The current state of knowledge on care for co-occurring chronic pain and opioid use disorder: A scoping review.

BACKGROUND AND AIMS: Opioid use disorder often co-occurs with chronic pain but assessment and treatment of these co-occurring disorders is complex. This review aims to identify current treatments and delivery models for co-occurring chronic pain and opioid use disorder (OUD) documented in the scientific literature. DESIGN: Scoping review. METHODS: The review was conducted in six databases in June 2022 (no time limit): CINAHL, PsycINFO, Web of Science, Cochrane, PubMed and Embase. The PRISMA-ScR checklist was used to guide reporting. RESULTS: Forty-seven publications addressing the issue of co-occurring chronic pain and OUD management were included. Randomized controlled trials provide evidence for the effectiveness of opioid agonist treatments (OAT) such as methadone or buprenorphine/naloxone, as well as for combining OAT with Mindfulness-Oriented Recovery Enhancement or cognitive behavioural therapy. A number of other pharmacological treatments (opioid and nonopioid), nonpharmacological treatments (e.g. physiotherapy) and service delivery models (e.g. simultaneous treatment of comorbidities, interdisciplinary and interprofessional collaboration) are also underlined. In most cases, authors recommend a combination of strategies to meet patient needs. CONCLUSIONS: The scoping review reveals gaps in evidence-based knowledge to effectively care for co-occurring chronic pain and OUD, but several experts recommend the uptake of known 'best' practices such as integrated treatment of the multiple biopsychosocial dimensions of the co-occurring disorders as well as collaborative interdisciplinary work. CLINICAL RELEVANCE: Improving services is dependent on alleviating barriers such as working in silos, the costs associated with nonpharmacological treatments, and the double stigma associated with pain in people with a substance use disorder.

Efficacy of interventions targeted at physician prescribers of opioids for chronic non-cancer pain: an overview of systematic reviews.

BACKGROUND: To combat the opioid crisis, interventions targeting the opioid prescribing behaviour of physicians involved in the management of patients with chronic non-cancer pain (CNCP) have been introduced in clinical settings. An integrative synthesis of systematic review evidence is required to better understand the effects of these interventions. Our objective was to synthesize the systematic review evidence on the effect of interventions targeting the behaviours of physician opioid prescribers for CNCP among adults on patient and population health and prescriber behaviour. METHODS: We searched MEDLINE, Embase, and PsycInfo via Ovid; the Cochrane Database of Systematic Reviews; and Epistemonikos. We included systematic reviews that evaluate any type of intervention aimed at impacting opioid prescriber behaviour for adult CNCP in an outpatient setting. RESULTS: We identified three full texts for our review that contained 68 unique primary studies. The main interventions we evaluated were structured prescriber education (one review) and prescription drug monitoring programmes (PDMPs) (two reviews). Due to the paucity of data available, we could not determine with certainty that education interventions improved outcomes in deprescribing. There is some evidence that PDMPs decrease the number of adverse opioid-related events, increase communication among healthcare workers and patients, modify healthcare practitioners' approach towards their opioid prescribed patients, and offer more chances for education and counselling. CONCLUSIONS: Our overview explores the possibility of PDMPs as an opioid deprescribing intervention and highlights the need for more high-quality primary research on this topic.

One session of repetitive transcranial magnetic stimulation induces mild and transient analgesic effects among female individuals with painful temporomandibular disorders.

OBJECTIVE: Temporomandibular disorders (TMD) are characterised by chronic pain and dysfunction in the jaw joint and masticatory muscles. Repetitive transcranial magnetic stimulation (rTMS) has emerged as a potential non-invasive treatment for chronic pain; however, its effectiveness in individuals with TMD has not been thoroughly investigated. This study aimed to evaluate the immediate and sustained (over seven consecutive days) effects of a single session of active rTMS compared to sham stimulation on pain intensity and pain unpleasantness in individuals with TMD. METHODS: A randomised, double-blind, sham-controlled trial enrolled 41 female participants with chronic TMD. Pain intensity and pain unpleasantness were assessed immediately pre- and post-intervention, as well as twice daily for 21 days using electronic diaries. Secondary outcomes included pain interference, sleep quality, positive and negative affect and pain catastrophizing. Adverse effects were monitored. Repeated measures ANOVA and multilevel modelling regression analyses were employed for data analysis. RESULT: Active rTMS demonstrated a significant immediate mild reduction in pain intensity and pain unpleasantness compared to sham stimulation. However, these effects were not sustained over the 7-day post-intervention period. No significant differences were observed between interventions for pain interference, sleep quality and negative affect. A minority of participants reported minor and transient side effects, including headaches and fatigue. CONCLUSION: A single session of active rTMS was safe and led to immediate mild analgesic effects in individuals with TMD compared to sham stimulation. However, no significant differences were observed between interventions over the 7-day post-intervention period. Based on this study, rTMS stimulation appears to be a promising safe approach to be tested in TMD patients with longer stimulation protocols.

A Descriptive Analysis of Adverse Event Reports from the Quebec Cannabis Registry.

INTRODUCTION: Published data on the safety of natural medical cannabis (MC) when used in the real-world clinical practice setting are lacking. This study aimed to describe adverse events (AEs) reported across three years following MC initiation. METHODS: The Quebec Cannabis Registry (QCR) was a prospective registry of adults enrolled through participating physicians when they initiated MC between May 2015 and October 2018. Follow-up ended at MC discontinuation, loss to follow-up, three years, or end of data collection (May 2019). Data were collected at baseline and at follow-up visits every three months for the first two years, then once in the third year. Physicians filled adverse event (AE) reports, which were coded using MedDRA® preferred terms (PTs), and descriptive analyses were conducted. RESULTS: A total of 2991 patients were enrolled (mean age 50.9 years, 50.2% females). During follow-up, 108 patients (3.6%) experienced moderate or severe AEs, yielding 111 AE reports (three patients had two reports) and 214 AEs (average 1.9 AEs per report). Mild AEs were recorded as a reason for MC discontinuation for nine patients, but no AE reports were available. The most common PTs for ingested MC (62 reports) were dizziness (12.9%), nausea (11.3%), somnolence (9.7%), and vomiting (8.1%), and for inhaled MC (23 reports), headache (13.0%) was the most common. The most frequent PTs associated with tetrahydrocannabinol (THC)-dominant MC (25 reports) were dizziness and somnolence (12.0% each); for cannabidiol (CBD)-dominant MC (20 reports), vomiting (20.0%) was most common; and dizziness (17.2%), nausea (13.8%), somnolence (10.3%), and headache (8.6%) were the most frequent for balanced MC (58 reports). CONCLUSION: No new safety concerns were identified relative to the published literature, although notable differences in AE profile between modes of administration and cannabinoid content ratios should be considered by health professionals. Further work identifying and managing risk factors for AEs is warranted to maintain a favorable benefit-risk balance for MC.

Trajectories of opioid consumption as predictors of patient-reported outcomes among individuals attending multidisciplinary pain treatment clinics.

PURPOSE: This study aimed to identify opioid consumption trajectories among persons living with chronic pain (CP) and put them in relation to patient-reported outcomes 6 months after initiating multidisciplinary pain treatment. METHODS: This study used data from the Quebec Pain Registry (2008-2014) linked to longitudinal Quebec health insurance databases. We included adults diagnosed with CP and covered by the Quebec public prescription drug insurance plan. The daily cumulative opioid doses in the first 6 months after initiating multidisciplinary pain treatment were transformed into morphine milligram equivalents. An individual-centered approach involving principal factor and cluster analyses applied to longitudinal statistical indicators of opioid use was conducted to classify trajectories. Multivariate regression models were applied to evaluate the associations between trajectory group membership and outcomes at 6-month follow-up (pain intensity, pain interference, depression, and physical and mental health-related quality of life). RESULTS: We identified three trajectories of opioid consumption: "no or very low and stable" opioid consumption (n = 2067, 96.3%), "increasing" opioid consumption (n = 40, 1.9%), and "decreasing" opioid consumption (n = 39, 1.8%). Patients in the "no or very low and stable" trajectory were less likely to be current smokers, experience polypharmacy, use opioids or benzodiazepine preceding their first visit, or experience pain interference at treatment initiation. Patients in the "increasing" opioid consumption group had significantly greater depression scores at 6-month compared to patients in the "no or very low and stable" trajectory group. CONCLUSION: Opioid consumption trajectories do not seem to be important determinants of most PROs 6 months after initiating multidisciplinary pain treatment.

The Impact of Sleep Disturbances on Endogenous Pain Modulation: A Systematic Review and Meta-Analysis.

The bidirectional relationship between sleep and pain problems has been extensively demonstrated but despite all the accumulating evidence, their shared mechanisms are currently not fully understood. This review examined the association between sleep disturbances, defined as a broad array of sleep-related outcomes (eg, poor quality, short duration, insomnia), and endogenous pain modulation (EPM) in healthy and clinical populations. Our search yielded 6,151 references, and 37 studies met the eligibility criteria. Qualitative results showed mixed findings regarding the association between sleep disturbances and temporal summation of pain (TSP) and conditioned pain modulation (CPM), with poor sleep more commonly associated with decreased pain inhibition in both populations. Quantitative results indicated that such associations were not statistically significant, neither in healthy populations when EPM outcomes were assessed for changes pre-/post-sleep intervention (TSP: .31 [95%CI: -.30 to .92]; P = .321; CPM: .40 [95%CI: -.06 to .85] P = .088) nor in clinical populations when such association was assessed via correlation (TSP: -.00 [95%CI: -.22 to .21] P = .970; CPM: .12 [95%CI: -.05 to .29]; P = .181). For studies that reported results by sex, meta-analysis showed that experimental sleep disturbances impaired pain inhibition in females (1.43 [95%CI: .98-1.88]; P < .001) but not in males (-.30 [95%CI: -2.69 to 1.60]; P = .760). Only one study investigating the association between sleep disturbances and offset analgesia was identified, while no studies assessing spatial summation of pain were found. Overall, this review provides a comprehensive overview of the association between sleep disturbances and EPM function, emphasizing the need for further investigation to clarify specific mechanisms and phenotypic subtypes. PERSPECTIVES: This review shines a light on the association between sleep disturbances and endogenous pain modulation function. Qualitatively, we found a frequent association between reduced sleep quality and impaired pain inhibition. However, quantitatively such an association was not corroborated. Sex-specific effects were observed, with females presenting sleep-related impaired pain inhibition but not males.

A prognostic risk score for development and spread of chronic pain.

Chronic pain is a complex condition influenced by a combination of biological, psychological and social factors. Using data from the UK Biobank (n = 493,211), we showed that pain spreads from proximal to distal sites and developed a biopsychosocial model that predicted the number of coexisting pain sites. This data-driven model was used to identify a risk score that classified various chronic pain conditions (area under the curve (AUC) 0.70-0.88) and pain-related medical conditions (AUC 0.67-0.86). In longitudinal analyses, the risk score predicted the development of widespread chronic pain, the spreading of chronic pain across body sites and high-impact pain about 9 years later (AUC 0.68-0.78). Key risk factors included sleeplessness, feeling 'fed-up', tiredness, stressful life events and a body mass index >30. A simplified version of this score, named the risk of pain spreading, obtained similar predictive performance based on six simple questions with binarized answers. The risk of pain spreading was then validated in the Northern Finland Birth Cohort (n = 5,525) and the PREVENT-AD cohort (n = 178), obtaining comparable predictive performance. Our findings show that chronic pain conditions can be predicted from a common set of biopsychosocial factors, which can aid in tailoring research protocols, optimizing patient randomization in clinical trials and improving pain management.

Medicinal Cannabis Use for Rheumatic Conditions in the US Versus Canada: Rationale for Use and Patient-Health Care Provider Interactions.

OBJECTIVE: Understanding how medical cannabis (MC) use is integrated into medical practice for rheumatic disease management is essential. We characterized rationale for MC use, patient-physician interactions around MC, and MC use patterns among people with rheumatic conditions in the US and Canada. METHODS: We surveyed 3406 participants with rheumatic conditions in the US and Canada, with 1727 completing the survey (50.7% response rate). We assessed disclosure of MC use to health care providers, MC authorization by health care providers, and MC use patterns and investigated factors associated with MC disclosure to health care providers in the US versus Canada. RESULTS: Overall, 54.9% of US respondents and 78.0% of Canadians reported past or current MC use, typically because of inadequate symptom relief from other medications. Compared to those in Canada, fewer US participants obtained MC licenses, disclosed MC use to their health care providers, or asked advice on how to use MC (all P values <0.001). Overall, 47.4% of Canadian versus 28.2% of US participants rated their medical professionals as their most trusted information source. MC legality in state of residence was associated with 2.49 greater odds of disclosing MC use to health care providers (95% confidence interval: 1.49-4.16, P < 0.001) in the US, whereas there were no factors associated with MC disclosure in Canada. Our study is limited by our convenience sampling strategy and cross-sectional design. CONCLUSION: Despite widespread availability, MC is poorly integrated into rheumatic disease care, with most patients self-directing use with minimal or no clinical oversight. Concerted efforts to integrate MC into education and clinical policy is critical.

The interplay between symptoms of insomnia and pain in people with osteoarthritis: A narrative review of the current evidence.

Osteoarthritis (OA) is a leading cause of disability worldwide and clinical pain is the major symptom of OA. This clinical OA-related pain is firmly associated with symptoms of insomnia, which are reported in up to 81% of people with OA. Since understanding the association between both symptoms is critical for their appropriate management, this narrative review synthesizes the existing evidence in people with OA on i) the mechanisms underlying the association between insomnia symptoms and clinical OA-related pain, and ii) the effectiveness of conservative non-pharmacological treatments on insomnia symptoms and clinical OA-related pain. The evidence available identifies depressive symptoms, pain catastrophizing and pain self-efficacy as mechanisms partially explaining the cross-sectional association between insomnia symptoms and pain in people with OA. Furthermore, in comparison to treatments without a specific insomnia intervention, the ones including an insomnia intervention appear more effective for improving insomnia symptoms, but not for reducing clinical OA-related pain. However, at a within-person level, treatment-related positive effects on insomnia symptoms are associated with a long-term pain reduction. Future longitudinal prospective studies offering fundamental insights into neurobiological and psychosocial mechanisms explaining the association between insomnia symptoms and clinical OA-related pain will enable the development of effective treatments targeting both symptoms.

The Association Between Perceived Injustice and Opioid Craving in Patients With Chronic Pain: The Mediating Role of Daily Pain Intensity, Negative Affect, and Catastrophizing.

OBJECTIVES: The first objective of this study was to examine the association between perceived injustice and opioid craving in patients with chronic pain who are prescribed opioids. We also examined whether pain intensity, negative affect, or catastrophizing mediated this association. METHODS: In this longitudinal diary study, patients (n = 103) completed a questionnaire assessing perceived injustice and then completed daily measures of pain intensity, negative affect, catastrophizing, and opioid craving for 14 consecutive days. RESULTS: A significant association was found between perceived injustice and opioid craving ( P < 0.01), with higher levels of perceived injustice being associated with heightened levels of opioid craving. A 2-1-1 multilevel mediation analysis indicated that the association between perceived injustice and craving was significantly mediated by catastrophizing ( P < 0.05). CONCLUSIONS: The present study provides new insights into the factors that might contribute to opioid craving in patients with chronic pain. Our findings suggest that perceived injustice might lead to increased catastrophizing and, in turn, heightened daily levels of opioid craving. These findings could have implications for chronic pain management clinicians who prescribe opioids.

Predictors of Pain Reduction Among Fibromyalgia Patients Using Medical Cannabis: A Long-Term Prospective Cohort Study.

OBJECTIVE: Many patients with fibromyalgia (FM) report using cannabis as a strategy to improve pain. Given that pain often co-occurs with symptoms of anxiety and depression (i.e., negative affect) and sleep problems among patients with FM, improvements in these symptoms might indirectly contribute to reductions in pain intensity following cannabis use. The main objective of the study was to examine whether changes in pain intensity following initiation of medical cannabis among patients with FM could be attributed to concurrent changes (i.e., reductions) in negative affect and sleep problems. METHODS: This was a 12-month prospective cohort study among patients with FM (n = 323) initiating medical cannabis under the care of physicians. Patients were assessed at baseline, and follow-up assessment visits occurred every 3 months after initiation of medical cannabis. Patients' levels of pain intensity, negative affect, and sleep problems were assessed across all visits. RESULTS: Multilevel mediation analyses indicated that reductions in patients' levels of pain intensity were partly explained by concurrent reductions in sleep problems and negative affect (both P < 0.001). This remained significant even when accounting for patients' baseline characteristics or changes in medical cannabis directives over time (all P > 0.05). CONCLUSION: Our findings provide preliminary insight into the potential mechanisms of action underlying pain reductions among patients with FM who are using medical cannabis. Given the high attrition rate (i.e., 75%) observed in the present study at 12 months, our findings cannot be generalized to all patients with FM who are using medical cannabis.

The Quebec Cannabis Registry: Investigating the Safety and Effectiveness of Medical Cannabis.

Objective: To investigate the safety and effectiveness of medical cannabis (MC) in the real-world clinical practice setting. Design: A 4-year prospective noncomparative registry of adult patients who initiated MC for a variety of indications. This paper reports on patients followed for up to 12 months, with interim visits at 3, 6, and 9 months after enrollment. Setting: Public or private outpatient clinics certified to authorize MC in the province of Quebec, Canada. Participants: Overall, 2991 adult (age ≥18 years) patients (mean age 51 years; 50.2% women) were enrolled between May 2015 and October 2018, with the last follow-up ending in May 2019. Interventions/Exposures: Cannabis products (dried, oil, or other) purchased from a Canadian licensed cannabis producer as authorized by physicians. Main Outcome Measures: The primary outcomes were self-reported pain severity, interference and relief (Brief Pain Inventory [BPI]), symptoms using the Revised Edmonton Symptom Assessment System (ESAS-r) and health-related quality of life dimensions (EQ-5D-5L) at baseline and each follow-up visit. The secondary outcomes were self-reported adverse events (AEs) and characteristics of cannabis treatment. Results: All patient-reported outcomes (BPI, ESAS-r, and EQ-5D-5L) showed a statistically significant improvement at 3 months (all p<0.01), which was maintained or further improved (for pain interference, tiredness, and well-being) over the remainder of the 12-month follow-up. Results also revealed clinically significant improvements in pain interference and tiredness, anxiety, and well-being from baseline. There were 79 AE reports (77 patients), 16 met the regulatory definition of seriousness, in which only 8 AEs were certainly or probably related to MC. Conclusions: MC directed by physicians appears to be safe and effective within 3 months of initiation for a variety of medical indications.

Interventions for physician prescribers of opioids for chronic non-cancer pain: protocol for an overview of systematic reviews.

INTRODUCTION: Interventions targeting behaviours of physician prescribers of opioids for chronic non-cancer pain have been introduced to combat the opioid crisis. Systematic reviews have evaluated effects of specific interventions (eg, prescriber education, prescription drug monitoring programmes) on patient and population health outcomes and prescriber behaviour. Integration of findings across intervention types is needed to better understand the effects of prescriber-targeted interventions. METHODS AND ANALYSIS: We will conduct an overview of systematic reviews. Eligible systematic reviews will include primary studies that evaluated any intervention targeting the behaviours of physician prescribers of opioids for chronic non-cancer pain in an outpatient or mixed setting, compared with no intervention, usual practice or another active or control intervention. Eligible outcomes will pertain to the intervention effect on patient and population health or opioid prescribing behaviour. We will search MEDLINE, Embase and PsycInfo via Ovid; the Cochrane Database of Systematic Reviews and Epistemonikos from inception. We will also hand search reference lists for additional publications. Screening and data extraction will be conducted independently by two reviewers, with disagreements resolved by consensus or consultation with a third reviewer. The risk of bias of included systematic reviews will be assessed in duplicate by two reviewers using the Risk of Bias in Systematic Reviews tool. Results will be synthesised narratively by intervention type and grouped by outcome. To assist with result interpretation, outcomes will be labelled as intended or unintended according to intervention objectives, and as positive, negative, evidence of no effect or inconclusive evidence according to effect on the population (for patient and population health outcomes) or intervention objectives (for prescriber outcomes). ETHICS AND DISSEMINATION: As the proposed study will use published data, ethics approval is not required. Dissemination of results will be achieved through publication of a manuscript in a peer-reviewed journal and conference presentations. PROSPERO REGISTRATION NUMBER: CRD42020156815.

Multimodal prediction of pain and functional outcomes 6 months following total knee replacement: a prospective cohort study.

BACKGROUND: Knee osteoarthritis (OA) is among the most common and disabling persistent pain conditions, with increasing prevalence and impact around the globe. In the U.S., the rising prevalence of knee OA has been paralleled by an increase in annual rates of total knee arthroplasty (TKA), a surgical treatment option for late-stage knee OA. While TKA outcomes are generally good, post-operative trajectories of pain and functional status vary substantially; a significant minority of patients report ongoing pain and impaired function following TKA. A number of studies have identified sets of biopsychosocial risk factors for poor post-TKA outcomes (e.g., comorbidities, negative affect, sensory sensitivity), but few prospective studies have systematically evaluated the unique and combined influence of a broad array of factors. METHODS: This multi-site longitudinal cohort study investigated predictors of 6-month pain and functional outcomes following TKA. A wide spectrum of relevant biopsychosocial predictors was assessed preoperatively by medical history, patient-reported questionnaire, functional testing, and quantitative sensory testing in 248 patients undergoing TKA, and subsequently examined for their predictive capacity. RESULTS: The majority of patients had mild or no pain at 6 months, and minimal pain-related impairment, but approximately 30% reported pain intensity ratings of 3/10 or higher. Reporting greater pain severity and dysfunction at 6 months post-TKA was predicted by higher preoperative levels of negative affect, prior pain history, opioid use, and disrupted sleep. Interestingly, lower levels of resilience-related "positive" psychosocial characteristics (i.e., lower agreeableness, lower social support) were among the strongest, most consistent predictors of poor outcomes in multivariable linear regression models. Maladaptive profiles of pain modulation (e.g., elevated temporal summation of pain), while not robust unique predictors, interacted with psychosocial risk factors such that the TKA patients with the most pain and dysfunction exhibited lower resilience and enhanced temporal summation of pain. CONCLUSIONS: This study underscores the importance of considering psychosocial (particularly positively-oriented resilience variables) and sensory profiles, as well as their interaction, in understanding post-surgical pain trajectories.

Effectiveness of Interventions for Prevention of Common Infections Among Opioid Users: A Systematic Review of Systematic Reviews.

Background: The North American opioid crisis is marked by high opioid-related mortality and morbidity, including opioid use-associated infections (OUAIs). Users of pharmaceutical and non-pharmaceutical opioids are at an increased risk of acquiring hepatitis C (HCV), human immunodeficiency virus (HIV), and other infections. No high-level evidence, however, has been synthesized regarding effectiveness of interventions to prevent OUAIs in legal, and illegal/mixed opioid users. The aim of the study is to synthesize available systematic review (SR)-level evidence on the scope and effectiveness of interventions to prevent OUAIs among opioid users. Methods: A SR of SRs approach was applied. We searched PubMed, Embase, PsycINFO, Cochrane Database of Systematic Reviews, Epistemonikos and Google Scholar from inception to September 2020. Data selection and extraction were performed independently by three researchers. Risk of bias and quality of evidence were assessed using the AMSTAR2 tool. Results were narratively synthesized. Strength of evidence for each category was reported. Results: Eleven of twelve identified SRs included interventions to prevent HCV/HIV transmission in persons who inject drugs (PWID), including opioids. One SR evaluated interventions to prevent recurrent infectious endocarditis. There was sufficient and tentative SR of SRs-level evidence for the effectiveness of opioid substitution therapy (OST) in preventing HIV and HCV, respectively. We found tentative evidence to support effectiveness of needle/syringe exchange programs (NSP) in HIV prevention, and sufficient evidence to support effectiveness of the combined OST and NSP in HCV prevention. There was insufficient SR-level evidence to support or discount effectiveness of other interventions to prevent OUAIs. No SR focused on non-PWID populations. Conclusion: SR-level evidence supports the use of OST, NSP, and combined interventions for the reduction of HCV and HIV transmission in PWID. More research on prevention of other OUAIs and on prevention of OUAIs in non-PWID populations is urgently needed. Systematic Review Registration: Registered in PROSPERO on July 30, 2020. https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=195929, identifier: #195929.

French-Canadian Translation and Cultural Adaptation of the Clinical Opiate Withdrawal Scale: The COWS-FC.

OBJECTIVE: The main objective of the present study was to develop a French-Canadian translation and adaptation of the COWS (i.e., the COWS-FC) for the assessment of opioid withdrawal symptoms in clinical and research settings. METHODS: The French-Canadian translation and cultural adaptation of the COWS was performed following guidelines for the translation and cross-cultural adaptation of self-report measures. The steps consisted of (1) initial translation from English to French, (2) synthesis of the translation, (3) back-translation from French to English, (4) expert committee meeting, (5) test of the prefinal version among healthcare professionals and (6) review of final version by the expert committee. The expert committee considered four major areas where the French-Canadian version should achieve equivalence with the original English-version of the COWS. These areas were (1) semantic equivalence; (2) idiomatic equivalence; (3) experiential equivalence and (4) conceptual equivalence. RESULTS: Rigorous steps based on the guidelines for the translation and cultural adaptation of assessment tools were followed, which led to a semantically equivalent version of the COWS. After a pretest among healthcare professionals, members from the expert committee agreed upon slight modifications to the French-Canadian version of the COWS to yield a final COWS-FC version. CONCLUSIONS: A French-Canadian translation and adaptation of the COWS (i.e., the COWS-FC) was developed. The COWS-FC could be used for the assessment of opioid withdrawal symptoms in clinical and research settings.

Temporomandibular disorders cases with high-impact pain are more likely to experience short-term pain fluctuations.

Temporomandibular disorders (TMD) patients can present clinically significant jaw pain fluctuations which can be debilitating and lead to poor global health. The Graded Chronic Pain Scale evaluates pain-related disability and its dichotomous grading (high/low impact pain) can determine patient care pathways and in general high-impact pain patients have worse treatment outcomes. Individuals with low-impact TMD pain are thought to have better psychosocial functioning, more favorable disease course, and better ability to control pain, while individuals with high-impact pain can present with higher levels of physical and psychological symptoms. Thereby, there is reason to believe that individuals with low- and high-impact TMD pain could experience different pain trajectories over time. Our primary objective was to determine if short-term jaw pain fluctuations serve as a clinical marker for the impact status of TMD pain. To this end, we estimated the association between high/low impact pain status and jaw pain fluctuations over three visits (≤ 21-day-period) in 30 TMD cases. Secondarily, we measured the association between jaw pain intensity and pressure pain thresholds (PPT) over the face and hand, the latter measurements compared to matched pain-free controls (n = 17). Jaw pain fluctuations were more frequent among high-impact pain cases (n = 15) than low-impact pain cases (n = 15) (OR 5.5; 95% CI 1.2, 26.4; p value = 0.033). Jaw pain ratings were not associated with PPT ratings (p value > 0.220), suggesting different mechanisms for clinical versus experimental pain. Results from this proof-of-concept study suggest that targeted treatments to reduce short-term pain fluctuations in high-impact TMD pain is a potential strategy to achieve improved patient perception of clinical pain management outcomes.