Treatment effect modifiers for return-to-work in patients with musculoskeletal disorders.

Investigating how individual characteristics modify treatment effects can improve understanding, interpretation, and translation of trial findings. The purpose of this secondary analysis was to identify treatment effect modifiers of the MI-NAV trial, a three arm, parallel randomized controlled trial which compared motivational interviewing and stratified vocational advice intervention in addition to usual case management, to usual case management alone. This study included (n=514) participants with musculoskeletal disorders on sick leave for at least 50% of their contracted work hours for at least 7 consecutive weeks with the Norwegian Labour and Welfare Administration. Sickness absence days was the primary outcome, measured from baseline assessment date until the six-month follow-up. Potential treatment effect modifiers, identified a priori and informed by expert consultation and literature, were evaluated using linear regression models and statistical interaction tests. For motivational interviewing versus usual case management, age (mean difference -0.7, 95% confidence interval -1.5 to 0.2; P=0.13) and self-perceived health status (mean difference -0.3, 95% confidence interval -0.7 to 0.1; P=0.19) were identified as potential effect modifiers (p ≤ 0.2). For stratified vocational advice intervention versus usual case management, analgesic medication use (MD -26.2, 95% CI -45.7 to -6.7; P=0.009) was identified as a treatment effect modifier (p ≤ 0.05). These findings may assist in more targeted treatment adaptation and translation as well as the planning of future clinical trials. PERSPECTIVE: This secondary analysis of the MI-NAV trial found that analgesic medication use, age and self-perceived health may modify the effect of two vocational interventions on reducing sickness absence in people with musculoskeletal disorders.

Emotion regulation skills-focused interventions for chronic pain: A systematic review and meta-analysis.

OBJECTIVES: To investigate the effect of emotion regulation skills-focused (ERSF) interventions to reduce pain intensity and improve psychological outcomes for people with chronic pain and to narratively report on safety and intervention compliance. METHODS: Six databases and four registries were searched for randomized controlled trials (RCTs) up to 29 April 2022. Risk of bias was evaluated using the Cochrane RoB 2.0 tool, and certainty of evidence was assessed according to the Grading, Assessment, Development and Evaluation (GRADE). Meta-analyses for eight studies (902 participants) assessed pain intensity (primary outcome), emotion regulation, affect, symptoms of depression and anxiety, and pain interference (secondary outcomes), at two time points when available, post-intervention (closest to intervention end) and follow-up (the first measurement after the post-intervention assessment). RESULTS: Compared to TAU, pain intensity improved post-intervention (weighted mean difference [WMD] = -10.86; 95% confidence interval [CI] [-17.55, -2.56]) and at follow-up (WMD = -11.38; 95% CI [-13.55, -9.21]). Emotion regulation improved post-intervention (standard mean difference [SMD] = 0.57; 95% CI [0.14, 1.01]), and depressive symptoms improved at follow-up (SMD = -0.45; 95% CI [-0.66, -0.24]). Compared to active comparators, anxiety symptoms improved favouring the comparator post-intervention (SMD = 0.10; 95% CI [0.03, 0.18]), and compared to CBT, pain interference improved post-intervention (SMD = -0.37; 95% CI [-0.69, -0.04]). Certainty of evidence ranged from very low to moderate. SIGNIFICANCE: The findings provide evidence that ERSF interventions reduce pain intensity for people with chronic pain compared to usual treatment. These interventions are at least as beneficial to reduce pain intensity as the current gold standard psychological intervention, CBT. However, the limited number of studies and certainty of evidence mean further high-quality RCTs are warranted. Additionally, further research is needed to identify whether ERSF interventions may be more beneficial for specific chronic pain conditions.

The smallest worthwhile effect on pain intensity of exercise therapy for people with chronic low back pain: a discrete choice experiment study.

OBJECTIVE: To identify the smallest worthwhile effect (SWE) of exercise therapy for people with non-specific chronic low back pain (CLBP). DESIGN: Discrete choice experiment. METHODS: The SWE was estimated as the lowest reduction in pain that participants would consider exercising worthwhile, compared to not exercising i.e., effects due to natural history and other components (e.g., regression to the mean). We recruited English-speaking adults in Australia with non-specific CLBP to our online survey via email obtained from a registry of previous participants and advertisements on social media. We used discrete choice experiment to estimate the SWE of exercise compared to no exercise for pain intensity. We analysed the discrete choice experiment using a mixed logit model, and mitigated hypothetical bias through certainty calibration, with sensitivity analyses performed with different certainty calibration thresholds. RESULTS: Two-hundred and thirteen participants completed the survey. The mean age (±SD) was 50.7±16.5, median (IQR) pain duration 10 years (5-20), and mean pain intensity (±SD) was 5.8±2.3 on a 0-10 numerical rating scale. For people with CLBP the SWE of exercise was a between-group reduction in pain of 20%, compared to no exercise. In the sensitivity analyses, the SWE varied with different levels of certainty calibration; from 0% without certainty calibration to 60% with more extreme certainty calibration. CONCLUSION: This patient-informed threshold of clinical importance could guide the interpretation of findings from randomised trials and meta-analyses of exercise therapy compared to no exercise.

Complex regional pain syndrome: advances in epidemiology, pathophysiology, diagnosis, and treatment.

Complex regional pain syndrome (CRPS) is a rare pain disorder that usually occurs in a limb after trauma. The features of this disorder include severe pain and sensory, autonomic, motor, and trophic abnormalities. Research from the past decade has offered new insights into CRPS epidemiology, pathophysiology, diagnosis, and treatment. Early identification of individuals at high risk of CRPS is improving, with several risk factors established and some others identified in prospective studies during the past 5 years. Better understanding of the pathophysiological mechanisms of CRPS has led to its classification as a chronic primary pain disorder, and subtypes of CRPS have been updated. Procedures for diagnosis have also been clarified. Although effective treatment of CRPS remains a challenge, evidence-based integrated management approaches provide new opportunities to improve patient care. Further advances in diagnosis and treatment of CRPS will require coordinated, international multicentre initiatives.

Barriers and enablers to exercise adherence in people with nonspecific chronic low back pain: a systematic review of qualitative evidence.

ABSTRACT: Exercise is a first-line treatment for chronic low back pain (CLBP), reducing pain and disability in the short term. However, exercise benefits decrease over time, with a lack of long-term exercise adherence a potential reason for this. This study aimed to synthesize the perceptions and beliefs of individuals with CLBP and identify their barriers and enablers to exercise adherence. We searched CENTRAL, Embase, CINAHL, SPORTDiscus, PubMed, PsycINFO, and Scopus databases from inception to February 28, 2023, for qualitative studies that explored the factors influencing exercise adherence for people with CLBP. A hybrid approach combining thematic synthesis with the Theoretical Domains Framework was used to analyze data. We assessed methodological quality using the Critical Appraisal Skills Programme checklist and the level of confidence of the themes generated using the Confidence in the Evidence from Reviews of Qualitative Studies. Twenty-three papers (n = 21 studies) were included (n = 677 participants). Four main themes affected exercise adherence: (1) exercise, pain, and the body, (2) psychological factors, (3) social factors, and (4) external factors. These themes contained 16 subthemes that were predominantly both barriers and enablers to exercise adherence. The individual's experiences of barriers and enablers were most appropriately represented across a spectrum, where influencing factors could be a barrier or enabler to exercise adherence, and these could be specific to pre-exercise, during-exercise, and post-exercise situations. These findings may be used to improve exercise adherence and ultimately treatment outcomes in people with CLBP.

It's OK to move! Effect of a brief video on community confidence in activity despite back pain: A randomised trial.

OBJECTIVE: To estimate the difference in confidence to become active despite low back pain in people who were exposed to one of two video interventions delivered on social media, compared to no intervention. DESIGN: A proof of concept three group randomised controlled trial, in a 1:1:1 ratio. METHODS: Participants aged 18 years and over, with and without low back pain, were recruited via the social media channel Facebook, to view either a humorous video, a neutral video or to no intervention. The videos were delivered online, explained evidence-based management for low back pain, and were designed to "go viral". The primary outcome was confidence in becoming active despite pain, measured using the Pain Self Efficacy Questionnaire(Item 10) [range from 0 (not at all confident) to 6 (completely confident)] immediately after watching the video. We aimed to capture the real-time impact and immediate reactions that contributed to the content's reach. RESULTS: Among 1933 randomized participants (mean [SD] age 58.9 [14.0] years, 1285 [75%] women) 1232 [70%] had low back pain and 88.8% completed the primary outcome. 1264 participants were randomised to receive a video intervention, and 633 participants did not receive a video. On a 6-point scale, individuals exposed to either video (n=1088) showed a mean confidence level 0.3 points higher (95% CI 0.1 to 0.6) compared with no video (n=630). CONCLUSION: Participants who viewed a brief video intervention reported a very small difference in confidence to become active despite low back pain, compared with no intervention. The difference may lack clinical relevance.

Generating a list of potentially important contextual factors covering randomized trials, cohorts, and measurement property studies: An OMERACT initiative.

OBJECTIVES: To generate candidates for contextual factors (CFs) for each CF type (i.e., Effect Modifying Contextual Factors (EM-CFs), Outcome Influencing Contextual Factors (OI-CFs), and Measurement Affecting Contextual Factors (MA-CFs)) considered important within rheumatology. METHODS: We surveyed OMERACT working groups and conducted a Special Interest Group (SIG) session at the OMERACT 2023 meeting, where the results were reviewed, and additional CFs suggested. RESULTS: The working groups suggested 44, 49, and 21 generic EM-CFs, OI-CFs, and MA-CFs, respectively. SIG participants added 49, 44, and 55 factors, respectively. CONCLUSION: Candidate CFs were identified, next step is a consensus-based set of endorsed (important) CFs.

Are Exercise Interventions in Clinical Trials for Chronic Low Back Pain Dosed Appropriately to Meet the World Health Organization's Physical Activity Guidelines?

OBJECTIVE: This study aimed to estimate the proportion of exercise interventions tested in clinical trials of people with chronic low back pain (CLBP) that meet the World Health Organization's (WHO) physical activity guidelines. METHODS: A secondary analysis of the 2021 Cochrane review of exercise therapy for CLBP was performed. Data from each study were extracted by 1 reviewer and were checked by a second reviewer. Data extracted related to the frequency, duration and intensity of each exercise intervention, and the proportion of exercise interventions that met the WHO's physical activity guidelines (aerobic, muscle strengthening, or both) were determined. RESULTS: The 249 included trials comprised 426 exercise interventions. Few interventions reported an exercise type and dose consistent with the WHO guidelines (aerobic: 1.6%, muscle strengthening: 5.6%, both: 1.6%). Poor reporting of exercise intensity limited our ability to determine whether interventions met the guidelines. CONCLUSION: Few interventions tested in clinical trials for people with CLBP prescribe an exercise type and dose consistent with the WHO guidelines. Therefore, they do not appear sufficiently dosed to achieve broader health outcomes. Future trials should investigate the effect of WHO guideline-recommended exercise interventions on patient-reported outcomes (pain and disability) as well as health-related outcomes in people with CLBP. IMPACT: This exploratory analysis showed the lack of exercise interventions in the CLBP literature that meet the WHO's physical activity guidelines. With people in chronic pain groups, such as people with CLBP, being at higher risk for noncommunicable disease, it appears this is a key consideration for exercise practitioners when designing interventions for people with CLBP.

Barriers and Enablers to Using Intervention Reporting Guidelines in Sports and Exercise Medicine Trials: A Mixed-Methods Study.

OBJECTIVE: To identify barriers and facilitators for using intervention reporting guidelines (CERT and TIDieR) from authors of randomized controlled trials in sports and exercise medicine journals. DESIGN: Mixed-methods cross-sectional online survey. METHODS: We recruited authors of randomized controlled trials published from June 2, 2018, to June 2, 2022, in the 10 leading sports and exercise medicine journals. We invited authors of eligible trials to complete an online survey that included multiple-choice and Likert-scale questions, as well as open-ended free-text questions on the barriers and facilitators to using intervention reporting guidelines. We used descriptive analysis to summarize the quantitative data and a hybrid deductive-inductive thematic analysis to identify barriers and facilitators from the qualitative data. We conducted a subgroup analysis to explore differences in barriers and facilitators between early-mid career researchers and senior researchers. RESULTS: Eighty-four participants from 21 countries completed the survey (44 early-mid-career researchers, 40 senior researchers). We identified 8 themes relating to using intervention reporting guidelines. Themes classified as barriers related to publication constraints (word count limits), low awareness of intervention reporting guidelines, unclear benefits of the guidelines, and the increased burden imposed upon the researcher. Themes classified as facilitators related to journal requirements for guidelines use, the desire to accurately describe interventions, recommendations from other researchers, and reporting guideline use indicating "quality" of work. CONCLUSION: Barriers to using intervention reporting guidelines are largely modifiable and could be addressed by journals mandating their use, and educational initiatives. J Orthop Sports Phys Ther 2024;54(2):1-11. Epub 16 November 2023. doi:10.2519/jospt.2023.12110.

Development of recommendations for a minimum dataset for Identifying Social factors that Stratify Health Opportunities and Outcomes (ISSHOOs) in pain research.

There is increasing recognition of the need for researchers to collect and report data that can illuminate health inequities. In pain research, routinely collecting equity-relevant data has the potential to inform about the generalisability of findings; whether the intervention has differential effects across strata of society; or it could be used to guide population targeting for clinical studies. Developing clarity and consensus on what data should be collected and how to collect it is required to prompt researchers to further consider equity issues in the planning, conduct, interpretation, and reporting of research. The overarching aim of the 'Identifying Social Factors that Stratify Health Opportunities and Outcomes' (ISSHOOs) in pain research project is to provide researchers in the pain field with recommendations to guide the routine collection of equity-relevant data. The design of this project is consistent with the methods outlined in the 'Guidance for Developers of Health Research Reporting Guidelines' and involves 4 stages: (i) Scoping review; (ii) Delphi Study; (iii) Consensus Meeting; and (iv) Focus Groups. This stakeholder-engaged project will produce a minimum dataset that has global, expert consensus. Results will be disseminated along with explanation and elaboration as a crucial step towards facilitating future action to address avoidable disparities in pain outcomes.

Variation observed in consensus judgments between pairs of reviewers when assessing the risk of bias due to missing evidence in a sample of published meta-analyses of nutrition research.

OBJECTIVES: To evaluate the risk of bias due to missing evidence in a sample of published meta-analyses of nutrition research using the Risk Of Bias due to Missing Evidence (ROB-ME) tool and determine inter-rater agreement in assessments. STUDY DESIGN AND SETTING: We assembled a random sample of 42 meta-analyses of nutrition research. Eight assessors were randomly assigned to one of four pairs. Each pair assessed 21 randomly assigned meta-analyses, and each meta-analysis was assessed by two pairs. We calculated raw percentage agreement and chance corrected agreement using Gwet's Agreement Coefficient (AC) in consensus judgments between pairs. RESULTS: Across the eight signaling questions in the ROB-ME tool, raw percentage agreement ranged from 52% to 100%, and Gwet's AC ranged from 0.39 to 0.76. For the risk-of-bias judgment, the raw percentage agreement was 76% (95% confidence interval 60% to 92%) and Gwet's AC was 0.47 (95% confidence interval 0.14 to 0.80). In seven (17%) meta-analyses, either one or both pairs judged the risk of bias due to missing evidence as "low risk". CONCLUSION: Our findings indicated substantial variation in assessments in consensus judgments between pairs for the signaling questions and overall risk-of-bias judgments. More tutorials and training are needed to help researchers apply the ROB-ME tool more consistently.

Using PROGRESS-plus to identify current approaches to the collection and reporting of equity-relevant data: a scoping review.

OBJECTIVES: Our objectives were to identify what and how data relating to the social determinants of health are collected and reported in equity-relevant studies and map these data to the PROGRESS-Plus framework. STUDY DESIGN AND SETTING: We performed a scoping review. We ran two systematic searches of MEDLINE and Embase for equity-relevant studies published during 2021. We included studies in any language without limitations to participant characteristics. Included studies were required to have collected and reported at least two participant variables relevant to evaluating individual-level social determinants of health. We applied the PROGRESS-Plus framework to identify and organize these data. RESULTS: We extracted data from 200 equity-relevant studies, providing 962 items defined by PROGRESS-Plus. A median of 4 (interquartile range = 2) PROGRESS-Plus items were reported in the included studies. 92% of studies reported age; 78% reported sex/gender; 65% reported educational attainment; 49% reported socioeconomic status; 45% reported race; 44% reported social capital; 33% reported occupation; 14% reported place and 9% reported religion. CONCLUSION: Our synthesis demonstrated that researchers currently collect a limited range of equity-relevant data, but usefully provides a range of examples spanning PROGRESS-Plus to inform the development of improved, standardized practices.

Reporting of Observational Studies Explicitly Aiming to Emulate Randomized Trials: A Systematic Review.

Importance: Observational (nonexperimental) studies that aim to emulate a randomized trial (ie, the target trial) are increasingly informing medical and policy decision-making, but it is unclear how these studies are reported in the literature. Consistent reporting is essential for quality appraisal, evidence synthesis, and translation of evidence to policy and practice. Objective: To assess the reporting of observational studies that explicitly aimed to emulate a target trial. Evidence Review: We searched Medline, Embase, PsycINFO, and Web of Science for observational studies published between March 2012 and October 2022 that explicitly aimed to emulate a target trial of a health or medical intervention. Two reviewers double-screened and -extracted data on study characteristics, key predefined components of the target trial protocol and its emulation (eligibility criteria, treatment strategies, treatment assignment, outcome[s], follow-up, causal contrast[s], and analysis plan), and other items related to the target trial emulation. Findings: A total of 200 studies that explicitly aimed to emulate a target trial were included. These studies included 26 subfields of medicine, and 168 (84%) were published from January 2020 to October 2022. The aim to emulate a target trial was explicit in 70 study titles (35%). Forty-three studies (22%) reported use of a published reporting guideline (eg, Strengthening the Reporting of Observational Studies in Epidemiology). Eighty-five studies (43%) did not describe all key items of how the target trial was emulated and 113 (57%) did not describe the protocol of the target trial and its emulation. Conclusion and Relevance: In this systematic review of 200 studies that explicitly aimed to emulate a target trial, reporting of how the target trial was emulated was inconsistent. A reporting guideline for studies explicitly aiming to emulate a target trial may improve the reporting of the target trial protocols and other aspects of these emulation attempts.

The smallest worthwhile effect on pain intensity of nonsteroidal anti-inflammatory drugs and exercise therapy for acute and chronic low back pain: a benefit-harm trade-off study.

QUESTION: What are the smallest worthwhile effects of nonsteroidal anti-inflammatory drugs (NSAIDs) for people with acute and chronic low back pain (LBP)? What is the smallest worthwhile effect of individualised exercise for people with chronic LBP compared with no intervention? DESIGN: Benefit-harm trade-off study. PARTICIPANTS: Participants were recruited by advertisement on social media and included if they were English-speaking adults in Australia who had non-specific LBP. OUTCOME MEASURE: Pain intensity. RESULTS: A total of 116 people with acute LBP and 230 people with chronic LBP were recruited. For acute LBP, the smallest worthwhile effect of NSAIDs additional to no intervention was a 30% (IQR 10 to 40%) reduction in pain intensity. For chronic LBP, the smallest worthwhile effect of NSAIDs additional to no intervention was a 27.5% (IQR 10 to 50%) reduction in pain intensity. For chronic LBP, the smallest worthwhile effect of exercise additional to no intervention was a 20% (IQR 10 to 40%) reduction in pain intensity. There were small associations between baseline pain, duration of pain and level of exercise and the smallest worthwhile effect of NSAIDs for acute LBP. There were no other clear associations. CONCLUSIONS: For people with LBP, the smallest worthwhile effect of exercise and NSAIDs additional to no intervention is approximately a 20 to 30% reduction in pain. These results can inform the interpretation of the effects of NSAIDs and exercise in randomised trials and meta-analyses, incorporating consumers' perspectives. Further research on comparisons between different interventions and on other core LBP outcomes may inform decision-making. REGISTRATION: OSF osf.io/3erjx/.

Development of the TrAnsparent ReportinG of observational studies Emulating a Target trial (TARGET) guideline.

BACKGROUND: Observational studies are increasingly used to inform health decision-making when randomised trials are not feasible, ethical or timely. The target trial approach provides a framework to help minimise common biases in observational studies that aim to estimate the causal effect of interventions. Incomplete reporting of studies using the target trial framework limits the ability for clinicians, researchers, patients and other decision-makers to appraise, synthesise and interpret findings to inform clinical and public health practice and policy. This paper describes the methods that we will use to develop the TrAnsparent ReportinG of observational studies Emulating a Target trial (TARGET) reporting guideline. METHODS/DESIGN: The TARGET reporting guideline will be developed in five stages following recommended guidance. The first stage will identify target trial reporting practices by systematically reviewing published studies that explicitly emulated a target trial. The second stage will identify and refine items to be considered for inclusion in the TARGET guideline by consulting content experts using sequential online surveys. The third stage will prioritise and consolidate key items to be included in the TARGET guideline at an in-person consensus meeting of TARGET investigators. The fourth stage will produce and pilot-test both the TARGET guideline and explanation and elaboration document with relevant stakeholders. The fifth stage will disseminate the TARGET guideline and resources via journals, conferences and courses. ETHICS AND DISSEMINATION: Ethical approval for the survey has been attained (HC220536). The TARGET guideline will be disseminated widely in partnership with stakeholders to maximise adoption and improve reporting of these studies.

Pain catastrophising and kinesiophobia mediate pain and physical function improvements with Pilates exercise in chronic low back pain: a mediation analysis of a randomised controlled trial.

QUESTION: How much are the reductions in pain intensity and improvements in physical function from Pilates exercise mediated by changes in pain catastrophising and kinesiophobia? DESIGN: This was a secondary causal mediation analysis of a four-arm randomised controlled trial testing Pilates exercise dosage (once, twice or thrice per week) against a booklet control. PARTICIPANTS: Two hundred and fifty-five people with chronic low back pain. DATA ANALYSIS: All analyses were conducted in R software (version 4.1.2) following a preregistered analysis plan. A directed acyclic graph was constructed to identify potential pre-treatment mediator-outcome confounders. For each mediator model, we estimated the intervention-mediator effect, the mediator-outcome effect, the total natural indirect effect (TNIE), the pure natural direct effect (PNDE), and the total effect (TE). RESULTS: Pain catastrophising mediated the effect of Pilates exercise compared with control on the outcomes pain intensity (TNIE MD -0.21, 95% CI -0.47 to -0.03) and physical function (TNIE MD -0.64, 95% CI -1.20 to -0.18). Kinesiophobia mediated the effect of Pilates exercise compared with control on the outcomes pain intensity (TNIE MD -0.31, 95% CI -0.68 to -0.02) and physical function (TNIE MD -1.06, 95% CI -1.70 to -0.49). The proportion mediated by each mediator was moderate (21 to 55%). CONCLUSION: Reductions in pain catastrophising and kinesiophobia partially mediated the pathway to improved pain intensity and physical function when using Pilates exercise for chronic low back pain. These psychological components may be important treatment targets for clinicians and researchers to consider when prescribing exercise for chronic low back pain.

Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews.

BACKGROUND: Complex regional pain syndrome (CRPS) is a chronic pain condition that usually occurs in a limb following trauma or surgery. It is characterised by persisting pain that is disproportionate in magnitude or duration to the typical course of pain after similar injury. There is currently no consensus regarding the optimal management of CRPS, although a broad range of interventions have been described and are commonly used. This is the first update of the original Cochrane review published in Issue 4, 2013. OBJECTIVES: To summarise the evidence from Cochrane and non-Cochrane systematic reviews of the efficacy, effectiveness, and safety of any intervention used to reduce pain, disability, or both, in adults with CRPS. METHODS: We identified Cochrane reviews and non-Cochrane reviews through a systematic search of Ovid MEDLINE, Ovid Embase, Cochrane Database of Systematic Reviews, CINAHL, PEDro, LILACS and Epistemonikos from inception to October 2022, with no language restrictions. We included systematic reviews of randomised controlled trials that included adults (≥18 years) diagnosed with CRPS, using any diagnostic criteria.  Two overview authors independently assessed eligibility, extracted data, and assessed the quality of the reviews and certainty of the evidence using the AMSTAR 2 and GRADE tools respectively. We extracted data for the primary outcomes pain, disability and adverse events, and the secondary outcomes quality of life, emotional well-being, and participants' ratings of satisfaction or improvement with treatment.  MAIN RESULTS: We included six Cochrane and 13 non-Cochrane systematic reviews in the previous version of this overview and five Cochrane and 12 non-Cochrane reviews in the current version. Using the AMSTAR 2 tool, we judged Cochrane reviews to have higher methodological quality than non-Cochrane reviews. The studies in the included reviews were typically small and mostly at high risk of bias or of low methodological quality. We found no high-certainty evidence for any comparison.  There was low-certainty evidence that bisphosphonates may reduce pain intensity post-intervention (standardised mean difference (SMD) -2.6, 95% confidence interval (CI) -1.8 to -3.4, P = 0.001; I2 = 81%; 4 trials, n = 181) and moderate-certainty evidence that they are probably associated with increased adverse events of any nature (risk ratio (RR) 2.10, 95% CI 1.27 to 3.47; number needed to treat for an additional harmful outcome (NNTH) 4.6, 95% CI 2.4 to 168.0; 4 trials, n = 181).  There was moderate-certainty evidence that lidocaine local anaesthetic sympathetic blockade probably does not reduce pain intensity compared with placebo, and low-certainty evidence that it may not reduce pain intensity compared with ultrasound of the stellate ganglion. No effect size was reported for either comparison. There was low-certainty evidence that topical dimethyl sulfoxide may not reduce pain intensity compared with oral N-acetylcysteine, but no effect size was reported. There was low-certainty evidence that continuous bupivacaine brachial plexus block may reduce pain intensity compared with continuous bupivacaine stellate ganglion block, but no effect size was reported. For a wide range of other commonly used interventions, the certainty in the evidence was very low and provides insufficient evidence to either support or refute their use. Comparisons with low- and very low-certainty evidence should be treated with substantial caution. We did not identify any RCT evidence for routinely used pharmacological interventions for CRPS such as tricyclic antidepressants or opioids. AUTHORS' CONCLUSIONS: Despite a considerable increase in included evidence compared with the previous version of this overview, we identified no high-certainty evidence for the effectiveness of any therapy for CRPS. Until larger, high-quality trials are undertaken, formulating an evidence-based approach to managing CRPS will remain difficult. Current non-Cochrane systematic reviews of interventions for CRPS are of low methodological quality and should not be relied upon to provide an accurate and comprehensive summary of the evidence.

Mechanisms of education and graded sensorimotor retraining in people with chronic low back pain: a mediation analysis.

ABSTRACT: An improved understanding of the biopsychosocial influences that contribute to and maintain pain has promoted the development of new efficacious treatments for chronic low back pain (CLBP). This study aimed to investigate the mechanisms of a new treatment-education and graded sensorimotor retraining-on pain and disability. We conducted a preplanned causal mediation analysis of a randomized clinical trial which allocated 276 participants with CLBP to 12 weekly clinical sessions of education and graded sensorimotor retraining (n = 138) or a sham and attention control (n = 138). Outcomes were pain intensity and disability, both assessed at 18 weeks. Hypothesized mediators included tactile acuity, motor coordination, back self-perception, beliefs about the consequences of back pain, kinesiophobia, pain self-efficacy, and pain catastrophizing, all assessed at the end of treatment (12 weeks). Four of 7 mechanisms (57%) mediated the intervention effect on pain; the largest mediated effects were for beliefs about back pain consequences (-0.96 [-1.47 to -0.64]), pain catastrophizing (-0.49 [-0.61 to -0.24]), and pain self-efficacy (-0.37 [-0.66 to -0.22]). Five of 7 mechanisms (71%) mediated the intervention effect on disability; the largest mediated effects were for beliefs about back pain consequences (-1.66 [-2.62 to -0.87]), pain catastrophizing (-1.06 [-1.79 to -0.53]), and pain self-efficacy (-0.84 [-1.89 to -0.45]). When all 7 mechanisms were considered simultaneously, the joint mediation effect explained most of the intervention effect for both pain and disability. Optimizing interventions to target beliefs about the consequences of back pain, pain catastrophizing, and pain self-efficacy is likely to lead to improved outcomes for people with CLBP.