Narrative bias ("spin") is common in randomised trials and systematic reviews of cannabinoids for pain

ABSTRACT

We define narrative bias as a tendency to interpret information as part of a larger story or pattern, regardless of whether the facts support the full narrative. Narrative bias in title and abstract means that results reported in the title and abstract of an article are done so in a way that could distort their interpretation and mislead readers who had not read the whole article. Narrative bias is often referred to as "spin." It is prevalent in abstracts of scientific papers and is impactful because abstracts are often the only part of an article read. We found no extant narrative bias instrument suitable for exploring both efficacy and safety statements in randomized trials and systematic reviews of pain. We constructed a 6-point instrument with clear instructions and tested it on randomised trials and systematic reviews of cannabinoids and cannabis-based medicines for pain, with updated searches to April 2021. The instrument detected moderate or severe narrative bias in the title and abstract of 24% (8 of 34) of randomised controlled trials and 17% (11 of 64) of systematic reviews; narrative bias for efficacy and safety occurred equally. There was no significant or meaningful association between narrative bias and study characteristics in correlation or cluster analyses. Bias was always in favour of the experimental cannabinoid or cannabis-based medicine. Put simply, reading title and abstract only could give an incorrect impression of efficacy or safety in about 1 in 5 papers reporting on these products.

Reframing pain: the power of individual and societal factors to enhance pain treatment

The effectiveness of analgesics can be increased if synergistic behavioural, psychological, and pharmacological interventions are provided within a supportive environment.

Updated recommendations on measures for clinical trials in pediatric chronic pain: a multiphase approach from the Core Outcomes in Pediatric Persistent Pain (Core-OPPP) Workgroup

ABSTRACT

Many gaps remain in finding effective, safe, and equitable treatments for children and adolescents with chronic pain and in accessing treatments in different settings. A major goal of the field is to improve assessment of pain and related experience. Valid and reliable patient-reported outcome measures are critical for advancing knowledge of clinical interventions for pediatric chronic pain. Building on the work of the Ped-IMMPACT group, we previously updated a core outcome set (COS) for pediatric chronic pain clinical trials using stakeholder feedback from providers, youth, and parents. The new COS includes 3 mandatory domains: pain severity, pain-related interference with daily living, and adverse events and 4 optional domains: overall well-being, emotional functioning, physical functioning, and sleep quality. The aim of this study was to use a multiphased approach to recommend specific measures for each of the 7 domains identified in our new COS for pediatric chronic pain. We synthesized evidence through conducting the following: (1) a Delphi study of experts to identify candidate measures for the new COS domains, (2) a review phase to gather evidence for measurement properties for candidate measures, and (3) an expert consensus conference to reach agreement on measurement recommendations. Final recommendations included 9 patient-reported measures. Important contextual considerations are discussed, and guidance is provided regarding strengths and limitations of the recommendations. Implementation of these recommendations may be enhanced by widespread dissemination and ease of access to measurement tools.

Cannabidiol (CBD) Products for Pain: Ineffective, Expensive, and With Potential Harms

Cannabidiol (CBD) attracts considerable attention for promoting good health and treating various conditions, predominantly pain, often in breach of advertising rules. Examination of available CBD products in North America and Europe demonstrates that CBD content can vary from none to much more than advertised and that potentially harmful other chemicals are often included. Serious harm is associated with chemicals found in CBD products and reported in children, adults, and the elderly. A 2021 International Association for the Study of Pain task force examined the evidence for cannabinoids and pain but found no trials of CBD. Sixteen CBD randomized trials using pharmaceutical-supplied CBD or making preparations from such a source and with pain as an outcome have been published subsequently. The trials were conducted in 12 different pain states, using 3 oral, topical, and buccal/sublingual administration, with CBD doses between 6 and 1,600 mg, and durations of treatment between a single dose and 12 weeks. Fifteen of the 16 showed no benefit of CBD over placebo. Small clinical trials using verified CBD suggest the drug to be largely benign; while large-scale evidence of safety is lacking, there is growing evidence linking CBD to increased rates of serious adverse events and hepatotoxicity. In January 2023, the Food and Drug Administration (FDA) announced that a new regulatory pathway for CBD was needed. Consumers and health care providers should rely on evidence-based sources of information on CBD, not just advertisements. Current evidence is that CBD for pain is expensive, ineffective, and possibly harmful. PERSPECTIVE: There is no good reason for thinking that CBD relieves pain, but there are good reasons for doubting the contents of CBD products in terms of CBD content and purity.

The STAR care pathway for patients with chronic pain after total knee replacement: four-year follow-up of a randomised controlled trial

BACKGROUND

The Support and Treatment After Replacement (STAR) care pathway is a clinically important and cost-effective intervention found to improve pain outcomes over one year for people with chronic pain three months after total knee replacement (TKR). We followed up STAR trial participants to evaluate the longer-term clinical- and cost-effectiveness of this care pathway.

METHODS

Participants who remained enrolled on the trial at one year were contacted by post at a median of four years after randomisation and invited to complete a questionnaire comprising the same outcomes collected during the trial. We captured pain (co-primary outcome using the Brief Pain Inventory (BPI) pain severity and interference scales; scored 0-10, best to worst), function, neuropathic characteristics, emotional aspects of pain, health-related quality of life, and satisfaction. Electronic hospital informatics data on hospital resource use for the period of one to four years post-randomisation were collected from participating hospital sites. The economic evaluation took an National Health Service (NHS) secondary care perspective, with a four-year time horizon.

RESULTS

Overall, 226/337 (67%) of participants returned completed follow-up questionnaires, yielding adjusted between-group differences in BPI means of -0.42 (95% confidence interval, CI (-1.07, 0.23); p = 0.20) for pain severity and - 0.64 (95% CI -1.41, 0.12); p = 0.10) for pain interference. Analysis using a multiple imputed data set (n = 337) showed an incremental net monetary benefit in favour of the STAR care pathway of £3,525 (95% CI -£990 to £8,039) at a £20,000/QALY willingness-to-pay threshold, leading to a probability that the intervention was cost-effective of 0.94.

CONCLUSIONS

The magnitude of the longer-term benefits of the STAR care pathway are uncertain due to attrition of trial participants; however, there is a suggestion of some degree of sustained clinical benefit at four years. The care pathway remained cost-effective at four years.

TRIAL REGISTRATION

ISRCTN: 92,545,361.

Trials We Cannot Trust: Investigating Their Impact on Systematic Reviews and Clinical Guidelines in Spinal Pain

We previously conducted an exploration of the trustworthiness of a group of clinical trials of cognitive-behavioral therapy and exercise in spinal pain. We identified multiple concerns in 8 trials, judging them untrustworthy. In this study, we systematically explored the impact of these trials ("index trials") on results, conclusions, and recommendations of systematic reviews and clinical practice guidelines (CPGs). We conducted forward citation tracking using Google Scholar and the citationchaser tool, searched the Guidelines International Network library and National Institute of Health and Care Excellence archive to June 2022 to identify systematic reviews and CPGs. We explored how index trials impacted their findings. Where reviews presented meta-analyses, we extracted or conducted sensitivity analyses for the outcomes of pain and disability, to explore how the exclusion of index trials affected effect estimates. We developed and applied an 'Impact Index' to categorize the extent to which index studies impacted their results. We included 32 unique reviews and 10 CPGs. None directly raised concerns regarding the veracity of the trials. Across meta-analyses (55 comparisons), the removal of index trials reduced effect sizes by a median of 58% (Inter Quartlie Range (IQR) 40-74). 85% of comparisons were classified as highly, 3% as moderately, and 11% as minimally impacted. Nine out of 10 reviews conducting narrative synthesis drew positive conclusions regarding the intervention tested. Nine out of 10 CPGs made positive recommendations for the intervention(s) evaluated. This cohort of trials, with concerns regarding trustworthiness, has substantially impacted the results of systematic reviews and guideline recommendations. PERSPECTIVE: We found that a group of trials of CBT for spinal pain with concerns relating to their trustworthiness has had substantial impacts on the analyses and conclusions of systematic reviews and clinical practice guidelines. This highlights the need for a greater focus on the trustworthiness of studies in evidence appraisal. PRE-REGISTRATION: Our protocol was preregistered on the Open Science Framework: https://osf.io/m92ax/.

Characteristics of retracted publications related to pain research: a systematic review

ABSTRACT

Retraction is a mechanism for correcting the scientific record and alerts readers when a study contains unreliable or flawed data. Such data may arise from error or research misconduct. Studies examining the landscape of retracted publications provide insight into the extent of unreliable data and its effect on a medical discipline. We aimed to explore the extent and characteristics of retracted publications in pain research. We searched the EMBASE, PubMed, CINAHL, PsycINFO, and Retraction Watch databases to December 31, 2022. We included retracted articles that (1) investigated mechanisms of painful conditions, (2) tested treatments that aimed to reduce pain, or (3) measured pain as an outcome. Descriptive statistics were used to summarise the included data. We included 389 pain articles published between 1993 and 2022 and retracted between 1996 and 2022. There was a significant upward trend in the number of retracted pain articles over time. Sixty-six percent of articles were retracted for reasons relating to misconduct. The median (interquartile range) time from article publication to retraction was 2 years (0.7-4.3). The time to retraction differed by reason for retraction, with data problems, comprising data falsification, duplication, and plagiarism, resulting in the longest interval (3 [1.2-5.2] years). Further investigations of retracted pain articles, including exploration of their fate postretraction, are necessary to determine the impact of unreliable data on pain research.

Co-occurring chronic pain and primary psychological disorders in adolescents: A scoping review

Long-term health conditions, whether mental or physical, often co-occur in adolescents. For instance, adolescents with chronic pain may experience co-occurring primary psychological disorders. In this scoping review, we determine the influence of co-occurring chronic pain and primary psychological disorders on adolescents' functioning. A systematic search of six databases was conducted to identify articles if they were: (1) peer-reviewed; (2) reported original findings; (3) included participants aged 11-19 years, who experienced chronic pain (i.e., pain lasting 3 months or more) and had a co-occurring diagnosis of a primary psychological disorder; and (4) assessed functioning. Searches returned 9864 articles after the removal of duplicates. A two-phase abstract and full-text screening process identified two eligible articles which compared emotional functioning (n = 1) and social functioning (n = 2) between groups of adolescents with co-occurring chronic pain and primary psychological disorders with adolescents only reporting chronic pain. Overall findings revealed no differences in social functioning, but adolescents with co-occurring chronic pain and a primary psychological disorder (depression and anxiety) reported worse emotional functioning compared with adolescents with chronic pain alone. This review confirms the limited research on the co-occurrence of primary psychological disorders and chronic pain in adolescents by only identifying two eligible articles exploring the co-occurrence of chronic pain with depression, anxiety, and/or attentional disorders.

Psychological therapies delivered remotely for the management of chronic pain (excluding headache) in adults

BACKGROUND

Chronic pain (pain lasting three months or more) is an unpleasant sensory and emotional experience associated with actual or potential tissue damage. Common types (excluding headache) include back pain, fibromyalgia, and neuropathic pain. Access to traditional face-to-face therapies can be restricted by healthcare resources, geography, and cost. Remote technology-based delivery of psychological therapies has the potential to overcome treatment barriers. However, their therapeutic effectiveness compared to traditional delivery methods requires further investigation.

OBJECTIVES

To determine the benefits and harms of remotely-delivered psychological therapies compared to active control, waiting list, or treatment as usual for the management of chronic pain in adults.

SEARCH METHODS

We searched for randomised controlled trials (RCTs) in CENTRAL, MEDLINE, Embase, and PsycINFO to 29 June 2022. We also searched clinical trials registers and reference lists. We conducted a citation search of included trials to identify any further eligible trials.

SELECTION CRITERIA

We included RCTs in adults (≥ 18 years old) with chronic pain. Interventions included psychological therapies with recognisable psychotherapeutic content or based on psychological theory. Trials had to have delivered therapy remote from the therapist (e.g. Internet, smartphone application) and involve no more than 30% contact time with a clinician. Comparators included treatment as usual (including waiting-list controls) and active controls (e.g. education).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures.

MAIN RESULTS

We included 32 trials (4924 participants) in the analyses. Twenty-five studies delivered cognitive behavioural therapy (CBT) to participants, and seven delivered acceptance and commitment therapy (ACT). Participants had back pain, musculoskeletal pain, opioid-treated chronic pain, mixed chronic pain, hip or knee osteoarthritis, spinal cord injury, fibromyalgia, provoked vestibulodynia, or rheumatoid arthritis. We assessed 25 studies as having an unclear or high risk of bias for selective reporting. However, across studies overall, risk of bias was generally low. We downgraded evidence certainty for primary outcomes for inconsistency, imprecision, and study limitations. Certainty of evidence ranged from moderate to very low. Adverse events were inadequately reported or recorded across studies. We report results only for studies in CBT here. Cognitive behavioural therapy (CBT) versus treatment as usual (TAU) Pain intensity Immediately after treatment, CBT likely demonstrates a small beneficial effect compared to TAU (standardised mean difference (SMD) -0.28, 95% confidence interval (CI) -0.39 to -0.16; 20 studies, 3206 participants; moderate-certainty evidence). Participants receiving CBT are probably more likely to achieve a 30% improvement in pain intensity compared to TAU (23% versus 11%; risk ratio (RR) 2.15, 95% CI 1.62 to 2.85; 5 studies, 1347 participants; moderate-certainty evidence). They may also be more likely to achieve a 50% improvement in pain intensity (6% versus 2%; RR 2.31, 95% CI 1.14 to 4.66; 4 studies, 1229 participants), but the evidence is of low certainty. At follow-up, there is likely little to no difference in pain intensity between CBT and TAU (SMD -0.04, 95% CI -0.17 to 0.09; 8 studies, 959 participants; moderate-certainty evidence). The evidence comparing CBT to TAU on achieving a 30% improvement in pain is very uncertain (40% versus 24%; RR 1.70, 95% CI 0.82 to 3.53; 1 study, 69 participants). No evidence was available regarding a 50% improvement in pain. Functional disability Immediately after treatment, CBT may demonstrate a small beneficial improvement compared to TAU (SMD -0.38, 95% CI -0.53 to -0.22; 14 studies, 2672 participants; low-certainty evidence). At follow-up, there is likely little to no difference between treatments (SMD -0.05, 95% CI -0.23 to 0.14; 3 studies, 461 participants; moderate-certainty evidence). Quality of life Immediately after treatment, CBT may not have resulted in a beneficial effect on quality of life compared to TAU, but the evidence is very uncertain (SMD -0.16, 95% CI -0.43 to 0.11; 7 studies, 1423 participants). There is likely little to no difference between CBT and TAU on quality of life at follow-up (SMD -0.16, 95% CI -0.37 to 0.05; 3 studies, 352 participants; moderate-certainty evidence). Adverse events Immediately after treatment, evidence about the number of people experiencing adverse events is very uncertain (34% in TAU versus 6% in CBT; RR 6.00, 95% CI 2.2 to 16.40; 1 study, 140 participants). No evidence was available at follow-up. Cognitive behavioural therapy (CBT) versus active control Pain intensity Immediately after treatment, CBT likely demonstrates a small beneficial effect compared to active control (SMD -0.28, 95% CI -0.52 to -0.04; 3 studies, 261 participants; moderate-certainty evidence). The evidence at follow-up is very uncertain (mean difference (MD) 0.50, 95% CI -0.30 to 1.30; 1 study, 127 participants). No evidence was available for a 30% or 50% pain intensity improvement. Functional disability Immediately after treatment, there may be little to no difference between CBT and active control on functional disability (SMD -0.26, 95% CI -0.55 to 0.02; 2 studies, 189 participants; low-certainty evidence). The evidence at follow-up is very uncertain (MD 3.40, 95% CI -1.15 to 7.95; 1 study, 127 participants). Quality of life Immediately after treatment, there is likely little to no difference in CBT and active control (SMD -0.22, 95% CI -1.11 to 0.66; 3 studies, 261 participants; moderate-certainty evidence). The evidence at follow-up is very uncertain (MD 0.00, 95% CI -0.06 to 0.06; 1 study, 127 participants). Adverse events Immediately after treatment, the evidence comparing CBT to active control is very uncertain (2% versus 0%; RR 3.23, 95% CI 0.13 to 77.84; 1 study, 135 participants). No evidence was available at follow-up.

AUTHORS' CONCLUSIONS

Currently, evidence about remotely-delivered psychological therapies is largely limited to Internet-based delivery of CBT. We found evidence that remotely-delivered CBT has small benefits for pain intensity (moderate certainty) and functional disability (moderate to low certainty) in adults experiencing chronic pain. Benefits were not maintained at follow-up. Our appraisal of quality of life and adverse events outcomes post-treatment were limited by study numbers, evidence certainty, or both. We found limited research (mostly low to very low certainty) exploring other psychological therapies (i.e. ACT). More high-quality studies are needed to assess the broad translatability of psychological therapies to remote delivery, the different delivery technologies, treatment longevity, comparison with active control, and adverse events.

Antidepressants for pain management in adults with chronic pain: a network meta-analysis

BACKGROUND

Chronic pain is common in adults, and often has a detrimental impact upon physical ability, well-being, and quality of life. Previous reviews have shown that certain antidepressants may be effective in reducing pain with some benefit in improving patients' global impression of change for certain chronic pain conditions. However, there has not been a network meta-analysis (NMA) examining all antidepressants across all chronic pain conditions.

OBJECTIVES

To assess the comparative efficacy and safety of antidepressants for adults with chronic pain (except headache).

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, LILACS, AMED and PsycINFO databases, and clinical trials registries, for randomised controlled trials (RCTs) of antidepressants for chronic pain conditions in January 2022.

SELECTION CRITERIA

We included RCTs that examined antidepressants for chronic pain against any comparator. If the comparator was placebo, another medication, another antidepressant, or the same antidepressant at different doses, then we required the study to be double-blind. We included RCTs with active comparators that were unable to be double-blinded (e.g. psychotherapy) but rated them as high risk of bias. We excluded RCTs where the follow-up was less than two weeks and those with fewer than 10 participants in each arm.  DATA COLLECTION AND ANALYSIS: Two review authors separately screened, data extracted, and judged risk of bias. We synthesised the data using Bayesian NMA and pairwise meta-analyses for each outcome and ranked the antidepressants in terms of their effectiveness using the surface under the cumulative ranking curve (SUCRA). We primarily used Confidence in Meta-Analysis (CINeMA) and Risk of Bias due to Missing Evidence in Network meta-analysis (ROB-MEN) to assess the certainty of the evidence. Where it was not possible to use CINeMA and ROB-MEN due to the complexity of the networks, we used GRADE to assess the certainty of the evidence. Our primary outcomes were substantial (50%) pain relief, pain intensity, mood, and adverse events. Our secondary outcomes were moderate pain relief (30%), physical function, sleep, quality of life, Patient Global Impression of Change (PGIC), serious adverse events, and withdrawal.

MAIN RESULTS

This review and NMA included 176 studies with a total of 28,664 participants. The majority of studies were placebo-controlled (83), and parallel-armed (141). The most common pain conditions examined were fibromyalgia (59 studies); neuropathic pain (49 studies) and musculoskeletal pain (40 studies). The average length of RCTs was 10 weeks. Seven studies provided no useable data and were omitted from the NMA. The majority of studies measured short-term outcomes only and excluded people with low mood and other mental health conditions. Across efficacy outcomes, duloxetine was consistently the highest-ranked antidepressant with moderate- to high-certainty evidence. In duloxetine studies, standard dose was equally efficacious as high dose for the majority of outcomes. Milnacipran was often ranked as the next most efficacious antidepressant, although the certainty of evidence was lower than that of duloxetine. There was insufficient evidence to draw robust conclusions for the efficacy and safety of any other antidepressant for chronic pain.  Primary efficacy outcomes Duloxetine standard dose (60 mg) showed a small to moderate effect for substantial pain relief (odds ratio (OR) 1.91, 95% confidence interval (CI) 1.69 to 2.17; 16 studies, 4490 participants; moderate-certainty evidence) and continuous pain intensity (standardised mean difference (SMD) -0.31, 95% CI -0.39 to -0.24; 18 studies, 4959 participants; moderate-certainty evidence). For pain intensity, milnacipran standard dose (100 mg) also showed a small effect (SMD -0.22, 95% CI -0.39 to 0.06; 4 studies, 1866 participants; moderate-certainty evidence). Mirtazapine (30 mg) had a moderate effect on mood (SMD -0.5, 95% CI -0.78 to -0.22; 1 study, 406 participants; low-certainty evidence), while duloxetine showed a small effect (SMD -0.16, 95% CI -0.22 to -0.1; 26 studies, 7952 participants; moderate-certainty evidence); however it is important to note that most studies excluded participants with mental health conditions, and so average anxiety and depression scores tended to be in the 'normal' or 'subclinical' ranges at baseline already. Secondary efficacy outcomes Across all secondary efficacy outcomes (moderate pain relief, physical function, sleep, quality of life, and PGIC), duloxetine and milnacipran were the highest-ranked antidepressants with moderate-certainty evidence, although effects were small. For both duloxetine and milnacipran, standard doses were as efficacious as high doses. Safety There was very low-certainty evidence for all safety outcomes (adverse events, serious adverse events, and withdrawal) across all antidepressants. We cannot draw any reliable conclusions from the NMAs for these outcomes.

AUTHORS' CONCLUSIONS

Our review and NMAs show that despite studies investigating 25 different antidepressants, the only antidepressant we are certain about for the treatment of chronic pain is duloxetine. Duloxetine was moderately efficacious across all outcomes at standard dose. There is also promising evidence for milnacipran, although further high-quality research is needed to be confident in these conclusions. Evidence for all other antidepressants was low certainty. As RCTs excluded people with low mood, we were unable to establish the effects of antidepressants for people with chronic pain and depression. There is currently no reliable evidence for the long-term efficacy of any antidepressant, and no reliable evidence for the safety of antidepressants for chronic pain at any time point.

Flawed, futile, and fabricated-features that limit confidence in clinical research in pain and anaesthesia: a narrative review

The randomised controlled trial is the foundation of clinical research; yet there is concern that many trials have flaws in design, conduct, and reporting that undermine trustworthiness. Common flaws in trials include high risk of bias, small size, outcomes irrelevant to clinical care and patient's experience, and inability to detect efficacy even if present. These flaws carry forward into systematic reviews, which can confer the label of 'high-quality evidence' on inadequate data. Trials can be futile because their flaws mean that they cannot deliver any meaningful result in that different results in a small number of patients would be sufficient to change conclusions. Some trials have been discovered to be fabricated, the number of which is growing. The fields of anaesthesia and pain have more fabricated trials than other clinical fields, possibly because of increased vigilance. This narrative review examines these themes in depth whilst acknowledging an inescapable conclusion: that much of our clinical evidence is in trouble, and special measures are needed to bolster quality and confidence.

[Psychological aspects of pain prevention : German version]

How to prevent the onset, maintenance, or exacerbation of pain is a major focus of clinical pain science. Pain prevention can be distinctly organised into primary, secondary, and tertiary prevention. Primary prevention describes avoiding hurt or pain, secondary prevention describes reducing pain when pain is unavoidable, and tertiary prevention describes preventing or reducing ongoing negative consequences such as high functional disability or distress due to chronic pain. Each poses separate challenges where unique psychological factors will play a role. In this short review article, we highlight psychological factors important to primary, secondary, and tertiary prevention and provide direction for the field. We present 2 case studies on secondary prevention in children and adolescents and tertiary prevention in adults with chronic pain. Finally, we provide research directions for progression in this field, highlighting the importance of clear theoretical direction, the identification of risk factors for those most likely to develop pain, and the importance of treatment.

Body movement as a biomarker for use in chronic pain rehabilitation: An embedded analysis of an RCT of a virtual reality solution for adults with chronic pain

Introduction

Chronic low back pain (CLBP) is a major public health problem. Reliably measuring the effects of chronic pain on movement and activity, and any changes due to treatment, is a healthcare challenge. A recently published paper demonstrated that a novel digital therapeutic (DTxP) was efficacious in reducing fear of movement and increasing the quality of life of adult patients with moderate to severe CLBP. In this paper, we report a study of how data from wearable devices collected in this study could be used as a digital measure for use in studies of chronic low back pain.

Methods

Movement, electrodermal recording, general activity and clinical assessment data were collected in a clinical trial of a novel digital therapeutic intervention (DTxP) by using the sensors in commercial Garmin Vivosmart 4, Empatica Embrace2 and Oculus Quest wearables. Wearable data were collected during and between the study interventions (frequent treatment sessions of DTxP). Data were analyzed using exploratory statistical analysis.

Results

A pattern of increased longitudinal velocity in the movement data collected with right-hand, left-hand, and head sensors was observed in the study population. Correlations were observed with the changes in clinical scales (Tampa Scale of Kinesiophobia, EQ5D Overall health VAS, and EQ5D QoL score). The strongest correlation was observed with the increased velocity of head and right-hand sensors (Spearman correlation with increasing head sensor velocity and Tampa Scale of Kinesiophobia -0.45, Overall health VAS +0.67 and EQ5D QoL score -0.66). The sample size limited interpretation of electrodermal and general activity data.

Discussion/Conclusion

We found a novel digital signal for use in monitoring the efficacy of a digital therapeutics (DTxP) in adults with CLBP. We discuss the potential use of such movement based digital markers as surrogate or additional endpoints in studies of chronic musculoskeletal pain.

Clinical Trial Registration

https://clinicaltrials.gov/ct2/show/NCT04225884?cond=NCT04225884&draw=2&rank=1, identifier: NCT04225884.

The sands of time: Adolescents' temporal perceptions of peer relationships and autonomy in the context of living with chronic pain

The incidence of chronic and recurrent pain increases in adolescence. Prevalence of adolescent chronic pain is estimated to be 11%‐44%, with approximately 5% adolescents experiencing moderate‐to‐severe chronic pain. Adolescents with chronic pain also report unwanted changes in emotional, social, and developmental functioning. Very little is known about how adolescents with chronic pain make sense of their development, the role of pain in that development, and how such developmental trajectories progress over time. A multi‐methods qualitative study was designed to explore how adolescents make sense of their experience of chronic pain in the context of development. Nine adolescents (8 girls) aged 12‐22 years old (Mean = 15.7, SD = 2.8) were recruited from a UK national pain service. Adolescents completed an interview on entering the service, and a follow‐up interview 12 months later. They also completed monthly diaries in this 12‐month period. Data comprised 18 interviews and 60 diary entries, which were analyzed using inductive reflexive thematic analysis. Analyses generated one overarching theme entitled “tug of war: push and pull,” demonstrating developmental tension related to pain, and the cumulative impact these had over time. This overarching theme comprised two subthemes which capture these tensions across the developmental domains of peer relationships and autonomy. The first subtheme, “the shifting sands of peer relationships,” explores the ever‐changing closeness between self and peers. The second subtheme referred to “restricted choices” and how pain limited the participants' autonomy but that this, over time could push development forward. These results extend previous cross‐sectional research on the developmental consequences of chronic pain, showing the dynamic fluctuations and alterations to developmental trajectories over time.

A prospective, double-blind, pilot, randomized, controlled trial of an "embodied" virtual reality intervention for adults with low back pain

ABSTRACT

Adults with chronic low back pain, disability, moderate-to-severe pain, and high fear of movement and reinjury were recruited into a trial of a novel, automated, digital therapeutics, virtual reality, psychological intervention for pain (DTxP). We conducted a 3-arm, prospective, double-blind, pilot, randomized, controlled trial comparing DTxP with a sham placebo comparator and an open-label standard care. Participants were enrolled for 6 to 8 weeks, after which, the standard care control arm were rerandomized to receive either the DTxP or sham placebo. Forty-two participants completed assessments at baseline, immediately posttreatment (6-8 weeks), 9-week, and 5-month follow-up. We found that participants in the DTxP group reported greater reductions in fear of movement and better global impression of change when compared with sham placebo and standard care post treatment. No other group differences were noted at posttreatment or follow-up. When compared with baseline, participants in the DTxP group reported lower disability at 5-month follow-up, lower pain interference and fear of movement post treatment and follow-up, and lower pain intensity at posttreatment. The sham placebo group also reported lower disability and fear of movement at 5-month follow-up compared with baseline. Standard care did not report any significant changes. There were a number of adverse events, with one participant reporting a serious adverse event in the sham placebo, which was not related to treatment. No substantial changes in medications were noted, and participants in the DTxP group reported positive gaming experiences.

Benefit-risk assessment and reporting in clinical trials of chronic pain treatments: IMMPACT recommendations

ABSTRACT

Chronic pain clinical trials have historically assessed benefit and risk outcomes separately. However, a growing body of research suggests that a composite metric that accounts for benefit and risk in relation to each other can provide valuable insights into the effects of different treatments. Researchers and regulators have developed a variety of benefit-risk composite metrics, although the extent to which these methods apply to randomized clinical trials (RCTs) of chronic pain has not been evaluated in the published literature. This article was motivated by an Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials consensus meeting and is based on the expert opinion of those who attended. In addition, a review of the benefit-risk assessment tools used in published chronic pain RCTs or highlighted by key professional organizations (ie, Cochrane, European Medicines Agency, Outcome Measures in Rheumatology, and U.S. Food and Drug Administration) was completed. Overall, the review found that benefit-risk metrics are not commonly used in RCTs of chronic pain despite the availability of published methods. A primary recommendation is that composite metrics of benefit-risk should be combined at the level of the individual patient, when possible, in addition to the benefit-risk assessment at the treatment group level. Both levels of analysis (individual and group) can provide valuable insights into the relationship between benefits and risks associated with specific treatments across different patient subpopulations. The systematic assessment of benefit-risk in clinical trials has the potential to enhance the clinical meaningfulness of RCT results.

Experiences of recovery and a new care pathway for people with pain after total knee replacement: qualitative research embedded in the STAR trial

Background

Approximately 20% of people experience chronic postsurgical pain after total knee replacement. The STAR randomised controlled trial (ISCRTN92545361) evaluated the clinical- and cost-effectiveness of a new multifaceted and personalised care pathway, compared with usual care, for people with pain at three months after total knee replacement. We report trial participants’ experiences of postoperative pain and the acceptability of the STAR care pathway, which consisted of an assessment clinic at three months, and up to six follow-up telephone calls over 12 months.

Methods

Semi-structured interviews were conducted with 27 people (10 men, 17 women) between February 2018 and January 2020. Participants were sampled purposively from the care pathway intervention group and interviewed after completion of the final postoperative trial questionnaire at approximately 15 months after knee replacement. Interviews were audio-recorded, transcribed, anonymised and analysed using inductive thematic analysis.

Findings

Many participants were unprepared for the severity and impact of postoperative pain, which they described as extreme and constant and that tested their physical and mental endurance. Participants identified ‘low points’ during their recovery, triggered by stiffening, pain or swelling that caused feelings of anxiety, depression, and pain catastrophising. Participants described the STAR assessment clinic as something that seemed “perfectly normal” suggesting it was seamlessly integrated into NHS care. Even in the context of some ongoing pain, the STAR care pathway had provided a source of support and an opportunity to discuss concerns about their ongoing recovery.

Conclusions

People who have knee replacement may be unprepared for the severity and impact of postoperative pain, and the hard work of recovery afterwards. This highlights the challenges of preparing patients for total knee replacement and suggests that clinical attention is needed if exercise and mobilising is painful beyond the three month postoperative period. The STAR care pathway is acceptable to people with pain after total knee replacement.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05423-5.

P170 I think the mental aspect is just awful: experiences of young men living with inflammatory arthritis

Background/Aims

Health-related quality of life (HRQoL) is consistently reported to be reduced in people with inflammatory arthritis (IA), but little is known about the specific experiences of young men living with these conditions. This study seeks to address this knowledge gap and identify key aspects of the patient perspective.

Methods

Online semi-structured interviews with male IA patients age 16-30. Participants were recruited via online platforms and participating NHS Trusts. Data were analysed using reflective thematic analysis.

Results

17 male patients (RA, JIA, PsA, AS); mean age 23 years (SD: 3.87); disease duration 7 years (SD 6.41); medication (100% on DMARDs/ biologic). Five themes are proposed: “it had a massive mental impact on me”: Psychosocial burden. Participants explicitly described the burden of IA on mental health and wellbeing (“From the diagnosis afterwards is when my mental health was really impacted”). Participants highlighted difficulties in discussing these challenges with healthcare professionals, despite a desire to do so. “I’m still quite candid about who I disclose it to”: Selective disclosure. Participants reported using caution in discussing their condition, which may be a protective mechanism for young men giving them a sense of control (“I think just as a bit of a control thing [...] I didn't want people to know everything”).“I view my arthritis as emasculating”: Disrupted and disruptive masculinity. For some, IA interfered with how they wanted to be as a man (“That kind of sums it up, just not being able to fulfil that role of sort of being the man”). Societal expectations seemed to shape their view on how they as young men should manage (“I think you're expected to manage your own feelings and your own everything and go through it [⋯] like, just man up and take it”). “You have to keep going, you have to keep the ball rolling”: Remarkable resilience. Participants expressed resilience in response to setbacks and ongoing challenges. (“I can't just sit back and cry, I need to get on with it and move on”). “It is a roller coaster, you know, you're okay one minute then you're not”: Sense of uncertainty. Participants explained IA brought uncertainty and instability into their lives, adding a layer of difficulty to planning next steps as a young adult (“It makes planning very difficult. I feel like I'm always waiting for something to happen”).

Conclusion

IA can influence young men’s sense of self and may interfere with their ability to navigate emerging adulthood. Some young men report IA having considerable impact on their mental health and wellbeing. Next steps will explore clinician’s perspectives on caring for this patient group to help understand how young men might be better supported

Disclosure

R.J. McNeil-Walsh: None. C.A. Flurey: None. F. Cramp: None. J. Robson: None. C. Eccleston: None. P.M. Galdas: None. L. Cushnie: None.

System-level policies on appropriate opioid use, a multi-stakeholder consensus

BACKGROUND

This consensus statement was developed because there are concerns about the appropriate use of opioids for acute pain management, with opposing views in the literature. Consensus statement on policies for system-level interventions may help inform organisations such as management structures, government agencies and funding bodies.

METHODS

We conducted a multi-stakeholder survey using a modified Delphi methodology focusing on policies, at the system level, rather than at the prescriber or patient level. We aimed to provide consensus statements for current developments and priorities for future developments.

RESULTS

Twenty-five experts from a variety of fields with experience in acute pain management were invited to join a review panel, of whom 23 completed a modified Delphi survey of policies designed to improve the safety and quality of opioids prescribing for acute pain in the secondary care setting. Strong agreement, defined as consistent among> 75% of panellists, was observed for ten statements.

CONCLUSIONS

Using a modified Delphi study, we found agreement among a multidisciplinary panel, including patient representation, on prioritisation of policies for system-level interventions, to improve governance, pain management, patient/consumers care, safety and engagement.

The STAR care pathway for patients with pain at 3 months after total knee replacement: a multicentre, pragmatic, randomised, controlled trial

BACKGROUND

Approximately 20% of people experience chronic pain after total knee replacement, but effective treatments are not available. We aimed to evaluate the clinical effectiveness and cost-effectiveness of a new care pathway for chronic pain after total knee replacement.

METHODS

We did an unmasked, parallel group, pragmatic, superiority, randomised, controlled trial at eight UK National Health Service (NHS) hospitals. People with chronic pain at 3 months after total knee replacement surgery were randomly assigned (2:1) to the Support and Treatment After Replacement (STAR) care pathway plus usual care, or to usual care alone. The STAR intervention aimed to identify underlying causes of chronic pain and enable onward referrals for targeted treatment through a 3-month post-surgery assessment with an extended scope practitioner and telephone follow-up over 12 months. Co-primary outcomes were self-reported pain severity and pain interference in the replaced knee, assessed with the Brief Pain Inventory (BPI) pain severity and interference scales at 12 months (scored 0-10, best to worst) and analysed on an as-randomised basis. Resource use, collected from electronic hospital records and participants, was valued with UK reference costs. Quality-adjusted life-years (QALYs) were calculated from EQ-5D-5L responses. This trial is registered with ISRCTN, ISRCTN92545361.

FINDINGS

Between Sept 6, 2016, and May 31, 2019, 363 participants were randomly assigned to receive the intervention plus usual care (n=242) or to receive usual care alone (n=121). Participants had a median age of 67 years (IQR 61 to 73), 217 (60%) of 363 were female, and 335 (92%) were White. 313 (86%) patients provided follow-up data at 12 months after randomisation (213 assigned to the intervention plus usual care and 100 assigned to usual care alone). At 12 months, the mean between-group difference in the BPI severity score was -0·65 (95% CI -1·17 to -0·13; p=0·014) and the mean between-group difference in the BPI interference score was -0·68 (-1·29 to -0·08; p=0·026), both favouring the intervention. From an NHS and personal social services perspective, the intervention was cost-effective (greater improvement with lower cost), with an incremental net monetary benefit of £1256 (95% CI 164 to 2348) at £20 000 per QALY threshold. One adverse reaction of participant distress was reported in the intervention group.

INTERPRETATION

STAR is a clinically effective and cost-effective intervention to improve pain outcomes over 1 year for people with chronic pain at 3 months after total knee replacement surgery.

FUNDING

National Institute for Health Research.

Systematic reviews do not (yet) represent the 'gold standard' of evidence: A position paper

The low quality of included trials, insufficient rigour in review methodology, ignorance of key pain issues, small size, and over-optimistic judgements about the direction and magnitude of treatment effects all devalue systematic reviews, supposedly the 'gold standard' of evidence. Available evidence indicates that almost all systematic reviews in the published literature contain fatal flaws likely to make their conclusions incorrect and misleading. Only 3 in every 100 systematic reviews are deemed to have adequate methods and be clinically useful. Examples of research waste and questionable ethical standards abound: most trials have little hope of providing useful results, and systematic review of hopeless trials inspires no confidence. We argue that results of most systematic reviews should be dismissed. Forensically critical systematic reviews are essential tools to improve the quality of trials and should be encouraged and protected.

Risk factors associated with poor pain outcomes following primary knee replacement surgery: Analysis of data from the clinical practice research datalink, hospital episode statistics and patient reported outcomes as part of the STAR research programme

Objective

Identify risk factors for poor pain outcomes six months after primary knee replacement surgery.

Methods

Observational cohort study on patients receiving primary knee replacement from the UK Clinical Practice Research Datalink, Hospital Episode Statistics and Patient Reported Outcomes. A wide range of variables routinely collected in primary and secondary care were identified as potential predictors of worsening or only minor improvement in pain, based on the Oxford Knee Score pain subscale. Results are presented as relative risk ratios and adjusted risk differences (ARD) by fitting a generalized linear model with a binomial error structure and log link function.

Results

Information was available for 4,750 patients from 2009 to 2016, with a mean age of 69, of whom 56.1% were female. 10.4% of patients had poor pain outcomes. The strongest effects were seen for pre-operative factors: mild knee pain symptoms at the time of surgery (ARD 18.2% (95% Confidence Interval 13.6, 22.8), smoking 12.0% (95% CI:7.3, 16.6), living in the most deprived areas 5.6% (95% CI:2.3, 9.0) and obesity class II 6.3% (95% CI:3.0, 9.7). Important risk factors with more moderate effects included a history of previous knee arthroscopy surgery 4.6% (95% CI:2.5, 6.6), and use of opioids 3.4% (95% CI:1.4, 5.3) within three months after surgery. Those patients with worsening pain state change had more complications by 3 months (11.8% among those in a worse pain state vs. 2.7% with the same pain state).

Conclusions

We quantified the relative importance of individual risk factors including mild pre-operative pain, smoking, deprivation, obesity and opioid use in terms of the absolute proportions of patients achieving poor pain outcomes. These findings will support development of interventions to reduce the numbers of patients who have poor pain outcomes.

Efficacy and safety of pharmacological, physical, and psychological interventions for the management of chronic pain in children: a WHO systematic review and meta-analysis

ABSTRACT

Chronic pain in childhood is an international public health problem. We conducted a systematic review and meta-analysis to provide a summary of the published evidence of pharmacological, physical, and psychological therapies for children with chronic pain conditions. We searched CENTRAL, MEDLINE, EMBASE, and PsycINFO from inception to April 2020; clinical trial registries; and other sources for randomised controlled trials or comparative observational trials. We extracted critical outcomes of pain intensity, quality of life, physical functioning, role functioning, emotional functioning, sleep, and adverse events. We assessed studies for risk of bias and certainty of the evidence using GRADE. We included 34 pharmacological (4091 participants), 25 physical therapy (1470 participants), and 63 psychological trials (5025 participants). Participants reported a range of chronic pain conditions. Most studies were assessed to have unclear or high risk of bias across multiple domains. Pharmacological, physical, and psychological therapies showed some benefit for reducing pain, posttreatment, but only physical and psychological therapies improved physical functioning. We found no benefit of any treatment modality for health-related quality of life, role functioning, emotional functioning, or sleep. Adverse events were poorly reported, particularly for psychological and physical interventions. The largest evidence base for the management of chronic pain in children supports the use of psychological therapies, followed by pharmacological and physical therapies. However, we rated most outcomes as low or very low certainty, meaning further evidence is likely to change our confidence in the estimates of effects. This protocol was registered on PROSPERO (CRD42020172451).

Implanted spinal neuromodulation interventions for chronic pain in adults

BACKGROUND

Implanted spinal neuromodulation (SNMD) techniques are used in the treatment of refractory chronic pain. They involve the implantation of electrodes around the spinal cord (spinal cord stimulation (SCS)) or dorsal root ganglion (dorsal root ganglion stimulation (DRGS)), and a pulse generator unit under the skin. Electrical stimulation is then used with the aim of reducing pain intensity.

OBJECTIVES

To evaluate the efficacy, effectiveness, adverse events, and cost-effectiveness of implanted spinal neuromodulation interventions for people with chronic pain.

SEARCH METHODS

We searched CENTRAL, MEDLINE Ovid, Embase Ovid, Web of Science (ISI), Health Technology Assessments, ClinicalTrials.gov and World Health Organization International Clinical Trials Registry from inception to September 2021 without language restrictions, searched the reference lists of included studies and contacted experts in the field.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing SNMD interventions with placebo (sham) stimulation, no treatment or usual care; or comparing SNMD interventions + another treatment versus that treatment alone. We included participants ≥ 18 years old with non-cancer and non-ischaemic pain of longer than three months duration. Primary outcomes were pain intensity and adverse events. Secondary outcomes were disability, analgesic medication use, health-related quality of life (HRQoL) and health economic outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened database searches to determine inclusion, extracted data and evaluated risk of bias for prespecified results using the Risk of Bias 2.0 tool. Outcomes were evaluated at short- (≤ one month), medium- four to eight months) and long-term (≥12 months). Where possible we conducted meta-analyses. We used the GRADE system to assess the certainty of evidence.

MAIN RESULTS

We included 15 unique published studies that randomised 908 participants, and 20 unique ongoing studies. All studies evaluated SCS. We found no eligible published studies of DRGS and no studies comparing SCS with no treatment or usual care. We rated all results evaluated as being at high risk of bias overall. For all comparisons and outcomes where we found evidence, we graded the certainty of the evidence as low or very low, downgraded due to limitations of studies, imprecision and in some cases, inconsistency. Active stimulation versus placebo SCS versus placebo (sham) Results were only available at short-term follow-up for this comparison. Pain intensity Six studies (N = 164) demonstrated a small effect in favour of SCS at short-term follow-up (0 to 100 scale, higher scores = worse pain, mean difference (MD) -8.73, 95% confidence interval (CI) -15.67 to -1.78, very low certainty). The point estimate falls below our predetermined threshold for a clinically important effect (≥10 points). No studies reported the proportion of participants experiencing 30% or 50% pain relief for this comparison. Adverse events (AEs) The quality and inconsistency of adverse event reporting in these studies precluded formal analysis. Active stimulation + other intervention versus other intervention alone SCS + other intervention versus other intervention alone (open-label studies) Pain intensity Mean difference Three studies (N = 303) demonstrated a potentially clinically important mean difference in favour of SCS of -37.41 at short term (95% CI -46.39 to -28.42, very low certainty), and medium-term follow-up (5 studies, 635 participants, MD -31.22 95% CI -47.34 to -15.10 low-certainty), and no clear evidence for an effect of SCS at long-term follow-up (1 study, 44 participants, MD -7 (95% CI -24.76 to 10.76, very low-certainty). Proportion of participants reporting ≥50% pain relief We found an effect in favour of SCS at short-term (2 studies, N = 249, RR 15.90, 95% CI 6.70 to 37.74, I² 0% ; risk difference (RD) 0.65 (95% CI 0.57 to 0.74, very low certainty), medium term (5 studies, N = 597, RR 7.08, 95 %CI 3.40 to 14.71, I² = 43%; RD 0.43, 95% CI 0.14 to 0.73, low-certainty evidence), and long term (1 study, N = 87, RR 15.15, 95% CI 2.11 to 108.91 ; RD 0.35, 95% CI 0.2 to 0.49, very low certainty) follow-up. Adverse events (AEs) Device related No studies specifically reported  device-related adverse events at short-term follow-up. At medium-term follow-up, the incidence of lead failure/displacement (3 studies N = 330) ranged from 0.9 to 14% (RD 0.04, 95% CI -0.04 to 0.11, I² 64%, very low certainty). The incidence of infection (4 studies, N = 548) ranged from 3 to 7% (RD 0.04, 95%CI 0.01, 0.07, I² 0%, very low certainty). The incidence of reoperation/reimplantation (4 studies, N =5 48) ranged from 2% to 31% (RD 0.11, 95% CI 0.02 to 0.21, I² 86%, very low certainty). One study (N = 44) reported a 55% incidence of lead failure/displacement (RD 0.55, 95% CI 0.35, 0 to 75, very low certainty), and a 94% incidence of reoperation/reimplantation (RD 0.94, 95% CI 0.80 to 1.07, very low certainty) at five-year follow-up. No studies provided data on infection rates at long-term follow-up. We found reports of some serious adverse events as a result of the intervention. These included autonomic neuropathy, prolonged hospitalisation, prolonged monoparesis, pulmonary oedema, wound infection, device extrusion and one death resulting from subdural haematoma. Other No studies reported the incidence of other adverse events at short-term follow-up. We found no clear evidence of a difference in otherAEs at medium-term (2 studies, N = 278, RD -0.05, 95% CI -0.16 to 0.06, I² 0%) or long term (1 study, N = 100, RD -0.17, 95% CI -0.37 to 0.02) follow-up. Very limited evidence suggested that SCS increases healthcare costs. It was not clear whether SCS was cost-effective.

AUTHORS' CONCLUSIONS

We found very low-certainty evidence that SCS may not provide clinically important benefits on pain intensity compared to placebo stimulation. We found low- to very low-certainty evidence that SNMD interventions may provide clinically important benefits for pain intensity when added to conventional medical management or physical therapy. SCS is associated with complications including infection, electrode lead failure/migration and a need for reoperation/re-implantation. The level of certainty regarding the size of those risks is very low. SNMD may lead to serious adverse events, including death. We found no evidence to support or refute the use of DRGS for chronic pain.

Core outcome set for pediatric chronic pain clinical trials: results from a Delphi poll and consensus meeting

Appropriate outcome measures and high-quality intervention trials are critical to advancing care for children with chronic pain. Our aim was to update a core outcome set for pediatric chronic pain interventions. The first phase involved collecting providers', patients', and parents' perspectives about treatment of pediatric chronic pain to understand clinically meaningful outcomes to be routinely measured. The second phase was to reach consensus of mandatory and optional outcome domains following the OMERACT framework. A modified Delphi study with 2 rounds was conducted including 3 stakeholder groups: children with chronic pain (n = 93), their parents (n = 90), and health care providers who treat youth with chronic pain (n = 52). Quantitative and qualitative data from round 1 of the Delphi study were summarized to identify important outcomes, which were condensed to a list of 10 outcome domains. Round 2 surveys were analyzed to determine the importance of the 10 domains and their relative ranking in each stakeholder group. A virtual consensus conference was held with the steering committee to reach consensus on a set of recommended outcome domains for pediatric chronic pain clinical trials. It was determined, by unanimous vote, that pain severity, pain interference with daily living, overall well-being, and adverse events, including death, would be considered mandatory domains to be assessed in all trials of any type of intervention. Emotional functioning, physical functioning, and sleep were important but optional domains. Last, the research agenda identifies several important emerging areas, including biomarkers. Future work includes selecting appropriate validated measures to assess each outcome domain.

General risks of harm with cannabinoids, cannabis, and cannabis-based medicine possibly relevant to patients receiving these for pain management: an overview of systematic reviews

ABSTRACT

The growing demand for improved pain treatments together with expanding legalization of, and access to, cannabinoids, cannabis, and cannabis-based medicines has intensified the focus on risk-benefit considerations in pain management. Given limited harms data from analgesic clinical trials, we conducted an overview of systematic reviews focused on all harms possibly relevant to patients receiving cannabinoids for pain management. This PROSPERO-registered, PRISMA-compliant systematic overview identified 79 reviews, encompassing over 2200 individual reports about psychiatric and psychosocial harms, cognitive/behavioral effects, motor vehicle accidents, cardiovascular, respiratory, cancer-related, maternal/fetal, and general harms. Reviews, and their included studies, were of variable quality. Available evidence suggests variable associations between cannabis exposure (ranging from monthly to daily use based largely on self-report) and psychosis, motor vehicle accidents, respiratory problems, and other harms. Most evidence comes from settings other than that of pain management (eg, nonmedicinal and experimental) but does signal a need for caution and more robust harms evaluation in future studies. Given partial overlap between patients receiving cannabinoids for pain management and individuals using cannabinoids for other reasons, lessons from the crisis of oversupply and overuse of opioids in some parts of the world emphasize the need to broadly consider harms evidence from real-world settings. The advancement of research on cannabinoid harms will serve to guide optimal approaches to the use of cannabinoids for pain management. In the meantime, this evidence should be carefully examined when making risk-benefit considerations about the use of cannabinoids, cannabis, and cannabis-based medicine for chronic pain.

Cannabinoids, cannabis, and cannabis-based medicines for pain management: an overview of systematic reviews

ABSTRACT

Cannabinoids, cannabis, and cannabis-based medicines (CBM) are increasingly used to manage pain, with limited understanding of their efficacy and safety. We assessed methodological quality, scope, and results of systematic reviews of randomised controlled trials of these treatments. Several search strategies sought self-declared systematic reviews. Methodological quality was assessed using both AMSTAR-2 and techniques important for bias reduction in pain studies. Of the 106 articles read, 57 were self-declared systematic reviews, most published since 2010. They included any type of cannabinoid, cannabis, or CBM, at any dose, however administered, in a broad range of pain conditions. No review examined the effects of a particular cannabinoid, at a particular dose, using a particular route of administration, for a particular pain condition, reporting a particular analgesic outcome. Confidence in the results in the systematic reviews using AMSTAR-2 definitions was critically low (41), low (8), moderate (6), or high (2). Few used criteria important for bias reduction in pain. Cochrane reviews typically provided higher confidence; all industry-conflicted reviews provided critically low confidence. Meta-analyses typically pooled widely disparate studies, and, where assessable, were subject to potential publication bias. Systematic reviews with positive or negative recommendation for use of cannabinoids, cannabis, or CBM in pain typically rated critically low or low (24/25 [96%] positive; 10/12 [83%] negative). Current reviews are mostly lacking in quality and cannot provide a basis for decision-making. A new high-quality systematic review of randomised controlled trials is needed to critically assess the clinical evidence for cannabinoids, cannabis, or CBM in pain.

Cannabinoids, cannabis, and cannabis-based medicine for pain management: a systematic review of randomised controlled trials

ABSTRACT

Cannabinoids, cannabis, and cannabis-based medicines (CBMs) are increasingly used to manage pain, with limited understanding of their efficacy and safety. We summarised efficacy and adverse events (AEs) of these types of drugs for treating pain using randomised controlled trials: in people of any age, with any type of pain, and for any treatment duration. Primary outcomes were 30% and 50% reduction in pain intensity, and AEs. We assessed risk of bias of included studies, and the overall quality of evidence using GRADE. Studies of <7 and >7 days treatment duration were analysed separately. We included 36 studies (7217 participants) delivering cannabinoids (8 studies), cannabis (6 studies), and CBM (22 studies); all had high and/or uncertain risk of bias. Evidence of benefit was found for cannabis <7 days (risk difference 0.33, 95% confidence interval 0.20-0.46; 2 trials, 231 patients, very low-quality evidence) and nabiximols >7 days (risk difference 0.06, 95% confidence interval 0.01-0.12; 6 trials, 1484 patients, very low-quality evidence). No other beneficial effects were found for other types of cannabinoids, cannabis, or CBM in our primary analyses; 81% of subgroup analyses were negative. Cannabis, nabiximols, and delta-9-tetrahydrocannabinol had more AEs than control. Studies in this field have unclear or high risk of bias, and outcomes had GRADE rating of low- or very low-quality evidence. We have little confidence in the estimates of effect. The evidence neither supports nor refutes claims of efficacy and safety for cannabinoids, cannabis, or CBM in the management of pain.

International Association for the Study of Pain Presidential Task Force on Cannabis and Cannabinoid Analgesia: research agenda on the use of cannabinoids, cannabis, and cannabis-based medicines for pain management

ABSTRACT

The President of the International Association for the Study of Pain established a task force on cannabis and cannabinoid analgesia to systematically examine the evidence on (1) analgesic pharmacology of cannabinoids and preclinical evidence on their efficacy in animal models of injury-related or pathological persistent pain; (2) the clinical efficacy of cannabis, cannabinoids, and cannabis-based medicines for pain; (3) harms related to long-term use of cannabinoids; as well as (4) societal issues and policy implications related to the use of these compounds for pain management. Here, we summarize key knowledge gaps identified in the task force outputs and propose a research agenda for generating high-quality evidence on the topic. The systematic assessment of preclinical and clinical literature identified gaps in rigor of study design and reporting across the translational spectrum. We provide recommendations to improve the quality, rigor, transparency, and reproducibility of preclinical and clinical research on cannabis and cannabinoids for pain, as well as for the conduct of systematic reviews on the topic. Gaps related to comprehensive understanding of the endocannabinoid system and cannabinoid pharmacology, including pharmacokinetics and drug formulation aspects, are discussed. We outline key areas where high-quality clinical trials with cannabinoids are needed. Remaining important questions about long-term and short-term safety of cannabis and cannabinoids are emphasized. Finally, regulatory, societal, and policy challenges associated with medicinal and nonmedicinal use of cannabis are highlighted, with recommendations for improving patient safety and reducing societal harms in the context of pain management.

Attentional Biases Towards Body Expressions of Pain in Men and Women

This study investigated whether there are gender differences in attention to bodily expressions of pain and core emotions. Three experiments are reported using the attentional dot probe task. Images of men and women displaying bodily expressions, including pain, were presented. The task was used to determine whether participants' attention was drawn towards or away from target expressions. Inconsistent evidence was found for an attentional bias towards body expressions, including pain. While biases were affected by gender, patterns varied across the Experiments. Experiment 1, which had a presentation duration of 500 ms, found a relative bias towards the location of male body expressions compared to female expressions. Experiments 2 and 3 varied stimulus exposure times by including both shorter and longer duration conditions (e.g., 100 vs. 500 vs. 1250 ms). In these experiments, a bias towards pain was confirmed. Gender differences were also found, especially in the longer presentation conditions. Expressive body postures captured the attention of women for longer compared to men. These results are discussed in light of their implications for why there are gender differences in attention to pain, and what impact this has on pain behaviour. PERSPECTIVE: We show that men and women might differ in how they direct their attention towards bodily expressions, including pain. These results have relevance to understanding how carers might attend to the pain of others, as well as highlighting the wider role that social-contextual factors have in pain.

Psychological aspects of pain prevention

How to prevent the onset, maintenance, or exacerbation of pain is a major focus of clinical pain science. Pain prevention can be distinctly organised into primary, secondary, and tertiary prevention. Primary prevention describes avoiding hurt or pain, secondary prevention describes reducing pain when pain is unavoidable, and tertiary prevention describes preventing or reducing ongoing negative consequences such as high functional disability or distress due to chronic pain. Each poses separate challenges where unique psychological factors will play a role. In this short review article, we highlight psychological factors important to primary, secondary, and tertiary prevention and provide direction for the field. We present 2 case studies on secondary prevention in children and adolescents and tertiary prevention in adults with chronic pain. Finally, we provide research directions for progression in this field, highlighting the importance of clear theoretical direction, the identification of risk factors for those most likely to develop pain, and the importance of treatment.

Sociodevelopmental Challenges Faced by Young People with Chronic Pain: A Scoping Review

OBJECTIVE

Map the current literature investigating autonomy development, identity development, and peer relationships in young people aged 10-24 years with chronic pain.

METHODS

A scoping review method was used to systematically search four databases (APA PsycNET, PubMed, Web of Science, and Cinahl) for peer-reviewed articles. Search results were screened against inclusion and exclusion criteria to ensure they met the objective. Eligible papers were assessed for quality, their data relating to the objective were extracted, and results are synthesized.

RESULTS

Searches returned 3,815 papers after the removal of duplicates, with 42 papers included in the full review. The majority of papers investigated peer relationships (86%). Fewer papers investigated autonomy (43%) and identity (21%) development. Included papers were mostly quantitative (64%), with fewer qualitative (34%) and mixed-methods papers (2%). Overall, we found bidirectional relationships between chronic pain in young people, their social development, and a range of functional outcomes. However, the mechanisms underlying these relationships remain relatively unexplored.

CONCLUSIONS

Review results are mapped onto the model proposed by Palermo et al. (2014). Guided by this model, clinical treatment for young people with chronic pain should consider social development. The model also sets out a future research agenda focused on exploring: (a) identity development, (b) the mechanisms underlying the relationships between social-developmental domains, pain, and outcomes, (c) a variety of participants and populations, and (d) a variety of methods, including longitudinal study designs.

"It's not my knee" - understanding ongoing pain and discomfort after total knee replacement through (re)embodiment

Objective

Up to 20% of people who undergo total knee replacement surgery have ongoing pain and discomfort. The aim of this study was to understand what role the concepts of embodiment (of both having a body and experiencing the world through one's body) and incorporation (integrating something into one's body) might have in understanding experiences of pain and discomfort after total knee replacement.

Methods

We conducted semistructured interviews with 34 people who had received total knee replacement at either of 2 National Health Service hospitals in the UK, and who had chronic postsurgical pain (n = 34, ages 55–93 years). Data were audiorecorded, transcribed, and analyzed thematically.

Results

Two main themes were identified: 1) when describing chronic postsurgical pain, some participants also described sensations of discomfort, including heaviness, numbness, pressure, and tightness associated with the prosthesis; 2) participants reported a lack of felt connection with and agency over their replaced knee, often describing it as alien or other, and lacked confidence in the knee.

Conclusion

Participants’ experiences indicate that some people do not achieve full incorporation of the prosthesis. Our study emphasizes the importance of physicians treating patients as whole people and moving beyond clinical and procedural ideas of success. Our findings suggest that to optimize postoperative outcomes, rehabilitation must focus not only on strengthening the joint and promoting full recovery to tasks but on modifying a person's relationship to the new joint and managing sensations of otherness to achieve full incorporation of the joint or re‐embodiment.

Screening to identify postoperative pain and cross-sectional associations between factors identified in this process with pain and function, three months after total knee replacement

Objective

To describe the screening and recruitment process of a randomized trial and evaluate associations with knee pain and function 3 months after total knee replacement (TKR).

Methods

In order to screen for a multicenter trial, a total of 5,036 patients were sent the Oxford Knee Score (OKS) questionnaire 10 weeks post‐TKR. Patients who reported pain in their replaced knee (score of ≤14 on the OKS pain component) completed a second OKS questionnaire 12 weeks post‐TKR. Those patients who were still experiencing pain 12 weeks post‐TKR completed a detailed questionnaire 13 weeks post‐TKR. These data were used to characterize pain in a cross‐sectional analysis. Multivariable regression was performed in order to identify factors associated with pain and function at 13 weeks post‐TKR.

Results

We received OKS questionnaires from 3,058 of 5,063 TKR patients (60%), and 907 of the 3,058 (30%) reported pain in their replaced knee 10 weeks post‐TKR. By 12 weeks, 179 of 553 patients (32%) reported improved pain (score of >14 on the OKS pain component). At 13 weeks, 192 of 363 patients (53%) who completed a detailed questionnaire reported neuropathic pain, 94 of 362 (26%) reported depression symptoms, and 95 of 363 (26%) anxiety symptoms. More severe pain at 13 weeks postoperatively was associated with poorer general health, poorer physical health, more pain worry, and lower satisfaction with surgery outcome. More severe functional limitation was associated with higher levels of depression, more pain worry, lower satisfaction with surgery outcome, and higher pain acceptance.

Conclusion

Screening after TKR identified individuals with pain. We identified several potential targets (physical and mental health outcomes, acceptance of pain, and quality of life) for tailored intervention to improve outcomes for patients. Future trials of multidisciplinary interventions warranted.

Interpretation of chronic pain clinical trial outcomes: IMMPACT recommended considerations

Interpreting randomized clinical trials (RCTs) is crucial to making decisions regarding the use of analgesic treatments in clinical practice. In this article, we report on an Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) consensus meeting organized by the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks, the purpose of which was to recommend approaches that facilitate interpretation of analgesic RCTs. We review issues to consider when drawing conclusions from RCTs, as well as common methods for reporting RCT results and the limitations of each method. These issues include the type of trial, study design, statistical analysis methods, magnitude of the estimated beneficial and harmful effects and associated precision, availability of alternative treatments and their benefit-risk profile, clinical importance of the change from baseline both within and between groups, presentation of the outcome data, and the limitations of the approaches used.

Psychological therapies for the management of chronic pain (excluding headache) in adults

BACKGROUND

Chronic non-cancer pain, a disabling and distressing condition, is common in adults. It is a global public health problem and economic burden on health and social care systems and on people with chronic pain. Psychological treatments aim to reduce pain, disability and distress. This review updates and extends its previous version, published in 2012.

OBJECTIVES

To determine the clinical efficacy and safety of psychological interventions for chronic pain in adults (age > 18 years) compared with active controls, or waiting list/treatment as usual (TAU).

SEARCH METHODS

We identified randomised controlled trials (RCTs) of psychological therapies by searching CENTRAL, MEDLINE, Embase and PsycINFO to 16 April 2020. We also examined reference lists and trial registries, and searched for studies citing retrieved trials.

SELECTION CRITERIA

RCTs of psychological treatments compared with active control or TAU of face-to-face therapies for adults with chronic pain. We excluded studies of headache or malignant disease, and those with fewer than 20 participants in any arm at treatment end.

DATA COLLECTION AND ANALYSIS

Two or more authors rated risk of bias, extracted data, and judged quality of evidence (GRADE). We compared cognitive behavioural therapy (CBT), behavioural therapy (BT), and acceptance and commitment therapy (ACT) with active control or TAU at treatment end, and at six month to 12 month follow-up. We did not analyse the few trials of other psychological treatments. We assessed treatment effectiveness for pain intensity, disability, and distress. We extracted data on adverse events (AEs) associated with treatment.

MAIN RESULTS

We added 41 studies (6255 participants) to 34 of the previous review's 42 studies, and now have 75 studies in total (9401 participants at treatment end). Most participants had fibromyalgia, chronic low back pain, rheumatoid arthritis, or mixed chronic pain. Most risk of bias domains were at high or unclear risk of bias, with selective reporting and treatment expectations mostly at unclear risk of bias. AEs were inadequately recorded and/or reported across studies. CBT The largest evidence base was for CBT (59 studies). CBT versus active control showed very small benefit at treatment end for pain (standardised mean difference (SMD) -0.09, 95% confidence interval (CI) -0.17 to -0.01; 3235 participants; 23 studies; moderate-quality evidence), disability (SMD -0.12, 95% CI -0.20 to -0.04; 2543 participants; 19 studies; moderate-quality evidence), and distress (SMD -0.09, 95% CI -0.18 to -0.00; 3297 participants; 24 studies; moderate-quality evidence). We found small benefits for CBT over TAU at treatment end for pain (SMD -0.22, 95% CI -0.33 to -0.10; 2572 participants; 29 studies; moderate-quality evidence), disability (SMD -0.32, 95% CI -0.45 to -0.19; 2524 participants; 28 studies; low-quality evidence), and distress (SMD -0.34, 95% CI -0.44 to -0.24; 2559 participants; 27 studies; moderate-quality evidence). Effects were largely maintained at follow-up for CBT versus TAU, but not for CBT versus active control. Evidence quality for CBT outcomes ranged from moderate to low. We rated evidence for AEs as very low quality for both comparisons. BT We analysed eight studies (647 participants). We found no evidence of difference between BT and active control at treatment end (pain SMD -0.67, 95% CI -2.54 to 1.20, very low-quality evidence; disability SMD -0.65, 95% CI -1.85 to 0.54, very low-quality evidence; or distress SMD -0.73, 95% CI -1.47 to 0.01, very low-quality evidence). At follow-up, effects were similar. We found no evidence of difference between BT and TAU (pain SMD -0.08, 95% CI -0.33 to 0.17, low-quality evidence; disability SMD -0.02, 95% CI -0.24 to 0.19, moderate-quality evidence; distress SMD 0.22, 95% CI -0.10 to 0.54, low-quality evidence) at treatment end. At follow-up, we found one to three studies with no evidence of difference between BT and TAU. We rated evidence for all BT versus active control outcomes as very low quality; for BT versus TAU. Evidence quality ranged from moderate to very low. We rated evidence for AEs as very low quality for BT versus active control. No studies of BT versus TAU reported AEs. ACT We analysed five studies (443 participants). There was no evidence of difference between ACT and active control for pain (SMD -0.54, 95% CI -1.20 to 0.11, very low-quality evidence), disability (SMD -1.51, 95% CI -3.05 to 0.03, very low-quality evidence) or distress (SMD -0.61, 95% CI -1.30 to 0.07, very low-quality evidence) at treatment end. At follow-up, there was no evidence of effect for pain or distress (both very low-quality evidence), but two studies showed a large benefit for reducing disability (SMD -2.56, 95% CI -4.22 to -0.89, very low-quality evidence). Two studies compared ACT to TAU at treatment end. Results should be interpreted with caution. We found large benefits of ACT for pain (SMD -0.83, 95% CI -1.57 to -0.09, very low-quality evidence), but none for disability (SMD -1.39, 95% CI -3.20 to 0.41, very low-quality evidence), or distress (SMD -1.16, 95% CI -2.51 to 0.20, very low-quality evidence). Lack of data precluded analysis at follow-up. We rated evidence quality for AEs to be very low. We encourage caution when interpreting very low-quality evidence because the estimates are uncertain and could be easily overturned.

AUTHORS' CONCLUSIONS

We found sufficient evidence across a large evidence base (59 studies, over 5000 participants) that CBT has small or very small beneficial effects for reducing pain, disability, and distress in chronic pain, but we found insufficient evidence to assess AEs. Quality of evidence for CBT was mostly moderate, except for disability, which we rated as low quality. Further trials may provide more precise estimates of treatment effects, but to inform improvements, research should explore sources of variation in treatment effects. Evidence from trials of BT and ACT was of moderate to very low quality, so we are very uncertain about benefits or lack of benefits of these treatments for adults with chronic pain; other treatments were not analysed. These conclusions are similar to our 2012 review, apart from the separate analysis of ACT.

The Time Course of Facial Expression Recognition Using Spatial Frequency Information: Comparing Pain and Core Emotions

We are able to recognize others' experience of pain from their facial expressions. However, little is known about what makes the recognition of pain possible and whether it is similar or different from core emotions. This study investigated the mechanisms underpinning the recognition of pain expressions, in terms of spatial frequency (SF) information analysis, and compared pain with 2 core emotions (ie, fear and happiness). Two experiments using a backward masking paradigm were conducted to examine the time course of low- and high-SF information processing, by manipulating the presentation duration of face stimuli and target-mask onset asynchrony. Overall, we found a temporal advantage of low-SF over high-SF information for expression recognition, including pain. This asynchrony between low- and high-SF happened at a very early stage of information extraction, which indicates that the decoding of low-SF expression information is not only faster but possibly occurs before the processing of high-SF information. Interestingly, the recognition of pain was also found to be slower and more difficult than core emotions. It is suggested that more complex decoding process may be involved in the successful recognition of pain from facial expressions, possibly due to the multidimensional nature of pain experiences. PERSPECTIVE: Two studies explore the perceptual and temporal properties of the decoding of pain facial expressions. At very early stages of attention, the recognition of pain was found to be more difficult than fear and happiness. It suggests that pain is a complex expression, and requires additional time to detect and process.

Gender differences in attention to pain body postures in a social context: a novel use of the bodies in the crowd task

Pain signals the presence of potential harm, captures attention, and can inhibit performance on concurrent tasks. What is less well known, however, is whether such attentional capture also occurs in a wider social context, such as when observing people in pain. To explore this possibility, we adopted a novel social-cue detection methodology: the bodies-in-the-crowd task. Two experiments are reported that consider whether nonverbal cues of pain, happiness, and anger as expressed through body postures would capture and hold attention. Both experiments recruited 40 (20 male and 20 female) pain-free individuals. Overall, results show that pain postures do not capture attention any more than happiness or anger postures, but disengagement from pain postures was significantly slower across both studies. Gender differences were also found, and were more likely to be found when crowds comprised both men and women. Male pain postures were more likely to capture attention. However, female observers had faster target detection speed, and were quicker to disengage from distractors. They also showed slower disengagement from female expressions overall. Male observers showed no variation based on target or distractor gender. Implications and potential directions for future research are discussed.