain-related response patterns and understanding functional mechanisms of symptom formation and recovery are important for improving treatment.

OBJECTIVES

We aimed to replicate pain-related avoidance-endurance response patterns associated with the Fear-Avoidance Model, and its extension, the Avoidance-Endurance Model, and examined their differences in secondary measures of stress, action control (i.e., dispositional action vs. state orientation), coping, and health.

METHODS

Latent profile analysis (LPA) was conducted on self-report data from 536 patients with chronic non-specific low back pain at the beginning of an inpatient rehabilitation program. Measures of stress (i.e., pain, life stress) and action control were analyzed as covariates regarding their influence on the formation of different pain response profiles. Measures of coping and health were examined as dependent variables.

RESULTS

Partially in line with our assumptions, we found three pain response profiles of distress-avoidance, eustress-endurance, and low-endurance responses that are depending on the level of perceived stress and action control. Distress-avoidance responders emerged as the most burdened, dysfunctional patient group concerning measures of stress, action control, maladaptive coping, and health. Eustress-endurance responders showed one of the highest levels of action versus state orientation, as well as the highest levels of adaptive coping and physical activity. Low-endurance responders reported lower levels of stress as well as equal levels of action versus state orientation, maladaptive coping, and health compared to eustress-endurance responders; however, equally low levels of adaptive coping and physical activity compared to distress-avoidance responders.

CONCLUSIONS

Apart from the partially supported assumptions of the Fear-Avoidance and Avoidance-Endurance Model, perceived stress and dispositional action versus state orientation may play a crucial role in the formation of pain-related avoidance-endurance response patterns that vary in degree of adaptiveness. Results suggest tailoring interventions based on behavioral and functional analysis of pain responses in order to more effectively improve patients quality of life.

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.

Patterns of Approach to Activity in 851 Patients With Severe Chronic Pain: Translation and Preliminary Validation of the 9-item Avoidance-Endurance Fast-Screen (AEFS) Into Danish

OBJECTIVES

The Avoidance-Endurance Fast-Screen (AEFS) is a 9-item self-report questionnaire that classifies patients with back pain into 4 activity-related subgroups, based on the Avoidance-Endurance Model of pain. The objective of this study was to translate the AEFS into Danish and investigate its discriminative abilities in a large, diverse patient sample.

MATERIALS AND METHODS

A total of 851 specialist care-seeking patients with severe chronic pain conditions participated in this cross-sectional study. Participants were categorized as showing a "distress-endurance" (DER), "eustress-endurance" (EER), "fear-avoidance" (FAR), or "adaptive" (AR) pattern. Principal component analysis reduced a large number of psychological variables beforehand. Construct and outcome-based validity were explored using multivariate analysis of variance.

RESULTS

Of the participants, 33.6% were categorized as DER, 29.4% as EER, 22% as FAR, and 15% as adaptive. Principal component analysis showed the factors activity-related pain behavior, affective distress, and dysfunctional pain thoughts. The AEFS-DK discriminated all 4 subgroups in terms or their pain behavior with EER>DER>AR>FAR. FAR showed less moderate/vigorous activity than DER and EER and more sedentary time than EER. DER and FAR showed higher affective distress, dysfunctional pain thoughts, and poorer outcomes than AR and EER.

CONCLUSION

The results indicate good construct validity of the AEFS-DK discriminating the 4 avoidance-endurance model-related subgroups with respect to approach to activity behavior, psychological variables, and reported physical activity. Concerning outcome-based validity, 2 subgroups DER/FAR and AR/EER could be distinguished with inconclusive results for the eustress-endurance subgroup. Future studies are warranted using longitudinal research designs investigating whether AEFS subgroups differ in terms of treatment effects and long-term prognosis.

Norwegian Psychomotor Physiotherapy versus Cognitive Patient Education and active physiotherapy-A randomized controlled trial

BACKGROUND AND PURPOSE

Norwegian Psychomotor Physiotherapy (NPMP) has been an established treatment approach for more than 50 years, mostly in the Scandinavian countries, usually applied to patients with widespread and long-lasting musculoskeletal pain and/or psychosomatic disorders. Few studies have investigated the outcomes of NPMP, and no randomized clinical trials (RCT) with a comparing treatment group have systematically been tried out on individuals.

METHODS

This is a pragmatic, single-blinded RCT where 128 participants with long-lasting widespread musculoskeletal pain and/or pain located to the neck and shoulders were block randomized to NPMP or Cognitive Patient Education combined with active individualized physiotherapy (COPE-PT). Intention-to-treat with linear mixed models were used to estimate the group differences in treatment effects. The outcomes at 3, 6, and 12 months follow-up were pain intensity, function, anxiety and depression, quality of life, sleep, fear of movement, and subjective health complaints. Risk profile (Örebro) was examined at 3 and 6 months. All participants underwent physical tests at baseline and 6 months.

RESULTS

One-year data were available for 66.4% of the original participants. Calculated with intention-to-treat analysis, at 3 months statistically significant differences were found in favor of COPE-PT for pain, anxiety and depression, quality of life-physical dimension, risk profile and fear of movement. At 6 months, statistically significant differences in favor of COPE-PT were found for anxiety and depression, and sleep. At 12 months, the improvements were still statistically significant for anxiety, depression and sleep. Both groups improved, but no statistically significant differences were found between the groups on the physical tests at 6 months.

CONCLUSIONS

COPE-PT, which is targeted towards pain-coping and increasing activity, contribute to more improvements than NPMP.

Pain coping skills training for African Americans with osteoarthritis: results of a randomized controlled trial

African Americans bear a disproportionate burden of osteoarthritis (OA), but they have been underrepresented in trials of behavioral interventions for pain. This trial examined a culturally tailored pain coping skills training (CST) program, compared to a wait list control group, among 248 African Americans with knee or hip OA. The pain CST program involved 11 telephone-based sessions over 3 months. Outcomes were assessed at baseline, 3 months (primary), and 9 months, and included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale (primary outcome), WOMAC total score and function subscale, PROMIS Pain Interference, Short-Form 12 Mental and Physical Composite Subscales, Coping Strategies Questionnaire-Total Coping Attempts, Pain Catastrophizing Scale, Patient Health Questionnaire-8, Arthritis Self-Efficacy Scale, and Patient Global Impression of Arthritis Symptom Change. Linear mixed models were fit for all outcomes. There were no significant between-group differences in WOMAC pain score at 3 months (-0.63 [95% confidence interval -1.45, 0.18]; P = 0.128) or 9 months (-0.84 [95% confidence interval -1.73, 0.06]; P = 0.068). Among secondary outcomes, at 3 months, there were significant differences, in favor of the CST group, for Coping Strategies Questionnaire Total Coping Attempts, Pain Catastrophizing Scale, Arthritis Self-Efficacy, and Patient Global Impression of Arthritis Symptom Change (P < 0.01). Coping Strategies Questionnaire Total Coping Attempts, Arthritis Self-Efficacy, and Patient Global Assessment Change were also significantly improved at 9 months in the CST group, compared with wait list (P < 0.01). The culturally tailored pain CST program did not significantly reduce pain severity but did improve key measures of pain coping and perceived ability to manage pain among African Americans with OA.

Serious Gaming During Multidisciplinary Rehabilitation for Patients With Chronic Pain or Fatigue Symptoms: Mixed Methods Design of a Realist Process Evaluation

BACKGROUND

Serious gaming could support patients in learning to cope with chronic pain or functional somatic syndromes and reduce symptom burdens.

OBJECTIVE

To realize this potential, insight is needed into how, why, for whom, and when it works in actual treatment circumstances.

METHODS

Following a realist approach, process evaluations were performed before, during, and after a two-armed, natural quasi-experiment (n=275). A group of patients with interfering chronic pain or fatigue symptoms received a short additional blended mindfulness-based serious gaming intervention during a multidisciplinary rehabilitation program. A control group only received the regular rehabilitation program. During two sessions before and one session after the experiment, expectations about serious gaming processes were discussed in focus groups with local care providers, implementers, and experts. Patients participated in a survey (n=114) and in semistructured interviews (n=10). The qualitative data were used to develop tentative expectations about aspects of serious gaming that, in certain patients and circumstances, trigger mechanisms of learning and health outcome change. Hypotheses about indicative quantitative data patterns for tentative expectations were formulated before inspecting, describing, and analyzing-with regression models-routinely collected clinical outcome data. An updated program theory was formulated after mixing the qualitative and quantitative results.

RESULTS

Qualitative data showed that a subset of patients perceived improvement of their self-awareness in moments of daily social interactions. These results were explained by patients, who played the serious game LAKA, as a "confrontation with yourself," which reflected self-discrepancies. Important characteristics of serious gaming in the study's context included innovation factors of relative advantage with experiential learning opportunity, compatibility with the treatment approach, and the limited flexibility in regard to patient preferences. Perceived patient factors included age and style of coping with stress or pain. Learning perceptions could also depend on care provider role-taking and the planning and facilitating (ie, local organization) of serious gaming introduction and feedback sessions in small groups of patients. Quantitative data showed very small average differences between the study groups in self-reported depression, pain, and fatigue changes (-.07<beta<-.17, all 95% CI upper bounds <0), which were mediated by small group differences in mindfulness (beta=.26, 95% CI .02-.51). Mindfulness changes were positively associated with patient involvement in serious gaming (n=114, beta=.36, P=.001). Acceptance of serious gaming was lower in older patients. Average health outcome changes went up to a medium size in patients that reported lower active coping with stress and lower pain coping before serious gaming. Mindfulness changes and gaming acceptance perceptions covaried with group structure and immediate feedback sessions after serious gaming.

CONCLUSIONS

This study developed transferable insight into how and why serious gaming can facilitate additional learning about coping in order to reduce burdens of chronic pain or fatigue symptoms in certain patients and in actual treatment circumstances. Future studies are needed to continue the development of this fallible theory. Such research will further support decisions about using, designing, allocating, and tailoring serious gaming to optimize important patient health benefits.

TRIAL REGISTRATION

Netherlands Trial Register NTR6020; https://www.trialregister.nl/trial/5754.

Psychological Subgrouping to Assess the Risk for the Development or Maintenance of Chronic Musculoskeletal Pain: Is This the Way Forward?

BACKGROUND

Because musculoskeletal pain problems are so prevalent, new methods of evaluating and treating patients are needed to increase effectiveness. Subgrouping is a method wherein patients are classified into defined groups on the basis of psychosocial factors with the expectation of more specific and tailored treatments can be prescribed for them. For those seeking care for a new episode, the risk of developing chronic pain-related disability is assessed, whereas, for those with existing pain, the risk for the maintenance of the chronic pain problem is evaluated.

AIM

The purpose of this narrative review is to examine how patients are classified into subgroups with regard to methods of evaluation and to ascertain whether subgrouping actually facilitates treatment.

RESULTS

For the development of disability, screening tools, for example, the Örebro Musculoskeletal Pain Screening Questionnaire, accurately stratify patients into groups (eg, high, medium, low risk) that predict future pain-related work disability. In addition, several studies show that treatments that directly key in on risk groups enjoy enhanced outcomes compared with treatment as usual. For the maintenance of chronic musculoskeletal pain problems, there are several instruments that classify patients into specific groups or profiles, for example, on the basis of the avoidance and endurance model or the International Classification of Functioning, Disability and Health (ICF) assessment. Although some evidence shows that these classifications are related to treatment outcome, we found no study that directly tested a system for providing treatment matched to the subgrouping for maintenance.

CONCLUSIONS

We conclude that it is possible to reliably subgroup patients with musculoskeletal problems. Likewise, treatments that address the risk factors in the screening procedure may enhance outcomes compared with treatment as usual. More work is needed, however, to better understand the mechanism, so that assessment methods can be improved, and treatment specific to subgroups can be developed and evaluated.

"Selling" chronic pain: physiotherapists' lived experiences of communicating the diagnosis of chronic nonspecific lower back pain to their patients

Introduction: Chronic nonspecific lower back pain (CNSLBP) is a common musculoskeletal condition which can be a source of significant distress and disability for patients. Approaches to managing CNSLBP have been explored in healthcare literature, as has the importance of communication in physiotherapy practice. However, no previous studies have explored clinicians' experiences of communicating their understanding of this diagnosis to their patients.Methods: A qualitative research design, using hermeneutic phenomenological methodology, was employed. Five participants were purposively recruited for the research and data collected via semi-structured interviews. Interpretative phenomenological analysis (IPA) methods were used to analyze the data. Emergent, super-ordinate and master themes were developed to help convey the qualitative significant meanings of the lived-through experiences.Findings: Three master themes were identified, with each comprising two sub-themes. These were: 1) Patient-centeredness (1a. Understanding the patient; and 1b. emotional awareness and adaptability); 2) Getting patients "on board" (2a. the "selling" process; and 2b. paternalism and the clinician's perspective); and 3) Dealing with conflict and uncertainty (3a. fear of interpersonal conflict; and 3b. personal doubts and uncertainty).Conclusions: Personal conflicts were identified between clinicians' descriptions of their wishes to "sell" their own perspectives to patients while simultaneously wanting to demonstrate a patient-focused approach and avoid the interpersonal conflicts which arose from clashes with patients' beliefs. Building a good initial rapport, showing empathy and adapting approaches in response to perceptions of patients' reactions were perceived as strategies to help mitigate the risks of failed communication, but this was something for which participants felt unprepared by their prior training.

The Nordic Maintenance Care Program: Does psychological profile modify the treatment effect of a preventive manual therapy intervention? A secondary analysis of a pragmatic randomized controlled trial

BACKGROUND

Chiropractic maintenance care is effective as secondary/tertiary prevention of non-specific low back pain (LBP), but the potential effect moderation by psychological characteristics is unknown. The objective was to investigate whether patients in specific psychological sub-groups had different responses to MC with regard to the total number of days with bothersome pain and the number of treatments.

METHOD

Data from a two-arm randomized pragmatic multicenter trial with a 12-month follow up, designed to investigate the effectiveness of maintenance care, was used. Consecutive patients, 18-65 years of age, with recurrent and persistent LBP seeking chiropractic care with a good effect of the initial treatment were included. Eligible subjects were randomized to either maintenance care (prescheduled care) or to the control intervention, symptom-guided care. The primary outcome of the trial was the total number of days with bothersome LBP collected weekly for 12 months using an automated SMS system. Data used to classify patients according to psychological subgroups defined by the West Haven-Yale Multidimensional Pain Inventory (adaptive copers, interpersonally distressed and dysfunctional) were collected at the screening visit.

RESULTS

A total of 252 subjects were analyzed using a generalized estimating equations linear regression framework. Patients in the dysfunctional subgroup who received maintenance care reported fewer days with pain (-30.0; 95% CI: -36.6, -23.4) and equal number of treatments compared to the control intervention. In the adaptive coper subgroup, patients who received maintenance care reported more days with pain (10.7; 95% CI: 4.0, 17.5) and more treatments (3.9; 95% CI: 3.5, 4.2). Patients in the interpersonally distressed subgroup reported equal number of days with pain (-0.3; 95% CI: -8.7, 8.1) and more treatments (1.5; 95% CI: 0.9, 2.1) on maintenance care.

CONCLUSIONS

Psychological and behavioral characteristics modify the effect of MC and should be considered when recommending long-term preventive management of patients with recurrent and persistent LBP.

Subgroups in chronic low back pain patients - a step toward cluster-based, tailored treatment in inpatient standard care: On the need for precise targeting of treatment for chronic low back pain

Objective: The purpose of this study was to find applicable clusters for the development of different treatment pathways in an inpatient multimodal pain-therapy setting based on the multifaceted nature of CLBP. Methods: Based on data of questionnaires (Hospital Anxiety and Depression Scale (HADS), Marburg Questionnaire on Habitual Health Findings (MFHW), quality of life assessment using the Short-Form 12 (SF 12)), a retrospective two-step cluster analysis involving a sample of chronic low back pain (CLBP) patients (N=320) was calculated. Subsequently, the clusters were precisely described and compared on the basis of further data collected during the patients' standard care: pain characteristics, socio-demographic data and the general state of health, psychological variables, therapy intensity, and Diagnosis Related Groups (DRG) data. Results: We found a three-cluster solution: little psychological interference but marginal physical and mental quality of life (Cluster 1); poor well-being, low physical quality of life, and marginal mental quality of life (Cluster 2); and heavy mental strain and marginal physical quality of life (Cluster 3). Conclusions: Similar to previous studies, our results suggest that patients suffering from CLBP differ with regard to the magnitude of mental burden and the presence of physical impairment. These differences ascertain the need for precise targeting of treatment for CLBP. Inpatient pain centers therefore should offer different multimodal therapy pathways and integrate a meaningful triage, taking into account the multifaceted nature of CLBP based on sophisticated knowledge about forms, differences, and relationships among the biopsychosocial components of CLBP.

Psychosocial and behavioural characteristics in women with pregnancy-related lumbopelvic pain 12 years postpartum

Background

There is insufficient evidence regarding psychosocial factors and its long-term association with persistent pregnancy-related lumbopelvic pain. The overall aim of this study was to investigate women with persistent pregnancy-related lumbopelvic pain 12 years postpartum based on psychosocial and behavioural characteristics using the Swedish version of the Multidimensional Pain Inventory (MPI-S) classification system.

Material and methods

This is a cross-sectional study based on a previous cohort. Data collection took place through a questionnaire. A total of 295 women from the initial cohort (n = 639) responded to the questionnaire giving a response rate of 47.3%. To determine the relative risk (RR) of reporting pain 12 years postpartum, a robust modified Poisson regression was used. This is the first study using the MPI-S as a predictive variable on women with persistent pregnancy-related lumbopelvic pain.

Results

The MPI-S classification procedure was carried out on a total of n = 226 women, where 53 women were classified as interpersonally distressed (ID), 82 as dysfunctional (DYS), and 91 as adaptive copers (AC). Women in the ID and DYS subgroups had a relative risk (RR) of reporting persistent pregnancy-related lumbopelvic pain 12 years postpartum that was more than twice as high compared to the AC subgroup (95% confidence interval (CI) in parenthesis): RR 2.57 (CI 1.76 - 3.75), p<0.0001 and RR 2.23 (CI 1.53 - 3.25), p<0.0001 respectively. Women in the DYS subgroup had more than 5 times increased risk of reporting sick leave the past 12 months compared to the AC subgroup (RR 5.44; CI 1.70 - 17.38, p=0.004).

Conclusions

The present study demonstrates that it is possible to classify women with persistent pregnancy-related lumbopelvic pain 12 years postpartum into relevant clinical subgroups based on psychosocial and behavioural characteristics using the MPI-S questionnaire.

Symptom-based latent classes of persons with irritable bowel syndrome

A large amount of interindividual variability exists in symptom experiences of persons with irritable bowel syndrome (IBS). Thus, consideration of multiple symptoms to identify distinct symptom subgroups may be useful in directing personalized health strategies for symptom management. We aimed to identify latent classes (i.e., subgroups) of persons with IBS who share similar patterns of symptoms using symptom-related variables (six groups of daily diary symptoms, cognitive beliefs about IBS, and IBS quality of life [QOL]); and to examine how subgroups differed in patient characteristics. Data were derived from a baseline assessment of men and women enrolled in two cognitively-focused intervention trials (N = 332). Using latent class analysis, four latent classes were identified: Class 1 (low symptoms and good QOL, n = 153), Class 2 (low symptoms and moderate QOL, n = 106), Class 3 (high symptoms with diarrhea and poor QOL, n = 38), and Class 4 (high symptoms with low diarrhea and moderate QOL, n = 35). Diarrhea, being female, less formal education, unemployment, and previous history of major depressive disorder were associated with membership in Class 3. Using these distinct symptom profiles, the next step is to explore underlying mechanisms accounting for symptom burden with the goal of designing tailored interventions to reduce that burden.

Partners' Overestimation of Patients' Pain Severity: Relationships with Partners' Interpersonal Responses

Objectives

The present study examined whether concordance between patients' and their partners' reports of patient pain severity relates to partners' social support and behavioral responses in couples coping with chronic pain.

Methods

Fifty-two couples completed questionnaires about the patient's pain severity. Both dyad members also rated the partner's social support and negative, solicitous, and distracting responses toward the patient when in pain.

Results

Bivariate correlations showed moderate correspondence between patient and partner ratings of pain severity (r = 0.55) and negative (r = 0.46), solicitous (r = 0.47), and distracting responses (r = 0.53), but lower correspondence for social support (r = 0.28). Twenty-eight couples (54%) were concordant in their perceptions of patient pain; partners overestimated pain in 14 couples (27%), and partners underestimated pain in 10 couples (19%). Couple concordance in pain perceptions was not related to patients' reports; however, it significantly predicted partners' reports: Partners who overestimated pain reported giving more social support (β = 0.383, P = 0.016), fewer negative responses (β = -0.332, P = 0.029), and more solicitous responses (β = 0.438, P = 0.016) than partners who were in agreement or who underestimated pain.

Discussion

Partner overestimation of pain severity is associated with partner-reported but not with patient-reported support-related responses. This finding has important clinical implications for couple interventions in chronic pain.

Applications of dynamic functional connectivity to pain and its modulation

Since early work attempting to characterize the brain's role in pain, it has been clear that pain is not generated by a specific brain region, but rather by coordinated activity across a network of brain regions, the "neuromatrix." The advent of noninvasive whole-brain neuroimaging, including functional magnetic resonance imaging, has provided insight on coordinated activity in the pain neuromatrix and how correlations in activity between regions, referred to as "functional connectivity," contribute to pain and its modulation. Initial functional connectivity investigations assumed interregion connectivity remained stable over time, and measured variability across individuals. However, new dynamic functional connectivity (dFC) methods allow researchers to measure how connectivity changes over time within individuals, permitting insights on the dynamic reorganization of the pain neuromatrix in humans. We review how dFC methods have been applied to pain, and insights afforded on how brain connectivity varies across time, either spontaneously or as a function of psychological states, cognitive demands, or the external environment. Specifically, we review psychophysiological interaction, dynamic causal modeling, state-based dynamic community structure, and sliding-window analyses and their use in human functional neuroimaging of acute pain, chronic pain, and pain modulation. We also discuss promising uses of dFC analyses for the investigation of chronic pain conditions and predicting pain treatment efficacy and the relationship between state- and trait-based pain measures. Throughout this review, we provide information regarding the advantages and shortcomings of each approach, and highlight potential future applications of these methodologies for better understanding the brain processes associated with pain.

Acceptance and commitment therapy for chronic pain: protocol of a systematic review and individual participant data meta-analysis

BACKGROUND

Acceptance and commitment therapy (ACT) can be effective in treating chronic pain. Despite evidence supporting the effectiveness of ACT, uncertainties remain regarding which subgroups in the chronic pain population are likely to benefit most and least. This protocol describes the application for two meta-analytic approaches, one at the level of individual participant data and the other at the level of aggregated data, from randomized controlled trials of ACT for chronic pain (ACT-CP-MA).

METHODS

We will systematically conduct literature searches in CENTRAL, MEDLINE, EMBASE, PsycINFO, and trial registers. Two reviewers will independently select studies for inclusion and data extraction. ACT-CP-MA will include randomized controlled trials with ACT for chronic pain compared to control conditions for adults (≥ 18 years) with chronic pain (> 3 months). We will invite the authors of all eligible trials to share individual participant data. Outcomes will include standardized measures of pain interference, pain intensity, depression, anxiety, health-related quality of life, participants' rating of overall improvement, and ACT-related process variables. Using the Cochrane Collaboration's tool and GRADE, reviewers will independently check for risk of bias, quality of evidence, and strength of recommendations. In the individual participant data meta-analysis, we will use a one-step approach where participants are clustered with studies and data from all studies are modeled simultaneously. For analyses, we will use mixed-effects models. Additionally, we will employ a meta-analysis with aggregate data and compare the results of both meta-analyses.

DISCUSSION

This collaborative meta-analysis of individual participant data from randomized controlled trials of ACT for chronic pain versus control conditions will demonstrate how the known benefits of ACT for chronic pain vary across different subtypes of the chronic pain population. The results of the meta-analyses will be based on a comprehensive search of multiple databases and will help to inform future clinical trials and decision-making on the use of ACT in chronic pain and improve the quality, design, and reporting of future trials in this field.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019120901.

Hybrid Approach to Treatment Tailoring for Low Back Pain: A Proposed Model of Care

Various approaches have been used to guide the treatment of low back pain. These approaches have been considered in isolation and often tested against each other. An alternative view is that a model of care that involves a hybrid approach may benefit patients with low back pain. This commentary considers the potential benefits of a sequentially applied hybrid approach for treatment tailoring to optimize resource allocation to those most likely to require comprehensive care, and then decision making toward treatment paths with the greatest potential for success. In a first step, a prognosis-based approach, such as the Subgroups for Targeted Treatment Back Screening Tool (STarT Back), identifies individuals likely to require greater resource allocation. Although a clear path is indicated toward simple and psychologically informed care for the low- and high-risk groups, respectively, there is limited guidance for the large medium-risk group. For that group, the hybrid model provides a stepwise path of additional methods to guide treatment selection. This includes subgrouping based on pain mechanism to guide priority domains for the next phase, which includes tailoring of psychological and movement-based approaches. Motor control approaches to exercise would be indicated for individuals with medium risk and a nociceptive pain mechanism, with treatment guided by detailed assessment via one of several paradigms. Psychologically informed treatments are tailored to those with medium risk and a predominantly central pain mechanism, guided by detailed assessment of psychosocial features. A hybrid approach to a model of care could simplify treatment selection and take advantage of the benefits of each method in a time- and cost-efficient manner. J Orthop Sports Phys Ther 2019;49(6):453-463. Epub 13 Feb 2019. doi:10.2519/jospt.2019.8774.

Expectations influence treatment outcomes in patients with low back pain. A secondary analysis of data from a randomized clinical trial

Background

Low back pain (LBP) is a global public health challenge, which causes high healthcare costs and the highest burden on society in terms of years lived with disability. While patients’ expectations for improvement may have effects on LBP treatment outcomes, it remains unclear if psychological profiles modify this relationship. Therefore, the objectives of this study were to investigate if (a) patients’ expectations predicted short‐term outcome, and (b) psychological profile, pain intensity and self‐rated health modified the relationship between expectations and outcome.

Methods

Data were collected between April 2012 and January 2016 during the inclusion into a randomized controlled trial. Potentially eligible participants were identified through 40 chiropractic clinics located across Sweden. Patients’ expectations, psychological profile, pain intensity, activity limitation and self‐rated health were collected from patients with recurrent persistent LBP during their first chiropractic visit (n = 593). Subjective improvement was measured at the fourth visit.

Results

Patients with a high expectation of improvement had 58% higher risk to report an improvement at the fourth visit (RR = 1.58, 95% CI: 1.28, 1.95). Controlling for potential confounders only slightly decreased the strength of this association (RR = 1.49, 95% CI: 1.20, 1.86). Baseline pain intensity, psychological profile and self‐rated health did not modify the effect of expectation on outcome.

Conclusions

Baseline patients’ expectations play an important role when predicting LBP treatment outcomes. Clinicians should consider and address patients’ expectations at the first visit to best inform prognosis.

Significance

This study confirms the importance of patients’ expectations in a clinical setting. Patients’ expectations predict the short‐term outcome of chiropractic care for LBP. Pain intensity, psychological profile and self‐rated health did not modify this relationship.

Vulnerability and Resilience in Patients with Chronic Pain in Occupational Healthcare: A Pilot Study with a Patient-Centered Approach

OBJECTIVES

The aim of this pilot study was to describe vulnerability and resilience and possible subgroups in patients with chronic work related musculoskeletal pain in occupational healthcare. A second aim was to evaluate a patient-centered approach.

METHODS

This study was based on consecutive patients with chronic pain, seen by the same physician and sick-listed full or part time three months or longer. They were included during a period of three months. Patient reported outcome measures (PROM) were administered at baseline and at follow-up after 8 months. A patient-centered approach was applied where the patient's whole situation was taken into account.

RESULTS

A dominance of an insecure dismissing attachment pattern and a subnormal sense of coherence (SOC) was reported both at baseline and at follow-up. The patients (n=38) reported significant improvement of pain severity (p=0.01), pain interference (p=0.001), life control (p=0.01), affective distress (p=0.02), and dysfunction (p=0.001) on the multidimensional pain inventory (MPI) and fewer patients were sick-listed full time at follow-up (13 patients versus 21). By means of multivariate data analyses this change in MPI was confirmed and was also correlated with a significant increase in health related quality of life (HRQoL). Moreover subgroups with different outcome at follow-up were identified according to attachment pattern and subgroups on MPI.

CONCLUSION

A patient-centered approach may be of value for patients with chronic pain in occupational healthcare, improving pain and dysfunction. Patients with chronic pain are a heterogeneous group where outcome of treatment might be influenced by individual resilience and/or vulnerability.

Effect of Mobile Device-Supported Single-Patient Multi-crossover Trials on Treatment of Chronic Musculoskeletal Pain: A Randomized Clinical Trial

IMPORTANCE

Individually designed single-patient multi-crossover (n-of-1) trials can facilitate tailoring of treatments directed at various conditions, including chronic musculoskeletal pain (CMSP) but are potentially burdensome, which may limit uptake in research and practice.

OBJECTIVES

To determine whether patients randomized to participate in an n-of-1 trial supported by a mobile health (mHealth) app would experience less pain and improved global health, adherence, satisfaction, and shared decision making compared with patients assigned to usual care.

DESIGN, SETTING, AND PARTICIPANTS

This randomized clinical trial compared participation in an individualized, mHealth-supported n-of-1 trial vs usual care. The participating 215 patients had CMSP for at least 6 weeks, had a smartphone or tablet with a data plan, were enrolled in northern California from July 2014 through July 2016, and were followed for up to 1 year by 48 clinicians in academic, community, Veterans Affairs, and military settings.

INTERVENTIONS

Intervention patients met with their clinicians and used a desktop interface to select treatments and trial parameters for an n-of-1 trial comparing 2 pain-management regimens. The mHealth app provided reminders to take designated treatments on assigned days and to upload responses to daily questions on pain and treatment-associated adverse effects. Control patients received care as usual.

MAIN OUTCOMES AND MEASURES

The primary outcome was change in the PROMIS (Patient-Reported Outcomes Measurement Information System) pain-related interference 8-item short-form scale (full scale range, 41-78) from baseline to 6 months. Secondary outcomes included patient-reported pain intensity, overall health, analgesic adherence, trust in clinician, satisfaction with care, medication-related shared decision making, and, for the n-of-1 group only, participant engagement and experience.

RESULTS

Among 215 patients (108 randomized to the n-of-1 intervention and 107 to control), 102 (47%) were women, and the mean (SD) age was 55.5 (11.1) years. At the 6-month follow-up, pain interference was reduced in both groups, though there was no difference between the intervention and control groups (-1.36 points; 95% CI, -2.91 to 0.19 points; P = .09). There were no advantages in secondary outcomes for intervention patients vs control patients except for higher medication-related shared decision making at 6 months (between-group difference, 11.9 points; 95% CI, 2.6-21.2 points; P = .01). Among patients assigned to the n-of-1 group, 88% (n = 86) affirmed that the mHealth app could help people like them manage their pain.

CONCLUSIONS AND RELEVANCE

In this population of patients with CMSP, mHealth-supported n-of-1 trials were feasible and associated with a satisfactory user experience, but n-of-1 trial participation did not significantly improve pain interference at 6 months vs usual care.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02116621.

A theoretically guided approach to identifying predictors of treatment outcome in Contextual Cognitive Behavioural Therapy for chronic pain

BACKGROUND

Psychological treatments are known to be effective for chronic pain, but little is understood about which patients are most likely to benefit from which ones.

METHODS

The study reported here included 609 people who attended a residential, interdisciplinary, pain management programme based on Acceptance and Commitment Therapy between January 2012 and August 2014. A flexible and theoretically guided approach to model building based on fractional polynomials was used to identify potential predictors of outcome in domains of emotional, physical and social functioning and pain intensity. Variables considered for inclusion were baseline demographic variables along with measures reflecting processes of psychological flexibility, including acceptance, cognitive defusion and committed action.

RESULTS

Employment status, level of distress, decentring (a process like cognitive defusion) and acceptance significantly contributed to the model above and beyond the effects of other baseline variables. The unique effects of these were small but may be clinically relevant.

CONCLUSIONS

Future research should continue to investigate moderators of treatment outcome and to explicitly link these to treatment mechanisms. Taking a flexible, theoretically driven approach to modelling continuous outcomes may be valuable in furthering our understanding of which patients might respond best to which treatments.

SIGNIFICANCE

Further research is needed to better understand who benefits most from psychological treatments for chronic pain. This study suggests that a flexible, multivariate and theoretical approach to identifying predictors of outcome may be valuable in furthering research in this area.

Behavioral Therapy Approaches for the Management of Low Back Pain: An Up-To-Date Systematic Review

Low back pain is one of the most common causes for seeking medical treatment and it is estimated that one in two people will experience low back pain at some point during their lifetimes. Management of low back pain includes pharmacological and non-pharmacological approaches. Non-pharmaceutical treatments include interventions such as acupuncture, spinal manipulation, and psychotherapy. The latter is especially important as patients who suffer from low back pain often have impaired quality of life and also suffer from depression. Depressive symptoms can appear because back pain limits patients’ ability to work and engage in their usual social activities. The aim of this systematic review was to overview the behavioral approaches that can be used in the management of patients with low back pain. Approaches such as electromyography (EMG) biofeedback, cognitive behavioral therapy, and mindfulness-based stress reduction are discussed as non-pharmacological options in the management of low back pain.

A Couple-Based Psychological Treatment for Chronic Pain and Relationship Distress

Chronic pain impacts individuals with pain as well as their loved ones. Yet, there has been little attention to the social context in individual psychological treatment approaches to chronic pain management. With this need in mind, we developed a couple-based treatment, "Mindful Living and Relating," aimed at alleviating pain and suffering by promoting couples' psychological and relational flexibility skills. Currently, there is no integrative treatment that fully harnesses the power of the couple, treating both the individual with chronic pain and the spouse as two individuals who are each in need of developing greater psychological and relational flexibility to improve their own and their partners' health. Mindfulness, acceptance, and values-based action exercises were used to promote psychological flexibility. The intervention also targets relational flexibility, which we define as the ability to interact with one's partner, fully attending to the present moment, and responding empathically in a way that serves one's own and one's partner's values. To this end, the intervention also included exercises aimed at applying psychological flexibility skills to social interactions as well as emotional disclosure and empathic responding exercises to enhance relational flexibility. The case presented demonstrates that healthy coping with pain and stress may be most successful and sustainable when one is involved in a supportive relationship with someone who also practices psychological flexibility skills and when both partners use relational flexibility skills during their interactions.

Body Awareness as an Important Target in Multidisciplinary Chronic Pain Treatment: Mediation and Subgroup Analyses

BACKGROUND

The results of a recently performed randomized clinical trial showed that the effect of a multidisciplinary treatment of chronic pain patients on body awareness (BA), catastrophizing, and depression was improved by adding psychomotor therapy (PMT), an intervention targeting BA. No significant effects were found on quality of life and disability. The present follow-up study aimed to explore the relationship between improvements in BA and multidisciplinary chronic pain rehabilitation treatment outcome across treatment conditions and the possible mediating effect of BA between treatment conditions. Furthermore, the hypothesis that patients with low BA benefit more from PMT was investigated.

METHODS

In total, 94 patients with chronic pain participated in a randomized clinical trial comparing multidisciplinary treatment as usual (TAU) with TAU plus PMT. Outcome variables were health-related quality of life, disability, and depression. Self-efficacy and catastrophizing were the process variables of treatment and the potential mediating factors in the relationship between BA and the outcome variables. The data were analyzed by linear mixed-model analysis.

RESULTS

Improvements in BA were related to improvements in all outcome variables across treatment conditions. The relationships were partly mediated by self-efficacy, catastrophizing, or both. In the regression model with depression as the outcome variable, the regression coefficient of treatment (ie, PMT vs. TAU) decreased by 34% and became nonsignificant when BA was added as a potential mediator. Patients with low BA seemed to benefit more from PMT than patients with high BA, especially on depression, BA, and catastrophizing.

CONCLUSIONS

BA might be an important target of treatment to improve the multidisciplinary treatment outcome in chronic pain patients. Furthermore, PMT is an intervention that seems to provide its benefits through improving BA and may be especially beneficial for patients with low BA.

Predictors of Treatment Outcome in Contextual Cognitive and Behavioral Therapies for Chronic Pain: A Systematic Review

There is increasing evidence that contextual forms of cognitive-behavioral therapy (CBT) are effective in the management of chronic pain, yet little is understood about the factors that moderate or predict outcomes in these treatments. This systematic review aimed to identify pretreatment participant characteristics associated with positive treatment responses in contextual CBT for chronic pain. Medline, EMBASE, PsychINFO, and CENTRAL were searched to identify eligible studies. Studies were included if the participants were adults with chronic pain, designs were longitudinal, treatments focused on psychological flexibility or mindfulness, and reported results allowed for examination of moderators or predictors of standard treatment outcomes. Of 991 records initially identified, 20 were eligible for inclusion in the review. Some evidence suggested that baseline emotional functioning predicts treatment response, but the direction of this association varied between studies. Substantive findings were inconsistent and inconclusive, however, methodological limitations were consistent. These included treatment heterogeneity, and a lack of theoretical, a priori guidance in examining potential predictors. Future research should adopt a theoretically based approach to examining moderators in relation to specific treatment methods and therapeutic processes. Considering moderation without first considering mediation is probably a limited strategy.

PERSPECTIVE

In this systematic review we examined evidence for potential predictors or moderators of outcomes in contextual CBT for chronic pain. Substantive findings were inconclusive but important methodological limitations and a lack of theoretical guidance were found. Future research should explicitly plan relevant methods and follow clear theoretical models.

Mediators and treatment matching in behavior therapy, cognitive therapy and cognitive behavior therapy for chronic insomnia

OBJECTIVE

To examine the mediators and the potential of treatment matching to improve outcome for cognitive behavior therapy (CBT) for insomnia.

METHOD

Participants were 188 adults (117 women; Mage = 47.4 years, SD = 12.6) meeting the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; text rev.; DSM-IV-TR; American Psychiatric Association [APA], 2000) diagnostic criteria for chronic insomnia (Mduration: 14.5 years, SD: 12.8). Participants were randomized to behavior therapy (BT; n = 63), cognitive therapy (CT; n = 65), or CBT (n = 60). The outcome measure was the Insomnia Severity Index (ISI). Hypothesized BT mediators were sleep-incompatible behaviors, bedtime variability (BTv), risetime variability (RTv) and time in bed (TIB). Hypothesized CT mediators were worry, unhelpful beliefs, and monitoring for sleep-related threat.

RESULTS

The behavioral processes mediated outcome for BT but not CT. The cognitive processes mediated outcome in both BT and CT. The subgroup scoring high on both behavioral and cognitive processes had a marginally significant better outcome if they received CBT relative to BT or CT. The subgroup scoring relatively high on behavioral but low on cognitive processes and received BT or CBT did not differ from those who received CT. The subgroup scoring relatively high on cognitive but low on behavioral processes and received CT or CBT did not differ from those who received BT.

CONCLUSION

The behavioral mediators were specific to BT relative to CT. The cognitive mediators were significant for both BT and CT outcomes. Patients exhibiting high levels of both behavioral and cognitive processes achieve better outcome if they receive CBT relative to BT or CT alone. (PsycINFO Database Record

Symptoms-Based Phenotypes Among Women With Dysmenorrhea: A Latent Class Analysis

Dysmenorrhea is highly prevalent and may increase women's risk for developing other chronic pain conditions. Although it is highly variable, symptom-based dysmenorrhea phenotypes have not been identified. The aims of the study were to identify symptom-based dysmenorrhea phenotypes and examine their relationships with demographic and clinical characteristics. In a cross-sectional study, 762 women with dysmenorrhea rated severity of 14 dysmenorrhea-related symptoms. Using latent class analysis, we identified three distinctive phenotypes. Women in the "mild localized pain" phenotype ( n = 202, 26.51%) had mild abdominal cramps and dull abdominal pain/discomfort. Women in the "severe localized pain" phenotype ( n = 412, 54.07%) had severe abdominal cramps. Women in the "multiple severe symptoms" phenotype ( n = 148, 19.42%) had severe pain at multiple locations and multiple gastrointestinal symptoms. Race, ethnicity, age, and comorbid chronic pain conditions were significantly associated with phenotypes. Identification of these symptom-based phenotypes provides a foundation for research examining genotype-phenotype associations, etiologic mechanisms, and/or variability in treatment responses.

Prognostic factors for chronic headache: A systematic review

OBJECTIVE

To identify predictors of prognosis and trial outcomes in prospective studies of people with chronic headache.

METHODS

This was a systematic review of published literature in peer-reviewed journals. We included (1) randomized controlled trials (RCTs) of interventions for chronic headache that reported subgroup analyses and (2) prospective cohort studies, published in English, since 1980. Participants included adults with chronic headache (including chronic headache, chronic migraine, and chronic tension-type headache with or without medication overuse headache). We searched key databases using free text and MeSH terms. Two reviewers independently extracted data and assessed the methodologic quality of studies and overall quality of evidence identified using appropriate published checklists.

RESULTS

We identified 16,556 titles, removed 663 duplicates, and reviewed 199 articles, of which 27 were included in the review-17 prospective cohorts and 10 RCTs with subgroup analyses reported. There was moderate-quality evidence indicating that depression, anxiety, poor sleep and stress, medication overuse, and poor self-efficacy for managing headaches are potential prognostic factors for poor prognosis and unfavorable outcomes from preventive treatment in chronic headache. There was inconclusive evidence about treatment expectations, age, age at onset, body mass index, employment, and several headache features.

CONCLUSIONS

This review identified several potential predictors of poor prognosis and worse outcome postinterventions in people with chronic headache. The majority of these are modifiable. The findings also highlight the need for more longitudinal high-quality research of prognostic factors in chronic headache.

Determinants of pain and functioning in knee osteoarthritis: a one-year prospective study

Objective:

To identify predictors of pain and disability in knee osteoarthritis.

Design:

A one-year prospective analysis of determinants of pain and functioning in knee osteoarthritis.

Study setting:

Primary care providers in a medium-sized city.

Patients:

A total of 111 patients aged from 35 to 75 with clinical symptoms and radiographic grading (Kellgren-Lawrence 2–4) of knee osteoarthritis who participated in a randomized controlled trial.

Main measures:

The outcome measures were self-reported pain and function, which were recorded at 0, 3 and 12 months. Disease-specific pain and functioning were assessed using the pain and function subscales of the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index. Generic physical and mental functioning were assessed using the RAND-36 subscales for function, and physical and mental component summary scores. Possible baseline predictors for these outcomes were 1) demographic, socioeconomic and disease-related variables, and 2) psychological measures of resources, distress, fear of movement and catastrophizing.

Results:

Multivariate linear mixed model analyses revealed that normal mood at baseline measured with the Beck Anxiety Inventory predicted significantly better results in all measures of pain (WOMAC P=0.02) and function (WOMAC P=0.002, RAND-36 P=0.002) during the one-year follow-up. Psychological resource factors (pain self-efficacy P=0.012, satisfaction with life P=0.002) predicted better function (RAND-36). Pain catastrophizing predicted higher WOMAC pain levels (P=0.013), whereas fear of movement (kinesiophobia) predicted poorer functioning (WOMAC P=0.046, RAND-36 P=0.024).

Conclusions:

Multiple psychological factors in people with knee osteoarthritis pain are associated with the development of disability and longer term worse pain.

How can group-based multidisciplinary rehabilitation for patients with fibromyalgia influence patients' self-efficacy and ability to cope with their illness: a grounded theory approach

AIMS AND OBJECTIVES

To describe how group-based multidisciplinary rehabilitation for patients with fibromyalgia can influence patients' self-efficacy and ability to cope with their illness.

BACKGROUND

Multidisciplinary rehabilitation is recommended in the management of fibromyalgia. Self-efficacy is said to influence and predict adaptive coping behaviours and functioning. However, knowledge is lacking on how rehabilitation programmes may influence self-efficacy and ability to cope, from the patients' perspective.

DESIGN

Grounded theory study of semi-structured focus group interviews.

METHODS

Participants (n = 17) were included in four focus groups that had completed a two-week multidisciplinary rehabilitation programme together. Interviews were conducted four weeks after each group had completed the programme. The analysis was conducted constant comparatively applying open, axial and selective coding.

RESULTS

Categories (in italics) were derived from data in which the explanatory core category was identified: Learning to accept and live with pain as a life condition, and linked to three categories mutually influencing each other: Increased self-acceptance of living with the illness, experiencing acceptance from others and developing new coping strategies. Thus, patients benefitted from multidisciplinary rehabilitation with stronger self-efficacy and expectations to their future coping. However, limitations in the programme were identified, as the programme was short and intensive with no subsequent follow-up, and social welfare was not sufficiently addressed. Participants also found it difficult to maintain knowledge and were lacking individual sessions with the psychologist and had waited long to receive rehabilitation.

CONCLUSION

Multidisciplinary rehabilitation may advantageously be offered to patients with fibromyalgia. However, earlier action with longer programmes, in which patients' social situation is addressed, comprising individual sessions with the psychologist, with multiple repetitions of the content and follow-up sessions, may further enhance the patients' self-efficacy and coping with their illness.