Mechanisms, mechanisms, mechanisms: it really does all boil down to mechanisms

Non-pharmacological and non-surgical treatments for low back pain in adults: an overview of Cochrane reviews

BACKGROUND

Low back pain (LBP) is a significant public health issue due to its high prevalence and associated disability burden. Clinical practice guidelines recommend non-pharmacological/non-surgical interventions for managing pain and function in people with LBP.

OBJECTIVES

To provide accessible, high-quality evidence on the effects of non-pharmacological and non-surgical interventions for people with LBP and to highlight areas of remaining uncertainty and gaps in the evidence regarding the effects of these interventions for people with LBP.

METHODS

We searched the Cochrane Database of Systematic Reviews from inception to 15 April 2023, to identify Cochrane reviews of randomised controlled trials testing the effect of non-pharmacological/non-surgical interventions, unrestricted by language. Major outcomes were pain intensity, function and safety. Two authors independently assessed eligibility, extracted data and assessed the quality of the reviews using AMSTAR 2 (A MeaSurement Tool to Assess Systematic Reviews) and the certainty of the evidence using GRADE. The primary comparison was placebo/sham.

MAIN RESULTS

We included 31 Cochrane reviews of 644 trials that randomised 97,183 adults with LBP. We have high confidence in the findings of 19 reviews, moderate confidence in the findings of two reviews, and low confidence in the findings of 10 reviews. We present results for non-pharmacological/non-surgical interventions compared to placebo/sham or no treatment/usual care at short-term (≤ three months) follow-up. Placebo/sham comparisons Acute/subacute LBP Compared to placebo, there is probably no difference in function (at one-week follow-up) for spinal manipulation (standardised mean difference (SMD) -0.08, 95% confidence interval (CI) -0.37 to 0.21; 2 trials, 205 participants; moderate-certainty evidence). Data for safety were reported only for heated back wrap. Compared to placebo, heated back wrap may result in skin pinkness (6/128 participants versus 1/130; 2 trials; low-certainty evidence). Chronic LBP Compared to sham acupuncture, acupuncture probably provides a small improvement in function (SMD -0.38, 95% CI -0.69 to -0.07; 3 trials, 957 participants; moderate-certainty evidence). Compared to sham traction, there is probably no difference in pain intensity for traction (0 to 100 scale, mean difference (MD) -4, 95% CI -17.7 to 9.7; 1 trial, 60 participants; moderate-certainty evidence). Data for safety were reported only for acupuncture. There may be no difference between acupuncture and sham acupuncture for safety outcomes (risk ratio (RR) 0.68, 95% CI 0.42 to 1.10; I2 = 0%; 4 trials, 465 participants; low-certainty evidence). No treatment/usual care comparisons Acute/subacute LBP Compared to advice to rest, advice to stay active probably provides a small reduction in pain intensity (SMD -0.22, 95% CI -0.02 to -0.41; 2 trials, 401 participants; moderate-certainty evidence). Compared to advice to rest, advice to stay active probably provides a small improvement in function (SMD -0.29, 95% CI -0.09 to -0.49; 2 trials, 400 participants; moderate-certainty evidence). Data for safety were reported only for massage. There may be no difference between massage and usual care for safety (risk difference 0, 95% CI -0.07 to 0.07; 1 trial, 51 participants; low-certainty evidence). Chronic LBP Compared to no treatment, acupuncture probably provides a medium reduction in pain intensity (0 to 100 scale, mean difference (MD) -10.1, 95% CI -16.8 to -3.4; 3 trials, 144 participants; moderate-certainty evidence), and a small improvement in function (SMD -0.39, 95% CI -0.72 to -0.06; 3 trials, 144 participants; moderate-certainty evidence). Compared to usual care, acupuncture probably provides a small improvement in function (MD 9.4, 95% CI 6.15 to 12.65; 1 trial, 734 participants; moderate-certainty evidence). Compared to no treatment/usual care, exercise therapies probably provide a small to medium reduction in pain intensity (0 to 100 scale, MD -15.2, 95% CI -18.3 to -12.2; 35 trials, 2746 participants; moderate-certainty evidence), and probably provide a small improvement in function (0 to 100 scale, MD -6.8, 95% CI -8.3 to -5.3; 38 trials, 2942 participants; moderate-certainty evidence). Compared to usual care, multidisciplinary therapies probably provide a medium reduction in pain intensity (SMD -0.55, 95% CI -0.83 to -0.28; 9 trials, 879 participants; moderate-certainty evidence), and probably provide a small improvement in function (SMD -0.41, 95% CI -0.62 to -0.19; 9 trials, 939 participants; moderate-certainty evidence). Compared to no treatment, psychological therapies using operant approaches probably provide a small reduction in pain intensity (SMD -0.43, 95% CI -0.75 to -0.11; 3 trials, 153 participants; moderate-certainty evidence). Compared to usual care, psychological therapies (including progressive muscle relaxation and behavioural approaches) probably provide a small reduction in pain intensity (0 to 100 scale, MD -5.18, 95% CI -9.79 to -0.57; 2 trials, 330 participants; moderate-certainty evidence), but there is probably no difference in function (SMD -0.2, 95% CI -0.41 to 0.02; 2 trials, 330 participants; moderate-certainty evidence). It is uncertain whether there is a difference between non-pharmacological/non-surgical interventions and no treatment/usual care for safety (very low-certainty evidence).

AUTHORS' CONCLUSIONS

Spinal manipulation probably makes no difference to function compared to placebo for people with acute/subacute LBP. Acupuncture probably improves function slightly for people with chronic LBP, compared to sham acupuncture. There is probably no difference between traction and sham traction for pain intensity in people with chronic LBP. Compared to advice to rest, advice to stay active probably reduces pain intensity slightly and improves function slightly for people with acute LBP. Acupuncture probably reduces pain intensity, and improves function slightly for people with chronic LBP, compared to no treatment. Acupuncture probably improves function slightly for people with chronic LBP, compared to usual care. Exercise therapies probably reduce pain intensity, and improve function slightly for people with chronic LBP, compared to no treatment/usual care. Multidisciplinary therapies probably reduce pain intensity, and improve function slightly for people with chronic LBP, compared to usual care. Compared to usual care, psychological therapies probably reduce pain intensity slightly, but probably make no difference to function for people with chronic LBP.

Categorizing Treatment Mechanisms for Complementary and Integrative Musculoskeletal Interventions

Treatment mechanisms (TM) reflect the steps or processes through which a treatment unfolds. However, TM research faces challenges due to inconsistent terminology and varying measurement approaches for each mechanism, which creates confusion and controversy among clinicians and scientists. In this paper, we: 1) define key terms associated with TM, 2) provide recommended categories of study that reflect intervention domains, and 3) present examples of measures of TM within the defined categories. Our recommended definitions differentiate associated TM (a finding that occurs following administration of a treatment that may or may not influence outcomes) from causal TM (which directly affects the clinical outcome). When measuring causal TM, we recommend that researchers consider three potential categories of interventional domains: a) anatomical, b) psychological/cognitive and c) behavioral. Lastly, we argue that within each interventional domain, TM can be measured across a spectrum that includes physiological (e.g., brain activity, nerve activity, biomarkers, etc.) and functional (e.g., range of motion, stiffness, cognition measures, etc.) mechanisms. Measuring both physiological and functional mechanisms improves the likelihood of understanding the complexity of clinical recovery. Harmonizing TM terminology, categories, and measurements across a spectrum, while providing examples of each, may reduce confusion and assist researchers and funding sources in targeting specific mechanistic-related questions.

Identifying priority gaps in contextual factors research and force-based manipulation. An international and interdisciplinary Delphi study

OBJECTIVE

To establish priority gaps related to contextual factors (CFs) research and force-based manipulation (FBM).

METHODS

A three-round Delphi following recommended guidelines for conducting and reporting Delphi studies (CREDES) involving international and interdisciplinary panelists with expertise in CFs and FBM. Round 1 was structured around two prompting questions created by the workgroup. Ranking of each priority gap was done by calculating composite scores for each theme generated. Consensus threshold was set with an agreement ≥75% among panelists. Median and interquartile range were calculated for each priority gap to provide the central tendency of responses. Wilcoxon rank-sum test was used to evaluate the consistency and stability of responses between rounds 2 and 3.

RESULTS

Forty-six panelists participated in all three rounds of the Delphi. Consensus was reached for 16 of 19 generated themes for priority gaps in CFs research and FBM. The ranking of each identified gap was computed and presented. Wilcoxon rank-sum test was non-significant (P > .05), demonstrating consistency and stability of results between rounds.

CONCLUSION

The result of this Delphi provides international and interdisciplinary consensus-based priority gaps in CFs research and FBM. The gaps identified can be used to generate future research inquiries involving CFs research and FBM.

Self-regulation training for people with knee osteoarthritis: a protocol for a feasibility randomised control trial (MiNT trial)

Introduction

Knee osteoarthritis (OA) is a chronic secondary musculoskeletal pain condition resulting in disability, reduced quality of life, and high societal costs. Pain associated with knee OA is linked to increased sensitivity in sensory, cognitive, and emotional areas of the brain. Self-regulation training targeting brain functioning related to pain experience could reduce pain and its associated disability. Self-regulatory treatments such as mindfulness meditation (MM) and electroencephalography neurofeedback (EEG-NF) training improve clinical outcomes in people with knee OA. A feasibility clinical trial can address factors that could inform the design of the full trial investigating the effectiveness of self-regulation training programmes in people with knee OA. This clinical trial will evaluate the feasibility, safety, acceptability, experience and perceptions of the self-regulatory training programmes.

Methods

The proposed feasibility trial is based on a double-blind (outcome assessor and investigators), three-arm (MM usual care, EEG-NF + usual care and usual care control group) randomised controlled parallel clinical trial. Participants with knee OA will be recruited from the community and healthcare practices. A research assistant (RA) will administer both interventions (20-min sessions, four sessions each week, and 12 sessions over three successive weeks). Feasibility measures (participant recruitment rate, adherence to interventions, retention rate), safety, and acceptability of interventions will be recorded. An RA blinded to the group allocation will record secondary outcomes at baseline, immediately post-intervention (4th week), and 3 months post-intervention. The quantitative outcome measures will be descriptively summarised. The qualitative interviews will evaluate the participants' experiences and perceptions regarding various aspects of the trial, which includes identifying the barriers and facilitators in participating in the trial, evaluating their opinions on the research procedures, such as their preferences for the study site, and determining the level of acceptability of the interventions as potential clinical treatments for managing knee OA. Māori participant perceptions of how assessment and training practices could be acceptable to a Māori worldview will be explored. The interviews will be audio-recorded and analysed thematically.

Discussion

This trial will provide evidence on the feasibility, safety, and acceptability of the MM and EEG-NF training in people with knee OA, thus informing the design of a full randomised clinical control trial.

A non-inferiority randomized controlled trial comparing behavioral sleep interventions in women veterans: An examination of pain outcomes

OBJECTIVE

Insomnia is known to exacerbate pain symptoms. The purpose of the present study was to compare the secondary effects of cognitive behavioral therapy for insomnia (CBTI) against a novel treatment for insomnia called acceptance and behavioral changes for insomnia (ABC-I) among individuals with comorbid pain. Differences in the potential mechanisms through which these treatments impact pain were also examined.

METHODS

Data consisted of a secondary analysis from a randomized comparative effectiveness trial of CBT-I and ABC-I among women veterans with insomnia and comorbid pain. Pain outcomes, beliefs about sleep, and psychological flexibility were assessed at baseline, post-treatment, and at three-months follow-up.

RESULTS

At baseline, 93 women veterans reported comorbid insomnia and pain (mean age = 46.7; 33.3% Black, 24.7% Hispanic/Latina). Both CBT-I (n = 48) and ABC-I (n = 45) were associated with decreased pain intensity (p < .001, Cohen's d = 0.41-0.67) and pain interference (p < .001, Cohen's d = 0.71-0.77) at post-treatment and three-months follow-up, with results indicating that ABC-I was non-inferior to CBT-I for pain improvement. Both conditions were associated with greater psychological flexibility post-treatment, and CBT-I resulted in larger reductions in dysfunctional beliefs about sleep (p = .01, Cohen's d = 0.59).

CONCLUSION

CBT-I and ABC-I both had positive secondary effects on pain with ABC-I being non-inferior to CBT-I with respect to its impact on pain. The mechanisms of change associated with these treatments may differ with CBT-I leading to greater reductions in dysfunctional beliefs. Hybrid treatments which incorporate an acceptance and commitment approach to both insomnia and pain warrant further examination.

The Timing and Magnitude of Improvements in Depression, Anxiety, Disability, and Pain Intensity During an Internet-delivered Program for Chronic Pain

Numerous studies have found that pain management programs are an effective treatment option for people with chronic pain. However, little is known about when people experience improvements during these programs and why they are effective. Using a secondary analysis, the current study examined the timing and magnitude of symptom change during an 8-week internet-delivered psychological pain management program for people with chronic pain. The change in 4 outcomes was examined: depression (n = 881), anxiety (n = 561), disability (n = 484), and pain intensity (n = 484). The largest improvements in depression, anxiety, and disability were reported during the first half of treatment (ie, 4 weeks), whereas the largest reductions in pain intensity were reported during the second half of treatment. Half the participants had experienced a clinically meaningful improvement in depression or anxiety, and a third of participants had reported such an improvement in disability by midtreatment (ie, 5 weeks after baseline). In a subgroup analysis (n = 397), this pattern of change in depression and anxiety symptoms did not differ based on the level of therapist guidance. This study highlights the importance of the first few weeks of psychological pain management programs and encourages future work to examine how the mechanisms underpinning rapid change may be harnessed to optimize care for people with chronic pain. PERSPECTIVE: This study found that depression, anxiety, and disability improved rapidly during the first half of an 8-week internet-delivered pain management program, and most of the prepost change had occurred by midtreatment. This work highlights the therapeutic potential of the first few treatment sessions and prompts future research into a rapid responding.

Using Daily Ratings to Examine Treatment Dose and Response in Cognitive Behavioral Therapy for Chronic Pain: A Secondary Analysis of the Co-Operative Pain Education and Self-Management Clinical Trial

BACKGROUND

Cognitive behavioral therapy for chronic pain (CBT-CP) has a strong evidence base, but little is known about when treatment benefits are achieved. The present study is a secondary analysis of individuals with chronic back pain recruited for a noninferiority trial comparing interactive voice response (IVR) CBT-CP with in-person CBT-CP.

METHODS

On the basis of data from daily IVR surveys, a clinically meaningful change was defined as a 30% reduction in pain intensity (n = 108) or a 45% increase in daily steps (n = 104) compared with the baseline week. We identified individuals who achieved a meaningful change at any point during treatment, and then we compared those who maintained a meaningful change in their final treatment week (i.e., responders) with those who did not or who achieved a meaningful change but lapsed (i.e., nonresponders).

RESULTS

During treatment, 46% of participants achieved a clinically meaningful decrease in pain intensity, and 66% achieved a clinically significant increase in number of steps per day. A total of 54% of patients were classified as responders in terms of decreases in pain intensity, and 70% were responders in terms of increases in step count. Survival analyses found that 50% of responders first achieved a clinically meaningful change by week 4 for pain intensity and week 2 for daily steps. Dropout and demographic variables were unrelated to responder status, and there was low agreement between the two measures of treatment response.

CONCLUSIONS

Collectively, results suggest that most responders improve within 4 weeks. Evaluating treatment response is highly specific to the outcome measure, with little correlation across outcomes.

Mediating Role of Treatment Perceptions in the Relationship Between Individual Characteristics and Engagement With a Digital Psychological Intervention for Pediatric Chronic Pain: Secondary Data Analysis

BACKGROUND

Engagement predicts benefits from self-managed treatments. However, engagement is an important concern in digital interventions, with over 50% of patients being nonadherent to interventions in chronic conditions such as chronic pain. Little is known about the individual characteristics that contribute to engagement with a digital self-management treatment.

OBJECTIVE

This study tested the mediating role of treatment perceptions (difficulty and helpfulness) in the association between individual baseline characteristics (treatment expectancies and readiness to change) and treatment engagement (online and offline) with a digital psychological intervention for adolescents with chronic pain.

METHODS

A secondary data analysis of a single-arm trial of Web-based Management of Adolescent Pain, a self-guided internet intervention developed for the management of chronic pain in adolescents, was conducted. Survey data were collected at baseline (T1), midtreatment (ie, 4 weeks after the treatment started; T2), and post treatment (T3). Online engagement was assessed using back-end information on the number of days adolescents accessed the treatment website, while the offline engagement was assessed with the reported frequency of use of skills (ie, pain management strategies) learned at the end of the treatment. Four parallel multiple mediator linear regression models, using ordinary least square regression incorporating the variables were tested.

RESULTS

In total, 85 adolescents with chronic pain (12-17 years old, 77% female) participated. Several mediation models were significant in predicting online engagement. A significant indirect effect was found for the path expectancies-helpfulness-online engagement (effect 0.125; SE 0.098; 95% CI 0.013-0.389) and for the path precontemplation-helpfulness-online engagement (effect -1.027; SE 0.650; 95% CI -2.518 to -0.054). Fourteen percent of the variance of online engagement was explained by the model including expectancies as a predictor (F₃=3.521; P<.05), whereas 15% was explained by the model where readiness to change was the predictor (F₃=3.934; P<.05). Offline engagement was partially explained in the model including readiness to change as the predictor but with marginal significance (F₃=2.719; R²=0.111; P=.05).

CONCLUSIONS

Treatment perception, specifically, perceived helpfulness, was a mediator of the pathway between both treatment expectancies and readiness to change and online engagement with a digital psychological intervention for chronic pain. Assessing these variables at baseline and midtreatment may help to determine the risk of nonadherence. Further work is needed to confirm these mediation pathways in larger samples.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04043962; https://clinicaltrials.gov/ct2/show/NCT04043962.

Mindfulness-Based Stress Reduction, Cognitive Behavioral Therapy, and Acupuncture in Chronic Low Back Pain: Protocol for Two Linked Randomized Controlled Trials

BACKGROUND

Nonpharmacologic mind-body therapies have demonstrated efficacy in low back pain. However, the mechanisms underlying these therapies remain to be fully elucidated.

OBJECTIVE

In response to these knowledge gaps, the Stanford Center for Low Back Pain-a collaborative, National Institutes of Health P01-funded, multidisciplinary research center-was established to investigate the common and distinct biobehavioral mechanisms of three mind-body therapies for chronic low back pain: cognitive behavioral therapy (CBT) that is used to treat pain, mindfulness-based stress reduction (MBSR), and electroacupuncture. Here, we describe the design and implementation of the center structure and the associated randomized controlled trials for characterizing the mechanisms of chronic low back pain treatments.

METHODS

The multidisciplinary center is running two randomized controlled trials that share common resources for recruitment, enrollment, study execution, and data acquisition. We expect to recruit over 300 chronic low back pain participants across two projects and across different treatment arms within each project. The first project will examine pain-CBT compared with MBSR and a wait-list control group. The second project will examine real versus sham electroacupuncture. We will use behavioral, psychophysical, physical measure, and neuroimaging techniques to characterize the central pain modulatory and emotion regulatory systems in chronic low back pain at baseline and longitudinally. We will characterize how these interventions impact these systems, characterize the longitudinal treatment effects, and identify predictors of treatment efficacy.

RESULTS

Participant recruitment began on March 17, 2015, and will end in March 2023. Recruitment was halted in March 2020 due to COVID-19 and resumed in December 2021.

CONCLUSIONS

This center uses a comprehensive approach to study chronic low back pain. Findings are expected to significantly advance our understanding in (1) the baseline and longitudinal mechanisms of chronic low back pain, (2) the common and distinctive mechanisms of three mind-body therapies, and (3) predictors of treatment response, thereby informing future delivery of nonpharmacologic chronic low back pain treatments.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02503475; https://clinicaltrials.gov/ct2/show/NCT02503475.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/37823.

Pain management in people with severe mental illness: an agenda for progress

Supplemental Digital Content is Available in the Text.

What Are the Mechanisms of Action of Cognitive-Behavioral, Mind-Body, and Exercise-based Interventions for Pain and Disability in People With Chronic Primary Musculoskeletal Pain?: A Systematic Review of Mediation Studies From Randomized Controlled Trials

OBJECTIVES

This systematic review examined studies that used mediation analysis to investigate the mechanisms of action of cognitive-behavioral, mind-body, and exercise-based interventions for pain and disability in people with chronic primary musculoskeletal pain.

MATERIALS AND METHODS

We searched 5 electronic databases for articles that conducted mediation analyses of randomized controlled trials to either test or estimate indirect effects.

RESULTS

We found 17 studies (n=4423), including 90 mediation models examining the role of 22 putative mediators on pain or disability, of which 4 had partially mediated treatment effect; 8 had mixed results, and 10 did not mediate treatment effect. The conditions studied were chronic whiplash-associated pain, chronic low back pain, chronic knee pain, and mixed group of chronic primary musculoskeletal pain.

DISCUSSION

We observed that several of the studies included in our systematic review identified similar mechanisms of action, even between different interventions and conditions. However, methodological limitations were common. In conclusion, there are still substantial gaps with respect to understanding how cognitive-behavioral, mind-body, and exercise-based interventions work to reduce pain and disability in people with chronic primary musculoskeletal pain.

Treatment for Pediatric Functional Abdominal Pain: An Initial Examination of Reciprocal Associations Between Pain, Functional Impairment, and Parental Distress

OBJECTIVE

While cross-sectional studies underline that child and parent factors in pediatric chronic pain are reciprocally related, so far, little is known on their prospective relationship, especially in treatment contexts. This study aims to analyze directions of influence between child and parental outcomes using data from an intervention study.

METHODS

The sample covered 109 families with children aged 7-13 years diagnosed with functional abdominal pain (FAP). Child outcomes included pain and impairment, and parental outcomes covered caregiver-specific distress including both parental personal time burden (i.e., less time available for personal needs) and emotional burden due to child's pain (i.e., increased worries). Cross-lagged panel analyses examined the directions of the relations between child and parental outcomes across time (pretreatment T1, post-treatment T2, and 3-month follow-up and 12-month follow-up T3/T4).

RESULTS

First, a significant improvement over time in all measures was observed. Cross-lagged effects were found for less parental personal time burden at T2, predicting both less pain (β = -0.254, p = .004) and less impairment (β = -0.150, p = .039) at T3. Higher baseline pain was predictive for higher parental emotional burden after treatment (β = -0.130, p = .049) and, reversely, for less emotional burden at 12-month follow-up (β = 0.261, p = .004).

CONCLUSIONS

Addressing parental personal time burden in FAP treatment might possibly support the improvement on the child level. Replication of results in larger samples is warranted to gain more insight into the directions of influence and, in that way, to optimize treatment for pediatric FAP.

Cognitive Change and Relaxation as Key Mechanisms of Treatment Outcome in Chronic Pain: Evidence From Routine Care

Despite effective treatment approaches within the cognitive behavioral framework general treatment effects for chronic pain are rather small to very small. Translation from efficacy trials to naturalistic settings is questionable. There is an urgent need to improve the effectiveness of well-established treatments, such as cognitive-behavior therapy (CBT) and the investigation of mechanisms of change is a promising opportunity. We performed secondary data analysis from routine data of 1,440 chronic pain patients. Patients received CBT in a multidisciplinary setting in two inpatient clinics. Effect sizes and reliable change indices were computed for pain-related disability and depression. The associations between changes in the use of different pain coping skills (cognitive restructuring, activity despite pain, relaxation techniques and mental distraction) and changes in clinical outcomes were analyzed in structural equation models. Pre-post effect sizes range from g = 0.47 (disability) to g = 0.89 (depression). Changes in the use of cognitive restructuring, relaxation and to a lesser degree mental distraction were associated with changes in disability and depression. Effects from randomized trials can be translated to naturalistic settings. The results complement experimental research on mechanisms of change in the treatment of chronic pain and indicate an important role of cognitive change and relaxation as mechanisms of change. Our findings cautiously suggest that clinicians should optimize these processes in chronic pain patients to reduce their physical and emotional disability.

Self-management for chronic widespread pain including fibromyalgia: A systematic review and meta-analysis

BACKGROUND

Chronic widespread pain (CWP) including fibromyalgia has a prevalence of up to 15% and is associated with substantial morbidity. Supporting psychosocial and behavioural self-management is increasingly important for CWP, as pharmacological interventions show limited benefit. We systematically reviewed the effectiveness of interventions applying self-management principles for CWP including fibromyalgia.

METHODS

MEDLINE, Embase, PsycINFO, The Cochrane Central Register of Controlled Trials and the WHO International Clinical Trials Registry were searched for studies reporting randomised controlled trials of interventions adhering to self-management principles for CWP including fibromyalgia. Primary outcomes included physical function and pain intensity. Where data were sufficient, meta-analysis was conducted using a random effects model. Studies were narratively reviewed where meta-analysis could not be conducted Evidence quality was rated using GRADE (Grading of Recommendations, Assessment, Development and Evaluations) (PROSPERO-CRD42018099212).

RESULTS

Thirty-nine completed studies were included. Despite some variability in studies narratively reviewed, in studies meta-analysed self-management interventions improved physical function in the short-term, post-treatment to 3 months (SMD 0.42, 95% CI 0.20, 0.64) and long-term, post 6 months (SMD 0.36, 95% CI 0.20, 0.53), compared to no treatment/usual care controls. Studies reporting on pain narratively had greater variability, however, those studies meta-analysed showed self-management interventions reduced pain in the short-term (SMD -0.49, 95% CI -0.70, -0.27) and long-term (SMD -0.38, 95% CI -0.58, -0.19) compared to no treatment/usual care. There were few differences in physical function and pain when self-management interventions were compared to active interventions. The quality of the evidence was rated as low.

CONCLUSION

Reviewed studies suggest self-management interventions can be effective in improving physical function and reducing pain in the short and long-term for CWP including fibromyalgia. However, the quality of evidence was low. Future research should address quality issues whilst making greater use of theory and patient involvement to understand reported variability.

The Development of Mindful-Based Dance Movement Therapy Intervention for Chronic Pain: A Pilot Study With Chronic Headache Patients

Chronic pain is of significant global concern. There is growing evidence that body–mind therapies and psychological approaches can contribute toward changing chronic pain perceptions. This is the first model described in the literature that combines a mindfulness-based approach with dance movement therapy and explores the potential psychological and pain-related changes for this client population. In this paper, the results from the pilot study are presented involving patients with chronic headache recruited in an outpatient rehabilitation setting.

Methods: In this pilot study, 29 patients (n = 29) with chronic headache were randomized to either the Mindful-Based Dance Movement Therapy (MBDMT) group or the waiting list control group (treatment as usual, TAU). The MBDMT group was offered 10 sessions in a clinical outpatient rehabilitation setting for 5 weeks. Data were collected pre- and post-intervention and 16 weeks after the intervention was finished. The Hospital Anxiety and Depression Scale (HADS), Patient Health Questionnaire−9 (PHQ-9), Five Facet Mindfulness Questionnaire (FFMQ), and Numeric Rating Scale (NRS) were used as outcome measures.

Results: The working model of MBDMT identifies nine therapeutic mechanisms (safe therapeutic environment, mindfulness skills, body awareness, relaxation/releasing, distancing and staying with discomfort, meaning making, self-regulation, acceptance and integration, creative process). Per-protocol analysis reveals statistically significant reduction of pain intensity and depression scores in favor of the MBDMT group, and these improvements were maintained in the follow-up assessment.

Conclusions: The results suggest that MBDMT is a feasible and promising therapy approach for chronic pain patients. The pilot study offered sufficient information and preliminary results in the desirable direction to enable the researchers to move to a randomized controlled trial (RCT) stage in order to establish the efficacy of the intervention.

Clinical Trial Registration: The study was registered in the www.researchregistry.com, registry (5483).

Using Mediation Analysis to Understand How Treatments for Paediatric Pain Work: A Systematic Review and Recommendations for Future Research

Clinicians have an increasing number of evidence-based interventions to treat pain in youth. Mediation analysis offers a way of investigating how interventions work, by examining the extent to which an intermediate variable, or mediator, explains the effect of an intervention. This systematic review examined studies that used mediation analysis to investigate mechanisms of interventions on pain-relevant outcomes for youth (3–18 years) with acute or chronic pain, and provides recommendations for future mediation research in this field. We searched five electronic databases for clinical trials or observational longitudinal studies that included a comparison group and conducted mediation analyses of interventions on youth and assessed pain outcomes. We found six studies (N = 635), which included a total of 53 mediation models examining how interventions affect pain-relevant outcomes for youth. Five studies were secondary analyses of randomized controlled trials of psychological interventions for chronic pain; one was a longitudinal observational study of morphine for acute pain. The pain conditions studied were irritable bowel syndrome, functional abdominal pain, juvenile fibromyalgia, mixed chronic pain, and post-operative pain. Fourteen putative mediators were tested, of which three partially mediated treatment effect; seven did not significantly mediate treatment effect and four had mixed results. Methodological and reporting limitations were common. There are substantial gaps in the field with respect to investigating, and therefore understanding, how paediatric interventions work.

A randomized controlled trial of cognitive behavioral therapy compared with diabetes education for diabetic peripheral neuropathic pain

A randomized controlled trial compared cognitive behavioral therapy (CBT) and diabetes education (ED) as an adjunctive treatment for diabetic peripheral neuropathic pain (DPNP). We examined change from baseline to 12- and 36-week follow-up in overall pain intensity (NRS), neuropathic pain intensity/quality, pain interference, and mental health functioning, among others. Although CBT participants demonstrated improvement in pain intensity NRS, there were no between-condition differences at either follow-up. CBT reduced neuropathic pain intensity at 12-weeks more than ED. At 36-weeks, CBT was superior to ED for improving pain interference and mental health functioning. Results provide evidence of benefit of CBT for DPNP.

ClinicalTrials.gov Identifier: NCT00830011

The mechanisms of effect of a physiotherapist-delivered integrated psychological and exercise intervention for acute whiplash-associated disorders: secondary mediation analysis of a randomized controlled trial

Supplemental Digital Content is Available in the Text. Stress mediated the effect of a physiotherapist-delivered integrated intervention on multiple health outcomes and pain-related coping mediated the effect on pain self-efficacy only. Changes in depressive and posttraumatic stress symptoms were also mechanisms of effect.

Introduction:

Integrated psychological and physical treatments can improve recovery for whiplash-associated disorders (WADs). Little is known about how these interventions work.

Objective:

To examine the mechanisms by which a physiotherapist-delivered integrated intervention for acute WAD improves health outcomes.

Methods:

Secondary analysis using structural equation modelling of a randomized controlled trial comparing integrated stress inoculation training and exercise to exercise alone for acute WAD. Outcomes were disability, pain self-efficacy, pain intensity, and health-related quality of life at 12 months. The intended intervention target and primary mediator, stress was tested in parallel with pain-related coping, an additional cognitive behavioral mediator that significantly improved at posttreatment (Model 1). Stress-related constructs that commonly co-occur with stress and pain were also tested as parallel mediators: depression and pain-related coping (Model 2); and posttraumatic stress and pain-related coping (Model 3).

Results:

Reductions in stress mediated the effect of the integrated intervention on disability (β = −0.12, confidence interval [CI] = −0.21 to −0.06), pain self-efficacy (β = 0.09, CI = 0.02–0.18), pain (β = −0.12, CI = −0.21 to −0.06), and health-related quality of life (β = 0.11, CI = 0.04–0.21). There was an additional path to pain self-efficacy through pain-related coping (β = 0.06, CI = 0.01–0.12). Similar patterns were found in Models 2 and 3.

Conclusions:

Improvements in stress and related constructs of depression and posttraumatic stress, and pain-related coping were causal mechanisms of effect in a physiotherapist-delivered integrated intervention. As integrated interventions are growing in popularity, it is important to further personalize interventions for improved benefit.

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.

Current status of acceptance and commitment therapy for chronic pain: a narrative review

It is well known that chronic pain is prevalent, complex to manage, and associated with high costs, in health care and society in general. Thanks to advances in new forms of cognitive behavioral therapy (known as third-wave CBT), currently clinicians and researchers have an empirically validated psychological treatment with increasing research support for the treatment of chronic pain. This treatment is called acceptance and commitment therapy (ACT). The main aim of this paper is to provide a narrative review that summarizes and integrates the current state of knowledge of ACT in the management of chronic pain as well as discuss current challenges and opportunities for progress. Based on the psychological flexibility model, ACT extends previous forms of CBT and integrates many CBT-related variables into six core therapeutic processes. ACT is a process-based therapy that fosters openness, awareness, and engagement through a wide range of methods, including exposure-based and experiential methods, metaphors, and values clarification. To our knowledge, there are three published systematic reviews and meta-analyses that support the effectiveness of ACT for chronic pain and many studies focused on specific processes derived from the psychological flexibility model. There is also promising support for the cost-effectiveness of ACT; however, the current evidence is still insufficient to establish firm conclusions about cost-effectiveness and the most efficient means of delivery. Additional well-designed economic evaluations are needed. Other research aims include delineating the neurobiological underpinnings of ACT, refining available outcome and process measures or develop new ones for ACT trials, and meeting the challenge of wide dissemination and implementation in real-world clinical practice.

Internet-delivered aftercare following multimodal rehabilitation program for chronic pain: a qualitative feasibility study

Purpose

Methods for delivering aftercare to help chronic pain patients to continue practice self-management skills after rehabilitation are needed. Internet-delivered cognitive behavioral therapy (ICBT) has the potential to partly fill this gap given its accessibility and emphasis on self-care. Methods for engaging and motivating patients to persist throughout the full length of treatment are needed. The aim of this study was to describe how chronic pain patients work in an ICBT program, through their descriptions of what is important when they initiate behavior change in aftercare and their descriptions of what is important for ongoing practice of self-management skills in aftercare.

Patients and methods

Following a multimodal rehabilitation program, 29 chronic pain patients participated in a 20-week-long Internet-delivered aftercare program (ACP) based on acceptance-based cognitive behavioral therapy. Latent content analysis was made on 138 chapters of diary-like texts written by participants in aftercare.

Results

Attitudes regarding pain and body changed during ACP, as did attitudes toward self and the future for some participants. How participants practiced self-management skills was influenced by how they expressed motivation behind treatment goals. Whether they practiced acceptance strategies influenced their continuous self-management practice. Defusion techniques seemed to be helpful in the process of goal setting. Mindfulness strategies seemed to be helpful when setbacks occurred.

Conclusion

Self-motivating goals are described as important both to initiate and in the ongoing practice of self-management skills. Experiencing a helpful effect of acceptance strategies seems to encourage participants to handle obstacles in new ways and to persist throughout treatment. Research on whether tailored therapist guidance might be helpful in stating self-motivating goals and contribute to ongoing practice of self-management skills is needed.

Happy Despite Pain: A Randomized Controlled Trial of an 8-Week Internet-delivered Positive Psychology Intervention for Enhancing Well-being in Patients With Chronic Pain

Supplemental Digital Content is available in the text.

Objectives:

There is preliminary evidence for the efficacy of positive psychology interventions for pain management. The current study examined the effects of an internet-based positive psychology self-help program for patients with chronic musculoskeletal pain and compared it with an internet-based cognitive-behavioral program.

Materials and Methods:

A randomized controlled trial was carried out with 3 conditions: an internet-delivered positive psychology program, an internet-delivered cognitive-behavioral program and waitlist control. A total of 276 patients were randomized to 1 of the 3 conditions and posttreatment data were obtained from 206 patients. Primary outcomes were happiness, depression, and physical impairments at posttreatment and at 6-month follow-up. Intention-to-treat analyses were carried out using mixed regression analyses.

Results:

Both treatments led to significant increases in happiness and decreases in depression. Physical impairments did not significantly decrease compared with waitlist. Improvements in happiness and depression were maintained until 6-month follow-up. There were no overall differences in the efficacy of the 2 active interventions but effects seemed to be moderated by education. Patients with a higher level of education profited slightly more from the positive psychology intervention than from the cognitive-behavioral program.

Discussion:

The results suggest that an internet-based positive psychology and cognitive-behavioral self-help interventions for the management of chronic pain are clinically useful. Because the self-help exercises as used in the current program do not require therapist involvement, dissemination potential is large. Further studies should examine whether it can best be used as stand-alone or add-on treatment combined with established pain treatment programs.

Causal mechanisms in the clinical course and treatment of back pain

In recent years, there has been increasing interest in studying causal mechanisms in the development and treatment of back pain. The aim of this article is to provide an overview of our current understanding of causal mechanisms in the field. In the first section, we introduce key concepts and terminology. In the second section, we provide a brief synopsis of systematic reviews of mechanism studies relevant to the clinical course and treatment of back pain. In the third section, we reflect on the findings of our review to explain how understanding causal mechanisms can inform clinical practice and the implementation of best practice. In the final sections, we introduce contemporary methodological advances, highlight the key assumptions of these methods, and discuss future directions to advance the quality of mechanism-related studies in the back pain field.

Advancing psychological therapies for chronic pain

There is a strong tradition of therapy development and evaluation in the field of psychological interventions for chronic pain. However, despite this research production, the effects of treatments remain uncertain, and treatment development has stalled. This review summarises the current evidence but focusses on promising areas for improvement. Advancing psychological therapies for chronic pain will come from a radical re-imagining of the content, delivery, place, and control of therapy. The next generation of therapeutic interventions will also need alternative methods of measurement and evaluation, and options are discussed.