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Background and Objective: A major concern with cannabis-based medicines (CbM) and medical cannabis (MC) is the risk of abuse and dependence. The face validity of the International Classification of Diseases (ICD-10) criteria for cannabis dependence in patients prescribed CbM for chronic pain has not been assessed., Databases and Data Treatment: Physicians from Canada, Germany and Israel were recruited via the mailing lists of national pain societies. To be eligible, physicians had to have prescribed CbM for chronic pain treatment in the past 12 months. Participants were asked to rate the appropriateness of items adapted from the substance use module of the Composite International Diagnostic Interview Version 3.0 to assess dependence in the context of chronic pain treatment with CbM and the appropriateness of two additional items. In case of disagreement, participants were asked to give reasons. Furthermore, they were asked to suggest potential additional criteria., Results: On average 69.0% of 178 participating physicians indicated agreement with the appropriateness of the ICD-10 criteria, while 20.6% indicated disagreement. The highest disagreement rate was observed for the item on repeated use despite legal problems (35.4% disagreement or strong disagreement). Reasons for disagreement were summarized into six content categories using qualitative methods of analysis. Additional criteria suggested by participants were summarized into 10 content categories., Conclusions: A collaboration of psychiatrists and pain physicians is required to define criteria and develop instruments to capture abuse and dependence of CbM in chronic pain patients., Significance: Sixty-nine per cent of 178 pain medicine physicians in Canada, Germany and Israel who participated in a survey on the appropriateness of the ICD-10 criteria for cannabis abuse and dependence for patients prescribed cannabis-derived products for chronic pain assessed the criteria as appropriate, whereas 20.6% deemed the criteria as not appropriate., (© 2023 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation - EFIC ®.)

The field of chronic pain medicine is currently facing enormous challenges. The incidence of chronic pain is increasing worldwide, particularly in the developed world. As a result, chronic pain is imposing a growing burden on Western societies in terms of cost of medical care and lost productivity. This burden is exacerbated by the fact that despite research efforts and a huge expenditure on treatment for chronic pain, clinicians have no highly effective treatments or definitive diagnostic measures for patients. The lack of an objective measure for pain impedes basic research into the biological and psychological mechanisms of chronic pain and clinical research into treatment efficacy. The development of objective measurements of pain and ability to predict treatment responses in the individual patient is critical to improving pain management. Finally, pain medicine must embrace the development of a new evidence-based therapeutic model that recognizes the highly individual nature of responsiveness to pain treatments, integrates bio-psycho-behavioural approaches, and requires proof of clinical effectiveness for the various treatments we offer our patients. In the long-term these approaches will contribute to providing better diagnoses and more effective treatments to lessen the current challenges in pain medicine., (© 2013 European Federation of International Association for the Study of Pain Chapters.)

Background: Women undergoing breast cancer surgery frequently experience postsurgical pain and fatigue, which reduces their quality of life. Although psychological factors have been shown to play a role in predicting postsurgical outcomes, the subacute recovery phase often remains underexplored. In this secondary analysis of data from a randomised controlled trial, we sought to investigate the predictive role of negative affect and experiential avoidance on postsurgical symptoms during both acute and subacute recovery., Methods: From the initial sample, 189 women who met the inclusion criteria completed the Acceptance and Action Questionnaire (AAQ-II) before surgery to assess levels of negative affect and experiential avoidance. Postsurgical pain and fatigue were measured at hospital discharge and again 3-4 weeks later using a 100 mm Visual Analogue Scale (VAS)., Results: Bivariate linear regression analyses revealed that higher presurgical negative affect and experiential avoidance significantly predicted increased levels of all acute and subacute postsurgical symptoms (all p ≤ 0.027). After adjusting for covariates in multivariate regression analyses, the AAQ-II remained a predictor of acute pain unpleasantness (p = 0.011) and fatigue (p = 0.048), although the effect estimates were modest., Conclusions: These findings underscore the need to take psychological factors into account in treatment planning for acute postsurgical symptoms in order to develop more individualised approaches to optimise recovery for women undergoing breast cancer surgery., Significance: Women with higher levels of negative affect and experiential avoidance before undergoing breast cancer surgery appear to be at greater risk for experiencing heightened acute postsurgical pain and fatigue. The identification of these psychological predictors can help clinicians recognise individuals at risk for severe postoperative symptoms and develop targeted preventive and curative interventions to mitigate these symptoms and prevent them from becoming chronic., (© 2025 European Pain Federation ‐ EFIC ®.)

Background: Complex regional pain syndrome (CRPS) is a debilitating condition characterised by significant heterogeneity. Early diagnosis is critical, but limited data exists on the condition's early stages. This study aimed to characterise (very) early CRPS patients and explore potential subgroups to enhance understanding of its mechanisms., Methods: A total of 113 early CRPS patients were recruited, with 89 undergoing physical assessments. Data included demographic information, work-related factors, CRPS history and clinical features, body perception disturbances, quantitative sensory testing (QST), and a visuospatial attention task., Results: QST identified deficits in detecting thermal and mechanical stimuli, alongside increased sensitivity to thermal and blunt pressure painful stimuli. Participants reported body perception disturbances similar to those of persistent CRPS. Visuospatial biases were observed in two subgroups of patients. Latent class analysis (LCA) of 85 participants, based on five clinical parameters, identified four profiles: Mild, Moderate, Body Representation Disturbance (BRD), and Pressure Allodynia CRPS. The Mild and Moderate profiles were associated with higher-intensity trauma, with the latter showing worse outcomes. BRD and Pressure Allodynia CRPS followed mild trauma but exhibited the poorest outcomes. BRD CRPS displayed significant body perception disturbances, while Pressure Allodynia CRPS presented the highest sensitivity to pressure and psychosocial risk of chronification. Neither condition duration nor skin temperature effectively distinguished subgroups., Conclusions: These findings emphasise the heterogeneity within (very) early CRPS patients and support the absence of a minimum required duration prior to the CRPS diagnosis. Central/systemic mechanisms may play critical roles in severe cases., Significance: This study identifies distinct (very) early CRPS profiles, suggesting different pathophysiological mechanisms and challenging traditional classifications. It paves the way for improved diagnosis and tailored treatments., (© 2025 European Pain Federation ‐ EFIC ®.)

Background and Objective: Non-invasive neuromodulation techniques (NIN), such as transcranial Direct Current Stimulation (tDCS) and repetitive Transcranial Magnetic Stimulation (rTMS), have been extensively researched for their potential to alleviate pain by reversing neuroplastic changes associated with neuropathic pain (NP), a prevalent and complex condition. However, treating NP remains challenging due to the numerous variables involved, such as different techniques, dosages and aetiologies. It is necessary to provide insights for clinicians and public healthcare managers to support clinical decision-making. This umbrella review aims to consolidate existing evidence on the effectiveness of various NIN in managing chronic NP., Databases and Data Treatment: A systematic search was conducted in the PubMed/MEDLINE database, including meta-analyses of controlled trials comparing NIN techniques with sham interventions for NP treatment. The quality of included studies was assessed using the AMSTAR-2 tool and the GRADE system, with effect sizes adjusted to the standard mean difference (SMD)., Results: The review included 22 meta-analyses comprising 8151 participants from 214 controlled trials. The most investigated NIN techniques were tDCS and rTMS, with primary targets being the motor cortex and dorsolateral prefrontal cortex. The findings suggest that excitatory protocols, particularly high-frequency rTMS and anodal tDCS, are effective in reducing pain intensity in individuals with NP. However, the overall quality of evidence was rated low, primarily due to heterogeneity among studies and small sample sizes., Conclusion: NIN techniques show promise in managing NP, with potential benefits in pain reduction. However, further high-quality research is needed to establish optimal protocols and long-term effects., Significance Statement: This paper consolidates the evidence regarding non-invasive neuromodulation for the treatment of neuropathic pain, including differentiating the most effective techniques based on the aetiology of pain, and provides clinicians with easy access to this critical information. It also highlights key aspects that require further research in the field of non-invasive neuromodulation and neuropathic pain., (© 2025 European Pain Federation ‐ EFIC ®.)

Background: Adolescent chronic pain is a substantial public health problem, and pain symptoms often persist into adulthood. Young adults with chronic pain are at elevated risk for more frequent tobacco, alcohol and cannabis use, and cross-sectional research highlights the importance of psychosocial vulnerability factors. Limited research has examined how adolescent predictors, including mental health symptoms, pain, sleep and family functioning, impact later, young adult substance use., Methods: A prospective cohort of 229 young adults (77.3% female; M age  = 21.0, SD = 1.6) with childhood-onset chronic pain completed measurements in adolescence and a follow-up assessment in young adulthood of past 3-month substance use frequency., Results: Adolescent sleep quality and male sex were associated with more frequent tobacco use; adolescent depression was associated with more frequent alcohol use, and adolescent pain severity was associated with less frequent, and male sex was associated with more frequent cannabis use., Conclusions: Adolescent predictors of young adult substance use among youth with childhood-onset chronic pain represent important factors that may inform assessment, prevention and treatment of substance use in this population. Identifying and testing psychological interventions that target these vulnerability factors may reduce overall substance use risk in young adulthood., Significance: This prospective observational study of young adults with childhood-onset chronic pain identified adolescent depression and sleep quality as vulnerability factors associated with substance use. Given the increasing risk for substance use during adolescence and young adulthood, these findings highlight the potential importance of early intervention to reduce substance use among young adults with childhood-onset chronic pain., (© 2024 European Pain Federation ‐ EFIC ®.)

Background: Methods for identifying high-pain responders undergoing total knee arthroplasty remain important to improve individualized pain management. This study aimed at evaluating pre- and perioperative predictors of pain on Days 2-7 after total knee arthroplasty., Methods: This is a secondary analysis of data from 227 patients participating in two randomized trials. Pain outcomes were mean pain during walking on Days 2-7 and on Days 2, 4 and 7. Multivariable linear and logistic regressions were carried out in two steps. First, only preoperative available variables including demographics, comorbidities, pain catastrophizing scale and preoperative pain were evaluated while controlling for trial intervention and recruitment site. In the second step, perioperative variables and pain during walking 24 h postoperatively were added., Results: The model with only preoperative predictors for mean pain Days 2-7 showed preoperative pain (R-squared 0.097) as the only predictor. In the second model, adding postoperative available variables, only pain 24 h postoperatively (R-squared 0.248) was significant, with a significant main effect of recruitment site. Results for the separate day analysis similarly showed preoperative pain and pain during walking 24 h postoperatively as predictors. The overall best sensitivity (60%) and specificity (74%) for predicting a high-subacute postoperative pain response on Days 2-7 was with cut-off values of VAS 45.5 (out of 100) for pain during walking 24 h postoperatively., Conclusions: Postoperative pain during walking at 24 h is predictive of subacute postoperative pain on Days 2-7 after total knee arthroplasty, while preoperative pain was only a weak predictor., Significance Statement: This study investigated factors associated with pain after total knee arthroplasty beyond the immediate postoperative period. The analysis revealed significant associations between preoperative pain levels and, particularly, pain 24 h postoperatively, with subsequent subacute pain the following week. These findings can assist in identifying patients who would benefit from enhanced, individualized analgesic interventions to facilitate postoperative recovery., (© 2024 European Pain Federation ‐ EFIC ®.)

Objective: Chronic pain is known to be an important construct in clinical practice and a particular form of chronic pain, high-impact chronic pain (HICP), has gained recent interest and attention by pain clinicians, epidemiologists, and clinical researchers. The purpose of our Topical Review is to describe the historical development of measures of HICP and to explore the psychometric properties of HICP as well as to present alternative measurement methods., Methods: We identified strengths and weaknesses of the psychometric characteristics of HICP measures. Limitations of existing HICP measures were discussed and summarized and alternatives to current methods were proposed., Results: HICP operational definitions show variability across studies. All definitions cannot be correct, but which ones are incorrect cannot be determined as there is no gold standard. Random measurement error and recall bias are among the other limitations of current HICP measures. Model-based definitions of HICP, the discrete (for epidemiologic applications) and continuous (for clinical applications) latent variable models are discussed as likely superior alternatives to current methods., Conclusions: Limitations of existing HICP methods are discussed and alternative development approaches to HICP measures are presented. The use of either discrete or continuous latent variable models would improve upon the psychometric characteristics of current HICP evidence. Examples are used to illustrate the benefits of latent variable models over traditional observed variable conceptualizations as the measurement of HICP continues to develop., Significance Statement: This work takes the position that current methods of measuring high impact chronic pain (HICP) likely contain substantial error. We have endorsed an alternative approach for several psychometrically grounded reasons. We recommend that future work consider the discrete latent variable framework for dichotomous measures of HICP and the continuous latent variable framework for continuous measures of HICP. The paper provides illustrative examples of these methods for a different patient reported measure that is lacking a gold standard, much like HICP measures., (© 2024 European Pain Federation ‐ EFIC ®.)

Background: Core stabilisation training is known to be effective in managing pain in patients suffering from chronic low back pain (CLBP). Yet, acute effects of core stabilisation exercise on exercise-induced hypoalgesia (EIH) are largely unknown. This study aimed to examine the EIH effects of an easy-to-perform core stabilisation exercise in CLBP patients and to explore associations between EIH and potential influencing factors (i.e., physical activity, catastrophizing, kinesiophobia, subjective pain state and exercise exertion)., Methods: Thirty patients with unspecific CLBP finished this randomised controlled crossover trial. Patients performed a 10-min isometric core stabilisation exercise and a 10-min control session. Before and after, pain sensitivity was measured via pressure pain thresholds [Newton/cm 2 ] locally (low back; PPT local ) and remotely (forehead, thumb; PPT remote ). Correlation analyses were performed between EIH and influencing factors., Results: A 'Time' × 'Intervention' interaction (p < 0.001) was observed for PPT local with post hoc analysis revealing higher values post exercise (p < 0.001; pre: 56.6 ± 20.6, post: 67.5 ± 26.1). No differences were observed for the control session (p = 0.894; pre: 58.5 ± 24.0, post: 58.4 ± 23.3). No such effect was observed for PPT remote (p = 0.014). Post hoc analyses showed no differences following the exercise session (p = 0.103; pre: 41.3 ± 12.5, post: 42.5 ± 13.6), while lower PPT remote post values were observed post control compared to pre values (p = 0.031; 42.5 ± 14.5, post: 41.3 ± 13.7). The only significant moderate correlation was observed between ΔPPT local of the exercise session and catastrophizing with rho = -0.381., Conclusion: A 10-min isometric core stabilisation exercise results in local lumbar EIH, while no systemic effects are observed. A higher degree of catastrophizing is associated with lower hypoalgesic responses., Significance: This study shows for the first time that a brief and easy-to-perform 10-min core stabilisation exercise produces significant local pain relief (EIH) in patients with unspecific CLBP. The effect is localised to the lumbar region, with no observed impact on remote sites. Higher pain catastrophizing seems to be linked to reduced hypoalgesic response. These findings support the use of short core stabilisation exercises as an effective, immediate, non-pharmacological pain management strategy for these patients., (© 2025 The Author(s). European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation ‐ EFIC ®.)

Background: The management of chronic non-cancer pain (CNCP) is complex. Concerns about adverse effects associated with opioid pain medications and a lack of funding for holistic programs present challenges for decision-making among clinicians and patients. Discrete choice experiments (DCE) are one way of assessing and valuing patient treatment preferences., Method: DCE attributes and levels were generated through qualitative research and included number of medicines, side effects from medicines, pain interference, care management, risk of addiction, activity goals, preferred source of information on pain management and willingness to pay. The survey was administered to participants with CNCP recruited through an existing cohort study (n = 442) and a sample of people living with CNCP recruited through Australia's leading pain advocacy body (Painaustralia) (n = 256)., Results: The median age of participants was 58 years (SD 12.0), the majority were female. The analysis revealed two latent demographic classes: a younger group with higher levels of private health insurance and an older group with lower levels of private health insurance coverage. There were notable differences in preference. The younger cohort exhibited a greater willingness-to-pay to reduce pain interference, whereas the older group prioritized GP management, preferred more medicines and expressed fewer addiction concerns., Conclusion: Patients' treatment preferences diverged based on age and insurance status, underscoring the importance of understanding patient perspectives in treatment communication and care coordination. These findings provide insight into patient decision-making, which is important for promoting access to quality healthcare and engagement with evidence-based treatment of CNCP., Significance Statement: A discrete choice experiment identified two groups: younger, with more private insurance, and older, with less private health insurance, each with unique pain management preferences. Clinicians should be aware that age and private health insurance may have an impact on a patient's preferences for CNCP management., (© 2024 European Pain Federation ‐ EFIC ®.)

Background: Poor acute postoperative pain control, coupled with the use of intravenous medications with a limited and unsafety efficacy spectrum, has led to new therapeutic alternative explorations to reduce adverse events while increasing its analgesic efficacy. There cannabinoids have been proposed as a useful control agent in post-surgical pain. Nevertheless, to date, there is no solid evidence to evaluate them. The current article sought to determine cannabinoids' effectiveness and safety in the aforementioned context., Methods: A systematic review of controlled clinical trials evaluated the efficacy and safety of cannabinoids for the treatment of acute postoperative pain. The study was structured under the Cochrane recommendations. Primary outcomes included: pain intensity reduction, the number and doses of rescue analgesics and adverse events., Results: Of 62 articles found, only five were included. Four of them presented high inter-observer agreement and 60% were classified as having a low risk of bias. When evaluating the objectives of each article, a disparity was found in the investigative methods and terms implemented. Due to the heterogeneity of methods, it was not possible to carry out meta-analytic evaluations and only qualitative evaluations were feasible., Conclusions: Despite finding contradictory evidence in relation to the analgesic cannabis effect in the postoperative context, methodological disparities found in the included articles and the impossibility of performing collective quantitative analyses were more significant. Before concluding with the well-known sentence: "further intervention studies are necessary", this report has identified limitations and has proposed recommendations for the planning and execution of future cannabis clinical trials, which will support new and necessary evidence for stronger meta-analytic reviews., Significance: The management of severe pain after surgery, and the use of intravenous drugs with limited and potentially unsafe effectiveness, has led to the exploration of new treatment options to minimize side effects while improving pain relief. Cannabinoids have been suggested as a potential solution for managing post-surgical pain, but there is currently insufficient evidence to assess their effectiveness. The purpose of this article was to evaluate the effectiveness and safety of cannabinoids in this context., (© 2025 European Pain Federation ‐ EFIC ®.)

Background: Differential target multiplexed spinal cord stimulation (DTM SCS) was shown to be superior to conventional SCS for treating chronic low back pain (CLBP) in subjects with persistent spinal pain syndrome with previous spinal surgery (PSPS-T2) or ineligible for it (PSPS-T1). This study reports 24-month efficacy and safety of DTM SCS vs. conventional medical management (CMM) in PSPS-T1 subjects across four European countries., Methods: This is a prospective, multicenter, open-label, randomized, controlled trial with optional crossover. Subjects randomized 1:1 to DTM SCS or CMM. Primary endpoint was responder rate (% subjects reporting ≥50% CLBP relief) at 6 months. A superiority test compared responder rates between treatments. CLBP and leg pain levels, functional disability, quality of life (QoL), patient satisfaction and global impression of change were evaluated for 24 months. A Composite Responder Index (CRI) was obtained using CLBP relief, disability and QoL. Incidence of study-related adverse events evaluated safety., Results: A total of 55 and 57 subjects were randomized to DTM SCS and CMM respectively. DTM SCS was superior, with CLBP responder rates ≥80% and CLBP relief >5.6 cm (>70% reduction) through the 24-month follow-up. Improvements with DTM SCS in other outcomes were sustained. The CRI was >80% for DTM SCS through 24 months. Opioid medication intake decreased in subjects treated with DTM SCS. Most patients treated with DTM SCS felt satisfied and improved at the end of the study. Safety was congruent with other studies., Conclusion: DTM SCS is efficacious and safe during 24 months for the treatment of CLBP and leg pain in PSPS-T1 patients ineligible for spine surgery., Significance Statement: This randomized controlled trial shows that Differential Target Multiplexed SCS (DTM SCS) is an effective and safe long-term treatment for PSPS type 1 patients suffering from axial low back pain with or without leg pain and who are ineligible for spinal surgery. Currently, CMM treatments are their only option and provide limited benefits. Besides superior pain relief, DTM SCS provides significant improvements in functional disability, quality of life, high levels of satisfaction and perceived impression of change., (© 2024 The Author(s). European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation ‐ EFIC ®.)

Background: In Europe, opioid use has surged, largely due to prescriptions for chronic non-malignant pain (CNMP). General practitioners (GPs) and community pharmacists (CPs) play a major role in opioid prescribing for non-malignant pain. Exploring their personal beliefs and practices might reveal underlying mechanisms to identify measures that could halt the further escalation of opioid use., Methods: Guided by the health belief model, a survey was designed and distributed nationwide to examine the practices and beliefs of GPs and CPs in the domains: threats, benefits, barriers and self-efficacy. The results of GPs and CPs were compared at the statement level using chi-square analysis., Results: Of 214 GPs and 212 CPs who completed the survey, the majority agreed that too many opioids are used in the treatment of chronic non-malignant pain (66.8% GPs and 66.5% CPs). Furthermore, they were concerned about the addictive potential of opioids (83.1% GPs and 71.7% CPs). In general, both professions have concerns about opioid use. GPs report a slightly higher degree of self-efficacy and perceive fewer benefits from opioids in treating CNMP. GPs and CPs valued the recommended measures to reduce opioid prescribing, yet less than half actively implement these strategies in their clinics., Conclusion: GPs and CPs believe that opioids are being used too frequently to treat CNMP. However, both professions lack the actions to improve opioid-related care. GPs and CPs require education, collaboration and tools to implement guidelines on non-malignant pain and opioids., Significance: This study, guided by the health belief model, reveals that general practitioners and community pharmacists have serious concerns about opioid use in chronic non-malignant pain. Despite shared concerns, both professions differ in their beliefs about opioid benefits and perceived self-efficacy. Both professions have in common that they value recommended measures to reduce opioid prescribing. Also, they both struggle to implement strategies, emphasizing the urgent need for education, collaboration and tools to align practices with guidelines on non-malignant pain and opioids., (© 2024 The Author(s). European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation ‐ EFIC ®.)

Background: Commonly used models for eliciting muscle pain involve the injection of algesic substances or the induction of delayed onset muscle soreness. The former require invasive procedures, and the time frame for pain induction and subsidence in the latter can be inconvenient. This study presents a detailed spatiotemporal characterization of a new experimental model of muscle pain based on short-wave diathermy (SWD), developed to overcome the limitations of existing models., Methods: The shoulder was selected as target site and the effects of the model were tested in two sessions to assess its reliability. Pain intensity profiles were recorded during the application of SWD, and changes in pressure pain threshold (PPT) in the infraspinatus muscle, together with pain intensity, duration, and quality were assessed 30 min after induction., Results: SWD-induced pain intensity scores averaged 4 points on a visual analogue scale, whereas PPT showed a consistent decrease of about 25% relative to baseline values. Pain was localized in the shoulder area, and was described as continuous, dull, well-delimited, heavy, and bearable. Pain lasted for an average of 145 min without requiring reinduction and was reliably elicited in both experimental sessions., Conclusion: SWD can be used to elicit experimental muscle pain in a non-invasive, long-lasting, and reliable way and allows for repeated within- and between-session testing in the shoulder., Significance Statement: SWD produces deep heating in muscles by converting electromagnetic energy to thermal energy. It was previously shown that it can be used to elicit experimental pain in the forearm muscles, and the present study demonstrates that this can be reliably generalized to other body sites, such as the shoulder. Furthermore, SWD application is non-invasive and presents a convenient time frame for pain induction and subsidence, thus overcoming limitations associated with traditional muscle pain models., (© 2024 The Author(s). European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation ‐ EFIC ®.)

Introduction: Biopsychosocial approach in patients suffering chronic low back pain (CLBP) promotes pain self-management strategies. Current evidence recommends high dose of Pain Neuroscience Education (PNE) for clinically significant differences. However, the workload and time constraints experienced by healthcare providers impede the application of the recommended treatment regimen. In fact, Back School with a biomechanical model is the main approach to manage CLBP in public systems., Objective: The objective of this study is to explore the effect of a 60 min single session of PNE as an adjunct to back school on pain intensity and psychological variables patients with CLBP., Methods: A double-blind, two-arm randomized controlled clinical trial was conducted in patients with CLBP who attended back school sessions held in a Spanish public hospital. A total of 121 patients were randomized into control group, who received the Back School program during 5 weeks, and intervention group, who additionally received a single session of PNE. Patient-reported outcomes were the Numerical Pain Rating Scale, Central Sensitization Inventory, Pain Catastrophizing Scale, and Tampa Scale of Kinesiophobia, with a 12-week follow-up., Results: A total of 113 patients were analysed. Intervention and control group presented similar effects on pain and kinesiophobia. At follow-up, intervention group exhibited reduced sensitization and catastrophism scores compared with control, including the subscales. Additionally, PNE reduced the percentage of participants classified as having central sensitization compared with control., Conclusions: Adding a single PNE session in the back school program did not reduce pain but improved psychological factors as central sensitization and pain catastrophizing at medium-term. This study highlights the potential of PNE to optimize treatment strategies for CLBP, especially in public health centres where time resources are scarce., Significance Statement: Adding a single PNE session in the back school program did not reduce pain but improved psychological factors as central sensitization and pain catastrophism at medium-term., (© 2024 European Pain Federation ‐ EFIC ®.)

Background: Chronic pain is associated with depression and anxiety symptoms. Pain management programms, delivered face-to-face or via the internet, can effectively help adults manage the impacts of chronic pain. Sudden gains are defined as substantial, rapid, and lasting symptom reductions that occur between consecutive treatment sessions and have been associated with better treatment outcomes in non-pain samples. This study examined whether adults with chronic pain report sudden gains in depression or anxiety symptoms during an 8-week online pain management programme, and whether sudden gains were associated with better treatment outcomes for depression or anxiety. Dominant theories of sudden gains argue that therapists are required for sudden gains to be maintained and improve treatment outcomes., Methods: Using data from a published randomized controlled trial (n = 338), sudden gains and treatment outcomes were compared across three levels of therapist guidance provided alongside the programme: weekly, optional, and self-guided., Results: Similar rates of sudden gains were observed in depression (22%) and anxiety (24%) across the treatment period, and most sudden gains occurred between Weeks 1 and 2 of treatment. Therapist guidance was not associated with sudden gains; higher baseline symptom severity emerged as the only consistent predictor of sudden gain status. No significant differences in treatment outcomes for depression or anxiety symptoms between sudden gainers and non-gainers were observed across therapist guidance conditions., Conclusions: These results do not support an association between sudden gains in depression or anxiety symptoms and better post-treatment outcomes, at least for adults with chronic pain., Significance Statement: Sudden gains in depression and anxiety symptoms were not associated with improved treatment outcomes for adults with chronic pain who participated in an online pain management programme, regardless of the level of therapist guidance provided. These findings suggest possible differences in symptom change in chronic pain samples compared to general population samples., (© 2024 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation ‐ EFIC ®.)

Background: Acute physical activity leads to exercise-induced hypoalgesia (EIH). However, to what degree it can be induced by very short but highly intensive exercise is largely unknown. This study aims to investigate the effects of two different short all-out isokinetic exercise sessions on EIH., Methods: Twenty young male participants underwent three different interventions (90, 15 s all-out isokinetic cycling, respectively, and control) after an individualized low-intensity warm-up in a randomized-controlled-crossover design. Before (pre), after warm-up (post 1) as well as immediately post-intervention (post 2) pain sensitivity was measured employing pressure pain thresholds (PPT; in N) at the elbow, knee and ankle joints as well as the sternum and forehead. Performance parameters (e.g. lactate, perceived exertion, heart rate) were documented., Results: A 'time' × 'intervention' × 'body site' interaction effect (p < 0.001, η 2 partial = 0.110) was observed for PPT. Both isokinetic interventions resulted in EIH at all body sites, even after ruling out any warm-up effects, while effects were larger for 90 s (maximum increase of 25.7 ± 11.7 N) compared to 15 s (maximum increase of 19.3 ± 18.9 N), and control (maximum increase of 8.0 ± 6.1 N). Compared to control, 15 s also resulted in hypoalgesic effects and differences were not observed at all sites. In this study, 90 s resulted in higher lactate, subjective exhaustion and heart rate levels compared to 15 s and control (p < 0.001), while higher values were also observed for 15 s compared to control., Conclusion: Global EIH assessed immediately after exercise can be induced by short highly intensive exercises. The effects are greater when the subjective and the objective exertion are higher as induced by the 90 s intervention., Significance Statement: This study investigates the potential for brief, highly intensive exercise sessions to induce exercise-induced hypoalgesia (EIH). The research demonstrates that EIH can indeed be triggered by such short workouts, with greater effects observed during a 90 s session compared to a 15 s one, most likely due to higher subjective and objective exertion. These findings offer insights into the potential for extremely brief but intense exercises to alleviate pain, impacting exercise recommendations and pain management strategies., (© 2024 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation ‐ EFIC ®.)

Background: Vagal activity has analgesic effects that are attributed to exercise-induced hypoalgesia (EIH). High vagal tone and low pain sensitivity are reported in individuals who routinely exercise yet, their association is unclear. Furthermore, it is unknown if the heightened vagal tone following high physical activity predicts and intensifies EIH., Methods: Fifty-one healthy participants (27 low-moderately physically active; 27 females) underwent a resting-state electrocardiogram followed by heart rate variability analysis. Pain measurements, including pressure (PPT) and heat (HPT) pain thresholds, ratings of tonic heat pain (THP) and conditioned pain modulation (CPM) paradigm, were conducted pre- and post-exercise on a cycle ergometer., Results: The highly active group demonstrated higher vagal tone compared to the low-moderately active (root mean square of successive differences between R-R intervals: 63.96.92 vs. 34.78 ms, p = 0.018; percentage of successive R-R intervals that exceed 50 ms: 24.41 vs. 11.52%, p = 0.012). Based on repeated-measure ANOVA, the highly active group showed higher PPT at pre-exercise, compared to the low-moderately active group (382 kPa vs. 327 kPa; p = 0.007). Post-exercise, both groups demonstrated EIH, increased HPT (p = 0.013) and decreased THP ratings (p < 0.001). Linear regression revealed that only in the low-moderately active group, higher vagal tone was associated with more efficient pre-exercise CPM and a greater reduction in THP ratings post-exercise (p ≤ 0.01)., Conclusions: Highly active individuals demonstrate greater vagal tone and lower pain sensitivity but no greater EIH. Vagal tone moderates pain inhibition efficiency and EIH only in low-moderately active individuals. These findings suggest that physical activity level moderates the vagal-pain association via the endogenous analgesia system., Significance: Highly physically active individuals exhibit greater vagal tone and reduced sensitivity to experimental pain, yet they do not benefit more from exercise-induced hypoalgesia (EIH) compared to low-moderately active individuals. Moreover, low-moderately active individuals with greater vagal tone exhibited more efficient endogenous pain inhibition and greater EIH, suggestive of the moderation effect of physical activity level on vagal-pain associations., (© 2024 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation ‐ EFIC ®.)

Background: Persistent postsurgical pain (PPSP) after lung cancer surgery is common and current definitions are based on evaluations at a single time point after surgery. Pain intensity and symptoms may however fluctuate and change over time, and be impacted by multiple and shifting factors. Studies of postoperative recovery patterns and transition from acute to chronic pain are needed for further investigation of preventive measures and treatments to modify unfavourable recovery paths., Methods: In this explorative study, 85 patients undergoing surgery due to either presumptive or confirmed lung cancer reported pain intensities bi-monthly for 12 months. Pain trajectories during recovery were investigated, using group-based trajectory modelling. Associations with possible risk factors for PPSP, including clinical variables and anxiety and depression score (HADS), were also explored., Results: A trajectory model containing three 12-month pain recovery groups was computed. One group without PPSP fully recovered (50%) within two to three months. Another group with mild-intensity PPSP followed a protracted recovery trajectory (37%), while incomplete recovery was observed in the last group (13%). Acute postoperative pain and younger age were associated with a less favourable recovery trajectory. More neuropathic pain symptoms were observed in patients with incomplete recovery., Conclusions: Three clinically relevant recovery trajectories were identified, based on comprehensive pain tracking. Higher acute postoperative pain intensity was associated with an unfavourable pain recovery trajectory., Significance Statement: Understanding the transition from acute to chronic postoperative pain and identifying preoperative risk factors is essential for the development of targeted treatments and the implementation of preventive measures. This study (1) identified distinct recovery trajectories based on frequent pain assessment follow-ups for 12 months after surgery and (2) evaluated risk factors for unfavourable postoperative pain recovery paths. Findings suggest that early higher postoperative pain intensity is associated with an unfavourable long-term recovery path., (© 2024 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation ‐ EFIC ®.)

Background: Total knee replacement (TKR) is the gold standard treatment for end-stage chronic osteoarthritis pain, yet many patients report chronic postoperative pain after TKR. The search for preoperative predictors for chronic postoperative pain following TKR has been studied with inconsistent findings., Methods: This study investigates the predictive value of quantitative sensory testing (QST) and PainDETECT for postoperative pain 3, 6 and 12 months post-TKR. We assessed preoperative and postoperative (3 and 6 months) QST measures in 77 patients with knee OA (KOA) and 41 healthy controls, along with neuropathic pain scores in patients (PainDETECT). QST parameters included pressure pain pressure threshold (PPT), pain tolerance threshold (PTT), conditioned pain modulation (CPM) and temporal summation (TS) using cuff algometry, alongside mechanical hyperalgesia and temporal summation to repeated pinprick stimulation., Results: Compared to healthy controls, KOA patients at baseline demonstrated hyperalgesia to pinprick stimulation at the medial knee undergoing TKR, and cuff pressure at the calf. Lower cuff algometry PTT and mechanical pinprick hyperalgesia were associated with preoperative KOA pain intensity. Moreover, preoperative pinprick pain hyperalgesia explained 25% of variance in pain intensity 12 months post-TKR and preoperative neuropathic pain scores also captured 30% and 20% of the variance in postoperative pain at 6 and 12 months respectively. A decrease in mechanical pinprick hyperalgesia from before surgery to 3 months after TKR was associated with lower postoperative pain at the 12 months post-TKR follow-up., Conclusion: Our findings suggest that preoperative pinprick hyperalgesia and neuropathic-like pain symptoms show predictive value for the development of chronic post-TKR pain., Significance Statement: This study's findings hold significant implications for chronic pain management in knee osteoarthritis patients, particularly those undergoing total knee replacement surgery (TKR). Mechanical hyperalgesia and neuropathic pain-like characteristics predict postoperative pain 1 year after TKR, emphasizing the importance of understanding pain phenotypes in OA for selecting appropriate pain management strategies. The normalization of hyperalgesia after surgery correlates with better long-term outcomes, further highlighting the therapeutic potential of addressing abnormal pain processing mechanisms pre- and post-TKR., (© 2024 The Author(s). European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation ‐ EFIC ®.)

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., (© 2024 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation ‐ EFIC ®.)

Background: Thoracic epidural analgesia (TEA) and intravenous patient-controlled analgesia (IV-PCA) are widely used to mitigate immediate postoperative pain; however, their effects on long-term disability-free survival are poorly documented. This study aimed to compare the effects of postoperative TEA and IV-PCA on disability-free survival in patients who underwent thoracic or abdominal surgery., Methods: This post hoc analysis of a prospective observational study included 845 inpatients aged ≥55 years that underwent elective thoracic and abdominal surgery between 1 April 2016 and 28 December 2018 in a tertiary care hospital. Inverse probability of treatment weighted (IPTW) using stabilized inverse propensity scores was adopted to minimize bias. The primary outcome in this study was disability-free survival, defined as survival with a 12-item World Health Organization Disability Assessment Schedule 2.0 score of <16%, assessed at 3 months and 1 year after surgery., Results: The final analysis included 601 patients who received TEA and 244 who received IV-PCA. After IPTW, the weighted incidence of disability-free survival at 3 months and 1 year was 60.5% and 61.4% in the TEA group and 78.3% and 66.2% in the IV-PCA group, respectively. The adjusted OR for disability-free survival at 3 months and 1 year was 0.84 (95% confidence interval [CI]: 0.50-1.39) and 1.21 (95% CI: 0.72-2.05), respectively, for the TEA group., Conclusion: No significant differences were observed in the disability-free survival at 3 months and 1 year after elective thoracic and abdominal surgery in patients aged ≥55 years who received TEA or IV-PCA., Significance Statement: This study is the first in our setting to document the long-term effects of patient-controlled analgesia. In a post hoc analysis of our prospective cohort study, we show that although differences in chronic postsurgical pain exist at 3 months post-surgery, disability-free survival rates at 1 year do not differ irrespective of the choice of patient-controlled analgesia. The findings of this study highlight the need for shared decision-making between clinicians and patients., (© 2024 European Pain Federation ‐ EFIC ®.)

Background and Objective: The relationship between chronic daily headache (CDH), depression symptoms, and brain volume remains unclear., Methods: To investigate the effects of CDH on brain volume and the impact of depressive symptoms (DSs) as well as the effects of demography and medication overuse, PubMed, Embase, and Web of Science databases were systematically searched using appropriate keyword strings to retrieve observational studies from inception to May 2023., Results: Two distinct comparisons were made in CDH patients: (1) those with DSs versus their pain-free counterparts and (2) those without DSs versus pain-free controls. The first comprised nine studies enrolling 225 CDH patients with DSs and 234 controls. Beck depression inventory, Hamilton depression scale, and Hospital anxiety/depression scale were used to assess DSs, revealing significantly more DSs in CDH patients with DSs compared to their controls (all p < 0.05). Besides, the second analysed four studies involving 117 CDH patients without DSs and 155 comparators. Compared to CDH patients without DSs, those with DSs had a smaller brain volume than controls (p = 0.03). Furthermore, CDH patients with DSs who did not overuse medications showed a smaller right cerebral cortical volume than overusers (p = 0.003). A significant inverse correlation between female prevalence and brain volume (p = 0.02) was revealed using regression analysis., Conclusions: Pain-induced persistent depressive symptoms not only incur structural alterations but also encompass affective-motivational changes, involving medication use and gender-specific health concerns., Significance: This study highlighted the importance of an integrated CDH treatment, emphasizing psychological interventions for the affective-motivational component alongside pain management., (© 2024 European Pain Federation ‐ EFIC ®.)

Background: Women are more likely to experience multiple overlapping pain conditions (MOPCs) relative to men. Post-traumatic stress disorder can negatively impact the severity and trajectory of chronic pain and its treatment. Specific associations between gender, post-traumatic stress disorder (PTSD), and MOPCs require further examination., Methods: A cohort of all Veterans in 2021 who met criteria for one or more of 12 chronic pain types was created using national Veterans Health Administration administrative data. MOPCs were defined as the number of pain types for which each patient met criteria. Multivariable logistic regression models estimated gender differences in frequency for each of the 12 pain subtypes, after controlling for demographics and comorbidities. Negative binomial regression was used to estimate gender differences in the count of MOPCs and to explore moderation effects between gender and PTSD., Results: The cohort included 1,936,859 Veterans with chronic pain in 2021, which included 12.5% women. Among those with chronic pain, women Veterans had higher rates of MOPCs (mean = 2.3) relative to men (mean = 1.9): aIRR = 1.31, 95% CI: 1.30-1.32. PTSD also served as an independent risk factor for MOPCs in adjusted analysis (aIRR = 1.23, 95% CI: 1.23-1.24). The interaction term between gender and PTSD was not significant (p = 0.87). Independent of PTSD, depressive disorders also served as a strong risk factor for MOPCs (aIRR = 1.37, 95% CI: 1.36-1.37)., Conclusions: Individuals with MOPCs and PTSD may have complex treatment needs. They may benefit from highly coordinated trauma-sensitive care and integrated interventions that simultaneously address pain and PTSD., Significance: Women were significantly more likely than men to experience MOPCs. PTSD was also significantly, independently, associated with MOPCs. Patients, particularly women, may benefit from tailored interventions that address both trauma and MOPCs., (© 2024 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation ‐ EFIC ®. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)

Background and Objective: The development, evaluation and implementation of digital self-management interventions for chronic pain have increased exponentially. While intervention outcomes appear promising to improve well-being and functioning in target populations, it is unclear how the development and evaluation processes were structured and how implementation was planned and executed. The aim of this systematic review is to provide a comprehensive overview of implementation frameworks used to guide and evaluate scientific innovation in chronic pain., Databases and Data Treatment: Four bibliography databases (Medline, Web of Science, PsycInfo, CINAHL) and two registries (PubMed Central, MedaRxiv) were systematically searched. Hits (n = 6830) and full texts (n = 351) were screened and read by two independent reviewers. Peer-reviewed articles that met the inclusion criteria were included in the narrative synthesis., Results: In total, 10 studies were identified that report on seven distinct interventions. Five implementation frameworks were utilized across these studies: Behavioural Interventions using Technology (BIT); Consolidated Framework for Implementation Research (CFIR); mHealth Agile and User-Centered Research and Development Lifecycle; Medical Research Council (MRC); Reach, Effectiveness, Adoption Implementation, and Maintenance (RE-AIM). Frameworks were operationalized using qualitative and quantitative methods, evaluating the innovation on various levels (e.g., individual vs. organizational) and applying a variety of study designs (e.g., single-arm or large trials)., Conclusions: By utilizing implementation frameworks, access to evidence-based chronic pain care may be increased. Although the evidence on the utility of implementation frameworks to guide and evaluate digital self-management interventions is still limited, the body of literature is increasing. Future studies are urged to operationalize, communicate and discuss the innovation process, to promote transparency and replicability., Significance: The use of implementation frameworks to guide and evaluate digital self-management interventions for chronic pain is a recent development in the field. Several promising examples exist and are presented in this review. Currently, the evidence is still limited, and prospective studies need to transparently operationalize, communicate and discuss their efforts. By utilizing an implementation framework, promising interventions can be made available to end-users, closing the research-to-clinical practice gap and increasing access to evidence-based care to people with chronic pain., (© 2024 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation ‐ EFIC ®.)

Context: The prevalence of persistent pain among breast cancer survivors (BCS) is high, and it is unclear what distinguishes those with persistent pain from those without. Research suggests that differences in somatosensory function evaluated by quantitative sensory testing (QST) may be responsible., Objectives: This study aimed to describe somatosensory profiles in terms of hyper- and hypoesthesia in BCS with and without persistent pain using reference data from healthy controls. Second, QST parameters of BCS with and without pain were compared with those of healthy controls (i.e., a negative control group) and patients with fibromyalgia (i.e., a positive control group)., Methods: Participants (n = 128) were divided into four equal groups: healthy controls, BCS with persistent pain, BCS without persistent pain, and patients with fibromyalgia. Nine QST parameters were evaluated at the trunk and at a remote location. Somatosensory profiles were determined by Z-score transformation of QST data using normative data from healthy controls., Results: At the trunk, compared to healthy controls, BCS with persistent pain exhibited sensory aberrations across five out of seven QST parameters: pressure pain threshold, mechanical detection, and thermal thresholds. Pain-free BCS showed similar sensory aberrations across the four QST parameters compared to healthy controls: mechanical detection and thermal thresholds. Temporal summation and conditioned pain modulation were not significantly different between groups., Conclusion: BCS with persistent pain exert aberrations in peripheral processing of nociceptive signals, heightened facilitation of nociceptive signals, and higher psychosocial burden when compared to pain-free BCS, healthy controls, and patients with fibromyalgia., Significance: This study investigates the somatosensory function of breast cancer survivors with and without persistent pain using quantitative sensory testing and two control group (i.e., patients with fibromyalgia and healthy controls). Our results indicate somatosensory aberrations within the peripheral, but not central pathways in breast cancer survivors with persistent pain. Our findings contribute to a better understanding of the somatosensory mechanisms underlying persistent pain, which may inform future interventions to prevent the development of persistent pain, and improve treatment modalities., (© 2024 European Pain Federation ‐ EFIC ®.)

Background: Centres dedicated to chronic postsurgical pain (CPSP) have been developed, but delays for accessing to it are generally long. Teleconsultation might be a means to facilitate access to care by allowing an initial triage. CPSPs are neuropathic pain in around half of the cases and their diagnosis is mainly based on the score obtained from validated questionnaires. Among them, those requiring a neurological examination (i.e. the Douleur Neuropathique en 4 questions [DN4]) have a better sensitivity and specificity, and should be preferred. However, effectiveness of a remote neurological examination remains to be established. The aim of this observational study is to check during a face-to-face consultation if, after a short training, a naïve patient is capable to self-assess the clinical signs of neuropathic sensations., Methods: Thirty patients with suspected neuropathic pain were seen in a face-to-face postoperative pain consultation. Before examination, the patient was instructed to fill the DN4 questionnaire, including the neurological examination. Once explanations were given and checked, the patient was left and completed it alone. Then, the pain physician performed the DN4 questionnaire. Inter-rater reliability between patient and pain physician was assessed for each item and for DN4 score with the Kappa coefficient., Results: For each item of the DN4 questionnaire, Kappa coefficients were between 0.74 and 1, and could be considered as excellent. For DN4 ≥ 4, the Kappa coefficient was 0.86., Conclusions: Our results suggest that after a short training, a naïve patient is capable of recognizing and diagnosing symptoms of neuropathic pain., Significance: Our results suggest that self-assessment, carried out after brief training and using a simple tool, provides results comparable to those obtained by a specialist physician to diagnose symptoms of neuropathic pain. If the results of the current study are confirmed on a larger scale, self-assessment will help improve access to specialized chronic pain care by better orienting patients and opening up access to teleconsultations., (© 2024 European Pain Federation ‐ EFIC ®.)

Background: Guidelines recommend opioid deprescribing in patients on long-term opioid treatment for chronic non-cancer pain. This study aims to explore facilitators and barriers in opioid deprescribing among general practitioners in the Netherlands. In addition, this study aims to identify possibilities for improvement regarding opioid deprescribing in primary care., Methods: Focus group discussions with Dutch General practitioners were held by two skilled moderators. The focus group discussions were transcribed verbatim and analysed using MAXQDA software. Three independent reviewers searched for overarching themes using thematic analysis with an inductive approach. Discussions were organized until data saturation was reached., Results: Twenty-two general practitioners participated in four focus group discussions. Five main themes emerged from the data: (1) patient-centred care; (2) ensuring proper pain management (3) dilemmas and hardships in dealing with opioid use disorder; (4) the competency gap; (5) needs and possibilities to improve opioid deprescribing in primary care. The first theme addresses the main facilitators in opioid tapering. The following three themes emerged as main barriers in opioid deprescribing. The fifth theme identified possibilities for change., Conclusions: This study indicates the importance of intrinsic motivation and a tailored approach to deprescribe opioids in patients with chronic pain on long-term opioid treatment. Identified barriers include struggles in pain management, challenges caused by opioid use disorder, insufficient capacities such as time constraints and lack of skills. Recommendations for improvement involve enhanced collaboration with healthcare professionals in primary and secondary care, provision of practical tools and assurance of sufficient time., Significance: This focus group study among 22 Dutch general practitioners elucidates the complexities of opioid deprescribing and reveals pivotal themes such as patient-centred care, pain management challenges, and competency gaps. The findings underscore the crucial role of intrinsic motivation and that of a tailored approach in opioid deprescribing, while demonstrating how a lack in effective pain treatments, practical capacities and challenges caused by opioid dependence, impede opioid deprescribing. By uncovering these complexities, this study aims to inform future deprescribing strategies., (© 2024 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation ‐ EFIC ®.)

Background: Chronic postoperative pain after total knee replacement (TKR) is a major clinical problem. It is still unclear if specific inflammatory mediators are associated with long-term postoperative pain complications. The current exploratory study aimed to (1) evaluate a multiplex of inflammatory mediators 5 years after TKR surgery in patients with different degrees of postoperative pain intensities and (2) study any association of the markers with clinical pain intensity, cognitive and functional outcomes., Methods: Plasma samples were collected 5 years after TKR surgery from 76 knee patients (43 females; 33 males) and analysed for 44 inflammatory markers. Pain (using visual analogue scale, VAS), the pain catastrophizing scale (PCS) and the Oxford knee score (OKS) were evaluated. Patients were categorized as high or low groups based on VAS, PCS and OKS scores. Associations between inflammatory markers, VAS, PCS and OKS were analysed and the marker expressions were compared between groups., Results: Pearson's correlations found 12 biomarkers associated with VAS (p < 0.05), 4 biomarkers with PCS and 3 biomarkers with OKS (p < 0.05). Four markers were altered in patients suffering from high compared to low chronic postoperative pain, three markers were altered in high compared to low catastrophizers and three markers were altered in patients with poor functional scores (p < 0.05)., Conclusions: The present exploratory study suggests that low-grade inflammation might be present in a subset of patients with high pain, high catastrophizing and low function 5 years after TKR. These exploratory results provide insights into some of the long-term postoperative complications after TKR surgery., Significance Statement: This exploratory study evaluated a subset of inflammatory markers and the association to clinical pain intensity, knee function and pain catastrophizing in patients 5 years after total knee replacement surgery. Our results provide insights into the understanding of the underlying mechanisms that may drive the long experience of pain after TKR surgery., (© 2024 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation ‐ EFIC ®.)

Background: The negative consequences of prescription opioid misuse and opioid use disorder make it relevant to identify factors associated with this problem in individuals with chronic pain. This cross-sectional study aimed at identifying subgroups of people with chronic pain based on their psychological profiles, prescription opioid misuse, craving, and withdrawal., Methods: The sample comprised 185 individuals with chronic pain. We performed hierarchical cluster analysis on impulsivity, anxiety sensitivity, pain acceptance, pain intensity, opioid misuse, craving, and withdrawal., Results: The four-cluster solution was the optimal one. Misuse, craving, and anxiety sensitivity were higher among people in the Severe-problems cluster than among people in the other three clusters. Withdrawal was the highest in the High-withdrawal cluster. Impulsivity was higher among people in the Severe-problems and High-withdrawal clusters than those in the Moderate-problems and Mild-problems clusters. Pain acceptance was higher among people in the Mild-problems cluster than among people in the other three clusters. Anxiety sensitivity and misuse were higher among people in the Moderate-problems cluster than among people in the Mild-problems cluster., Conclusions: These results support that impulsivity, anxiety sensitivity, and pain acceptance are useful constructs to identify subgroups of people with chronic pain according to their level of prescription opioid misuse, craving, and withdrawal. The results of this study may help in selecting the early intervention most suitable for each of the identified profiles., Significance: The psychological profile of individuals with chronic pain, prescription opioid misuse, craving, and withdrawal is characterized by fearing anxiety-related symptoms due to the catastrophic interpretation of such symptoms and reacting impulsively to negative moods. In contrast, participants with high pain acceptance had less prescription opioid misuse, craving, and withdrawal. The profiles identified in this study could help clinicians select targets for intervention among profiles with similar needs and facilitate early interventions to prevent opioid misuse onset or aggravation., (© 2024 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation ‐ EFIC ®.)

Background: Chronic pain is a condition with severe impact on many aspects of life, including work, functional ability and quality of life, thereby reducing physical, mental and social well-being. Despite the high prevalence and burden of chronic pain, it has received disproportionally little attention in research and public policy and the societal costs of chronic pain remain largely unknown. This study aimed to describe the long-term healthcare and work absence costs of individuals with and without self-identified chronic pain., Methods: The study population were participants in two Norwegian population health studies (HUNT3 and Tromsø6). Participants were defined as having chronic pain based on a self-reported answer to a question on chronic pain in the health studies in 2008. Individuals in the study population were linked to four national register databases on healthcare resource use and work absence., Results: In our study, 36% (n = 63,782) self-reported to have chronic pain and the average years of age was 56.6. The accumulated difference in costs between those with and without chronic pain from 2010 to 2016 was €55,003 (CI: 54,414-55,592) per individual. Extrapolating this to the entire population suggests that chronic pain imposes a yearly burden of 4% of GDP. Eighty per cent of the costs were estimated to be productivity loss., Conclusion: Insights from this study can provide a greater understanding of the extent of healthcare use and productivity loss by those with chronic pain and serve as an important basis for improvements in rehabilitation and quality of care, and the education of the public on the burden of chronic pain., Significance: This was the first study to estimate the economic burden associated with chronic pain in the general population using linked individual-level administrative data and self-reported survey answers. We provide calculations showing that annual costs of chronic pain may be as high as €12 billion or 4% of GDP. Findings from this study highlight the need for a greater understanding of the substantial healthcare use and productivity losses among individuals with chronic pain., (© 2024 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation ‐ EFIC ®.)

Background and Objective: Contextual effects (e.g. patient expectations) may play a role in treatment effectiveness. This study aimed to estimate the magnitude of contextual effects for conservative, non-pharmacological interventions for musculoskeletal pain conditions. A systematic review and meta-analysis of randomized controlled trials (RCTs) that compared placebo conservative non-pharmacological interventions to no treatment for musculoskeletal pain. The outcomes assessed included pain intensity, physical functioning, health-related quality of life, global rating of change, depression, anxiety and sleep at immediate, short-, medium- and/or long-term follow-up., Databases and Data Treatment: MEDLINE, EMBASE, CINAHL, Web of Science Core Collection, CENTRAL and SPORTDiscus were searched from inception to September 2021. Trial registry searches, backward and forward citation tracking and searches for prior systematic reviews were completed. The Cochrane risk of bias 2 tool was implemented., Results: The study included 64 RCTs (N = 4314) out of 8898 records. For pain intensity, a mean difference of (MD: -5.32, 95% confidence interval (CI): -7.20, -3.44, N = 57 studies with 74 outcomes, GRADE: very low) was estimated for placebo interventions. A small effect in favour of the placebo interventions for physical function was estimated (SMD: -0.22, 95% CI: -0.35, -0.09; N = 37 with 48 outcomes, GRADE: very low). Similar results were found for a broad range of patient-reported outcomes. Meta-regression analyses did not explain heterogeneity among analyses., Conclusion: The study found that the contextual effect of non-pharmacological conservative interventions for musculoskeletal conditions is likely to be small. However, given the known effect sizes of recommended evidence-based treatments for musculoskeletal conditions, it may still contribute an important component., Significance: Contextual effects of non-pharmacological conservative interventions for musculoskeletal conditions are likely to be small for a broad range of patient-reported outcomes (pain intensity, physical function, quality of life, global rating of change and depression). Contextual effects are unlikely, in isolation, to offer much clinical care. But these factors do have relevance in an overall treatment context as they provide almost 30% of the minimally clinically important difference., (© 2023 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation ‐ EFIC ®.)

Background: The aims of this bibliometric analysis were (1) a longitudinal analysis of the publication landscape in the field of pain (1975-2020) and (2) to characterize the overall publication profiles for two selected journals: European Journal of Pain and PAIN® utilizing an automated approach., Methods: Database searches in Scopus extracted all journals with 'pain' in their title. For the two specific journals, papers were manually/automatically profiled into preclinical, human and translational studies., Results: A gross list of 64 journals in the field of pain consisting of both active and ceased journals in Scopus were included in this analysis which identified 62,565 papers with approximately 4000 papers published/year. These papers include 2759 and 9156 papers in Eur. J. Pain and PAIN®, respectively. Currently, there are 24 active 'pain' journals. Authors/paper increase from 2 to 7 indicating a development from mono-disciplinary to multi-disciplinary studies. The overall publication profiles assessing preclinical, human (experimental/clinical) and translational papers in Eur. J. Pain and PAIN® were almost similar (14%, 75% and 10% versus 26%, 63% and 10%). Papers have changed over the years from mono-disciplinary studies (e.g. behavioural studies) to multi-disciplinary studies (e.g. combined behavioural and cell studies). After optimization, the search model matched the manual screening by 100%, 98% and 96% for the preclinical, clinical and healthy volunteer categories., Conclusions: Over the last 45 years, more than 60,000 pain-related papers have been published. Papers develop over the years from mono-disciplinary to multi-disciplinary studies. The overall publication profile including preclinical, human (experimental/clinical) and translational papers was almost similar in Eur. J. Pain and PAIN®., Significance: The bibliometric analysis of a pain journal provides information on which specific areas of research are published, how this may have changed over the years and how a journal is positioned compared with other journals in the field., (© 2023 European Pain Federation ‐ EFIC ®.)

Background: Neck pain is common among individuals with migraine, but there is a lack of information of how this comorbidity can be associated with cervical muscle function. This controlled cross-sectional study aimed to compare cervical muscle function, activity, and sensitization in women with migraine, neck pain, both, and neither., Methods: This study included women, between 18 and 55 years old, with either episodic migraine with or without aura, without any concomitant headache diagnosis; chronic neck pain, with at least moderate intensity and mild disability; or neither headache nor neck pain. Pain pressure threshold, allodynia, muscle strength, and endurance and cervical muscles activity were evaluated., Results: One hundred subjects, with mean age of 30.4 years old, were stratified by diagnosis (n = 25 per group) and by self-reported pain during tests. Lower endurance during flexion was observed for migraine and neck pain (34s) relative to neck pain alone (45s), migraine (40s), and controls (58s) (p = 0.04). For extensor endurance, means were 142s, 166s, 215s, and 270s, respectively (p < 0.001). Endurance times were impacted by the presence of test-induced pain decreasing about 40%-53% of the performance. Diagnostic groups did not differ significantly in strength (p > 0.05), but all pain groups presented significantly higher proportion of test-induced pain, lower muscle activity during the maximal isometric voluntary contractions, and lower pressure pain thresholds., Conclusion: Patients with migraine, chronic neck pain, and the association of both present altered cervical muscle function and activity. Also, test-induced pain impacts significantly on neck muscles endurance., Significance: The diagnosis of migraine and chronic neck pain is associated with altered function and activity of the cervical muscles. However, the test-induced pain had an important contribution to worse cervical muscle endurance. This suggests that the therapeutic approach should focus on de-sensitization of the trigeminal-cervical complex when dealing with the comorbidity of migraine and cervical pain., (© 2023 European Pain Federation - EFIC®.)

Background: Perceived diagnostic uncertainty can leave adolescents confused about their condition and impede their ability to understand "what's wrong with me". Our aim is to develop credible explanations about the condition for adolescents suffering from non-traumatic knee pain., Methods: This multiple-method study integrated findings from two systematic literature searches of qualitative and quantitative studies, an Argumentative Delphi with international experts (n = 16) and think-aloud interviews with adolescents (n = 16). Experts provided feedback with arguments on how to communicate credible explanations to meet adolescents' needs; we analysed feedback using thematic analysis. The explanations were tailored based on the adolescent end-users' input., Results: We screened 3239 titles/abstracts and included 16 papers exploring diagnostic uncertainty from adolescents' and parents' perspectives. Five themes were generated: (1) understanding causes and contributors to the pain experience, (2) feeling stigmatized for having an invisible condition, (3) having a name for pain, (4) controllability of pain, and (5) worried about something being missed. The Argumentative Delphi identified the following themes: (1) multidimensional perspective, (2) tailored to adolescents, (3) validation and reassurance, and (4) careful wording. Merging findings from the systematic search and the Delphi developed three essential domains to address in credible explanations: "What is non-traumatic knee pain and what does it mean?", "What is causing my knee pain?" and "How do I manage my knee pain?", Conclusions: Six credible explanations for the six most common diagnoses of non-traumatic knee pain were developed. We identified three domains to consider when tailoring credible explanations to adolescents experiencing non-traumatic knee pain., Significance: This study provides credible explanations for the six most common diagnoses of non-traumatic knee pain. Additionally, we identified three key domains that may need to be addressed to reduce diagnostic uncertainty in adolescents suffering from pain complaints. Based on our findings, we believe that clinicians will benefit from exploring adolescents' own perceptions of why they experience pain and perceived management strategies, as this information might capture important clinical information when managing these young individuals., (© 2023 European Pain Federation - EFIC ®.)

Background: Expert consensus asserts that early treatment of Complex Regional Pain Syndrome (CRPS) leads to better outcomes. Yet no evidence supports this assumption regarding the recognized gold standard of multidisciplinary functional rehabilitation. To address this, we aimed to establish if there is a difference in outcomes between early CRPS (<1 year symptom duration) and persistent CRPS (= >1 year symptom duration) following rehabilitation and whether any gains are maintained at three months., Method: Secondary analysis was conducted on previously collected clinical Patient Reported Outcome Measures (PROMS) data from 218 patients attending a residential multidisciplinary rehabilitation programme. Datasets were categorized into early CRPS (n = 40) or persistent CRPS (n = 178) dependent on symptom duration. Function, pain, self-efficacy, kinesiophobia and psychological health domains were compared using repeated measures analysis of covariance for a two group design for group difference post rehabilitation and at three month follow-up., Results: Post-rehabilitation, both groups improved in pain, function, kinesiophobia, psychological health and self-efficacy. At three months, the persistent CRPS group maintained improvements in pain and function. This was not achieved in early CRPS., Conclusion: This exploratory study is the first to empirically test the assumption that those with early CRPS have better outcomes following rehabilitation. Our clinical data challenges this, as both early and persistent CRPS groups improved following rehabilitation. Findings indicate that rehabilitation benefits those with CRPS, regardless of symptom duration. However, unlike early CRPS, those with persistent CRPS sustain gains at follow-up. Further prospective exploration is warranted., Significance: Expert consensus recommends early treatment for Complex Regional Pain Syndrome, yet there is little empirical evidence to support this. Our findings are the first to challenge this assumption by revealing no difference in outcomes between early and persistent CRPS post-rehabilitation. However, those with persistent CRPS maintain gains after three months, unlike people with early CRPS (symptoms < one year). These findings are relevant to clinical practice as they challenge established assumptions, suggesting a focus on improving early CRPS follow-up outcomes., (© 2023 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation - EFIC®.)

Objective: To determine the relationship between age and long-term postsurgical analgesic use in patients who underwent elective surgery with neuraxial anaesthesia., Design: Retrospective observational study using data from the National Health Insurance Research Database of Taiwan from 2015 to 2019., Setting: National Health Insurance Research Database of Taiwan., Patients: A total of 12,810 patients (6405 younger and 6405 older) matched using propensity score matching., Interventions: Older (≥65 years)., Measurements: The use of long-term (3 or 6 months) postoperative analgesics, including opioids, as a surrogate marker of chronic postsurgical pain (CPSP) was analysed using logistic regression., Main Results: After 3 months of surgery, older adults had higher use of all analgesics (odds ratio [OR] = 1.15; 95% CI = 1.03-1.28) and opioids (OR = 1.18; 95% CI = 1.09-1.28) compared to younger patients. Similar results were observed after 6 months of surgery (all analgesic use: OR = 1.11; 95% CI = 1.03-1.20; opioid use: OR = 1.33; 95% CI = 1.07-1.81)., Conclusion: The findings from this study suggest that older adults are more likely to experience CPSP and have increased use of long-term analgesics, including opioids, after undergoing elective surgery with neuraxial anaesthesia. The study highlights the need for improved pain management strategies for older adults after surgery., Significance: Older age is an independent risk factor for long-term analgesic use after surgery under neuraxial anaesthesiaanesthesia, indicating an increased risk for chronic postsurgical pain., (© 2023 European Pain Federation - EFIC ®.)

Background and Objective: Low back pain (LBP), and in particular non-specific low back pain (NSLBP), which accounts for approximately 90% of LBP, is the leading cause of years lived with disability worldwide. In clinical trials, LBP is often poorly categorized into 'specific' versus 'non-specific' and 'acute' versus 'chronic' pain. However, a better understanding of the underlying pain mechanisms might improve study results and reduce the number of NSLBP patients., Databases and Data Treatment: Narrative review., Results: NSLBP is a multi-dimensional, biopsychosocial condition that requires all contributing dimensions to be assessed and prioritized. Thereby, the assessment of the contribution of nociceptive, neuropathic and nociplastic pain mechanisms forms the basis for personalized management. In addition, psychosocial (e.g. anxiety, catastrophizing) and contextual factors (e.g. work situation) as well as comorbidities need to be assessed and individually weighted. Personalized treatment of NSLBP further requires individually choosing treatment modalities, for example, exercising, patient education, cognitive-behavioural advice, pharmacotherapy, as well as tailoring treatment within these modalities, for example, the delivery of tailored psychological interventions or exercise programs. As the main pain mechanism and psychosocial factors may vary over time, re-assessment is necessary and treatment success should ideally be assessed quantitatively and qualitatively., Conclusions: The identification of the main contributing pain mechanism and the integration of the patients' view on their condition, including beliefs, preferences, concerns and expectations, are key in the personalized clinical management of NSLBP. In research, particular importance should be placed on accurate characterization of patients and on including outcomes relevant to the individual patient., Significance Statement: Here, a comprehensive review of the challenges associated with the diagnostic label 'non-specific low back pain' is given. It outlines what is lacking in current treatment guidelines and it is summarized what is currently known with respect to individual phenotyping. It becomes clear that more research on clinically meaningful subgroups is needed to best tailor treatment approaches., (© 2023 European Pain Federation - EFIC ®.)

Background: Opioid use has increased substantially as a treatment for chronic pain, although harms from long-term opioid therapy outweigh the benefits. More knowledge about factors associated with long-term opioid use is needed. We aimed to investigate the association between socioeconomic status and long-term opioid use in the period 2010-2019., Methods: This was a nested case-control study in which the cases were all persons ≥18 years with long-term opioid use, that is use of opioids for more than 3 months (N = 215,642). Cases were matched on gender, age and index year (first long-term use period) with four controls who filled at least one opioid prescription, but never developed long-term opioid use in the study period (N = 862,568). We performed a logistic regression analysis adjusted for relevant confounders, stratified on age groups (18-67 years and 68 years and above)., Results: In the younger age group, long-term opioid use was associated with low education (adjusted odds ratio, aOR = 1.54; 95% confidence interval, CI [1.51-1.57]), low income (1.33 [1.31-1.36]), being unemployed (1.40 [1.38-1.42]) and receiving disability pension (1.36 [1.33-1.38]). Weaker associations were found for living in a single-person household or in a dense geographical area. Similar associations were found for the older age group., Conclusion: We found that low socioeconomic status was associated with long-term opioid use both among people in working age and older people. These results indicate a need for social and financial support for non-pharmacological treatment of chronic pain among people with lower socioeconomic status., Significance: This study shows that people with low socioeconomic status are at higher risk of developing long-term opioid use. In the clinical setting, physicians should consider socioeconomic status when prescribing opioids for chronic pain. Non-pharmacological treatment options funded by public health services should be prioritized to those with low socioeconomic status as long-term opioid use in chronic pain patients is not recommended., (© 2023 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation - EFIC ®.)

Background: Activity-based treatments play an integral role in managing musculoskeletal conditions including low back pain. However, while therapeutic exercise has been shown to reduce pain in such conditions, certain individuals experience a paradoxical pain increase in response to exercise. The physiological processes underlying this sensitivity to physical activity (SPA) are not fully understood, however stress and inflammation have been shown to contribute to SPA. The present cross-sectional study investigated whether physiological indicators of stress (cortisol) and inflammation (IL-6) help explain SPA., Methods: Twenty-seven patients with chronic low back pain and 21 healthy controls completed a 1-h exercise session of standardized physical tasks. SPA was calculated from the difference between post- and pre-exercise pain levels. Participant's saliva was collected at several timepoints for cortisol and IL-6 levels quantification. Their waking cortisol response was calculated to reflect their cortisol regulation. Reactivity of IL-6 and cortisol was calculated to reflect changes in these measures during exercise., Results: IL-6 reactivity was significantly and positively correlated with SPA among participants with low back pain. In contrast, neither cortisol waking response nor cortisol reactivity was significantly correlated within the low back pain group. No significant differences in IL-6 reactivity, cortisol reactivity or cortisol waking response were observed., Conclusion: These findings are the first to link SPA to an objective biomarker among people with low back pain. These findings help describe the physiological mechanisms of SPA and can support new clinical research that targets the inflammatory response of patients with chronic low-back pain and elevated SPA., Significance: This study reveals a correlation between SPA and an objective salivary biomarker of IL-6 in people with low back pain, improving our understanding of this clinically relevant subjective experience., (© 2023 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation - EFIC ®.)

Objective: To compare the effects of three types of ultrasound-guided nerve blocks on post-operative recovery quality in patients undergoing modified radical mastectomy for unilateral breast cancer., Methods: In this randomized double-blinded trial (chictr.org.cn, ChiCTR2200059428), 150 female patients were equally assigned to S group (serratus anterior plane block, SAPB) group, P group (paravertebral block, PVB) or ST group (serratus anterior combined with transverse thoracic muscle plane blocks, SA-TTMPB). The primary outcome was QoR-15 at five time points after surgery. Secondary outcomes were pain scores, time of first rescue analgesic and chronic pain incidence at 3 months., Results: The QoR-15 total score of S group at 24 h, 48 h, 72 h and 7 days post-surgery was significantly lower in groups P and ST, while there was no significant difference between groups P and ST (S vs. P vs. ST, 100.29 ± 6.20 vs. 108.51 ± 7.46 vs. 106.46 ± 6.95; 105.59 ± 6.18 vs. 113.06 ± 7.44 vs. 111.22 ± 6.56; 112.51 ± 6.32 vs. 119.88 ± 6.44 vs. 117.62 ± 6.09; 123.00 ± 5.78 vs. 128.86 ± 5.96 vs. 126.92 ± 5.72, p < 0.05). The dynamic and rest NRS scores at 6 and 12 h post-surgery were significantly higher in group S than in groups P and ST., Conclusion: Serratus anterior plane block combined with transverse thoracic muscle plane block and paravertebral block both have better effects than serratus anterior plane block alone in improving patients' early post-operative recovery quality, and also have an advantage in improving early post-operative pain., Clinical Trial Registration: chictr.org.cn (ChiCTR2200059428)., Date of Registration: 29 April 2022., Significance: Serratus anterior combined with transverse thoracic muscle plane block may be a safer, easier, and equally effective nerve block strategy than paravertebral block in patients undergoing modified radical mastectomy for unilateral breast cancer., (© 2023 European Pain Federation - EFIC ®.)

Background: Recent research has found child pain-related injustice appraisals to be associated with adverse pain-related outcomes. However, this evidence is mainly based on research using a measure developed for adults in the context of accident-related injuries, which may not translate to paediatric pain populations. Research on the phenomenology of child pain-related injustice appraisals is lacking. This study aimed to examine the phenomenology of pain-related injustice appraisals among both pain-free children and children living with chronic pain, to compare and contrast their experiences., Methods: Two focus groups were held with pain-free children (n = 16), and three focus groups were held with paediatric chronic pain patients attending a rehabilitation centre (n = 15) in Belgium. Interpretative phenomenological analysis was applied., Results: Two injustice-related themes were generated from the focus groups with pain-free children: (1) 'Someone else is at fault' and (2) 'I am in pain and he is not'. Two injustice-related themes were generated from the focus groups with paediatric chronic pain patients: (1) 'People don't see my pain' and (2) 'I am missing out because of my pain'., Conclusions: This study offers the first exploration of the phenomenology of child pain-related injustice appraisals in both pain-free children and paediatric pain patients. Findings highlight the interpersonal nature of lived injustice experiences caused by chronic pain, which is not fully captured by existing child pain-related injustice measures. Findings further suggest that pain-related injustice notions may not be extrapolated from a chronic to an acute pain context., Significance: The current study offers the first exploration of the phenomenology of child pain-related injustice appraisals in both pain-free children and paediatric chronic pain patients. Findings highlight the interpersonal nature of injustice appraisals that are specific to the experience of chronic rather than acute pain. These appraisals are not fully captured by current child pain-related injustice measures., (© 2023 European Pain Federation - EFIC ®.)

Background and Objective: Psychological treatments for chronic pain have helped many people around the world. They are among the most researched and best evidenced treatments a person can receive when they have persistent, disabling and distressing pain. At the same time, improvements in the effectiveness of these treatments appear to be at a standstill. This may be due to an inherent lack of generalizability from aggregated group data to the individual, limited utility of our current schemes for categorizing people with pain conditions, faced with their inherent heterogeneity, our relatively coarse categories of treatment types and focus on treatment packages rather than individual methods, and our current failures to find adequate predictors of outcome, or to assign people their best-suited treatment methods, based on group data. In this review, it is argued that the development and examination of truly personalized treatment is a next logical step to create progress and improve the results people achieve., Methods: Key research studies pertaining to psychological treatments, treatment outcome, heterogeneity in chronic pain, prediction of treatment outcome, subtyping and treatment tailoring are reviewed., Results and Conclusion: It is suggested that development of future treatments for chronic pain ought to incorporate an idiographic, process-based approach, focused on evidence-based mechanisms of change, individually and dynamically addressed, based on contextually sensitive ongoing assessment. Knowledge and practical solutions needed to make process-based therapy for chronic pain happen are discussed., Significance: Psychological approaches to chronic pain have been highly successful in the past but improvement in the effectiveness of these over time is slow to nonexistent. It is argued here that this has happened due to a failure to adequately consider the individual. Future psychological treatments for chronic pain ought to incorporate an idiographic, process-based approach, focused on evidence-based mechanisms of change, individually and dynamically addressed, grounded in ongoing contextually sensitive assessment., (© 2023 The Author. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation - EFIC ®.)

Background: The treatment of neuropathic pain remains a major unmet need that the development of personalized and refined treatment strategies may contribute to address., Database: In this narrative review, we summarize the various approaches based on objective biomarkers or clinical markers that could be used., Results: In principle, the validation of objective biomarkers would be the most robust approach. However, although promising results have been reported demonstrating a potential value of genomics, anatomical or functional markers, the clinical validation of these markers has only just begun. Thus, most of the strategies documented to date have been based on the development of clinical markers. In particular, many studies have suggested that the identification of specific subgroups of patients presenting with specific combinations of symptoms and signs would be a relevant approach. Two main approaches have been used to identify relevant sensory profiles: quantitative sensory testing and specific patients reported outcomes based on description of pain qualities., Conclusion: We discuss here the advantages and limitations of these approaches, which are not mutually exclusive., Significance: Recent data indicate that various new treatment strategies based on predictive biological and/or clinical markers could be helpful to better personalized and therefore improve the management of neuropathic pain., (© 2023 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation - EFIC ®.)

Background: The prevalence of chronic non-cancer pain (CNCP) has increased dramatically the past decades, which combined with indiscriminate use of prescribed opioids has become a public health problem. Endocrine dysfunction may be a complication of long-term opioid treatment (L-TOT), but the evidence is limited. This study aimed at investigating the associations between L-TOT and endocrine measures in CNCP patients., Methods: Cortisol (spot and after stimulation), thyrotropin (TSH), thyroxin (T4), insulin-like growth factor 1 (IGF-1), prolactin (PRL), 17-hydroxyprogesterone, androstenedione, dehydroepiandrosterone (DHEAS), sex hormone-binding globulin (SHBG), total testosterone (TT) and free testosterone (fT) were measured. Group comparisons were done between CNCP patients in L-TOT and controls as well as between patients on high- or low-dose morphine equivalents., Results: Eighty-two CNCP patients (38 in L-TOT and 44 controls not receiving opioids) were included. Low TT (p = 0.004) and fT concentrations (p < 0.001), high SHBG (p = 0.042), low DEAS (p = 0.017) and low IGF-1 (p = 0.003) in men were found when comparing those in L-TOT to controls and high PRL (p = 0.018), low IGF-1 standard deviation score (SDS) (p = 0.006) along with a lesser, but normal cortisol response to stimulation (p = 0.016; p = 0.012) were found when comparing L-TOT to controls. Finally, a correlation between low IGF-1 levels and high opioid dose was observed (p < 0.001)., Conclusions: Our study not only supports previous findings but even more interestingly disclosed new associations. We recommend future studies to investigate endocrine effects of opioids in larger, longitudinal studies. In the meanwhile, we recommend monitoring endocrine function in CNCP patients when prescribing L-TOT., Significance: This clinical study found associations between L-TOT, androgens, growth hormone and prolactin in patients with CNCP compared to controls. The results support previous studies as well as add new knowledge to the field, including an association between high opioid dose and low growth hormone levels. Compared to existing research this study has strict inclusion/exclusion criteria, a fixed time period for blood sample collection, and adjustments for potential confounders, which has not been done before., (© 2023 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation - EFIC ®.)

Objectives: There is a lack of data on the distribution of women first and senior authorships in pain journals. Using articles published in top North American pain journals over the past two decades, we sought to describe the prevalence and changes in women representation among first and last authors., Methods: We retrieved all published research articles in four pain journals (Regional Anesthesia and Pain Medicine, Clinical Journal of Pain, Pain and The Journal of Pain) from 2002 to 2021 using the easyPubMed package. Subsequently, the 'gender' package in R was used to determine authors' gender by first names. Trends in gender authorship change over time were assessed., Results: The final cohort consisted of 20,981 authors (from an initial total of 11,842 publications and 23,684 authors retrieved). Women authors were more often first compared to senior authors (46.7% vs. 30.5%). The proportion of women first authors (46.2% in 2002 vs. 48.4% in 2021) and women senior authors (22.4% in 2002 vs. 36.3% in 2021) increased over the course of the study period (all p-value <0.001). The Clinical Journal of Pain having the highest percentage of women authors and Regional Anesthesia and Pain Medicine had the lowest percentage of women authors., Discussion: Our data demonstrated increasing women authorship in pain journals in the past 20 years, largely driven by an increase in first authorships. There still remains a large gap between first and senior authorship, indicative of disparity in the role that women play in research., (© 2023 European Pain Federation - EFIC ®.)

Background: We investigated whether a universal predictive risk index for persistent postsurgical pain (PPP) is applicable to patients who undergo total knee arthroplasty (TKA)., Methods: In this cohort study, 392 participants of a randomized study investigating the effects of anaesthesia methods and tourniquet use on TKA were divided into low-, moderate-, and high-risk groups for PPP, as suggested in the previous risk index study. Patients reported pain using the Oxford Knee Score pain subscale and Brief Pain Inventory-short form preoperatively and 3 and 12 months postoperatively. We compared the pain scores of the low- to moderate- and high-risk groups at respective time points and investigated changes in pain scores and the prevalence of PPP at 3 and 12 months after surgery., Results: The high-risk group reported more pain 3 and 12 months after TKA than the low- to moderate-risk group. However, of seven variables, only a single difference reached the threshold for minimal clinical importance between the groups at 12 months. Additionally, at 12 months, the low- to moderate-risk group reported slightly worse improvements in three of seven pain variables than the high-risk group. Depending on the definition, the prevalence of PPP ranged from 2% to 29% in the low- to moderate-risk group and 4% to 41% in the high-risk group 12 months postoperatively., Conclusions: Although the investigated risk index might predict clinically important differences in PPP between the risk groups at 3 months after TKA, it seems poorly applicable for predicting PPP at 12 months after TKA., Significance: Although many risk factors for persistent postsurgical pain after total knee arthroplasty have been identified, predicting the risk of this pain has remained a challenge. Results of the current study suggest that accumulation of previously presented modifiable risk factors might be associated with increased postsurgical pain at 3 months, but not at 12 months after total knee arthroplasty., (© 2023 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation - EFIC ®.)

Background: Alterations in the default mode network (DMN) connectivity across pain stages suggest a possible DMN involvement in the transition to persistent pain., Aim: This study examined whether pain-free DMN connectivity at lower alpha oscillations (8-10 Hz) accounts for a unique variation in experimental peak pain intensity beyond the contribution of factors known to influence pain intensity., Methods: Pain-free DMN connectivity was measured with electroencephalography prior to 1 h of capsaicin-evoked pain using a topical capsaicin patch on the right forearm. Pain intensity was assessed on a (0-10) numerical rating scale and the association between peak pain intensity and baseline measurements was examined using hierarchical multiple regression in 52 healthy volunteers (26 women). The baseline measurements consisted of catastrophizing (helplessness, rumination, magnification), vigilance, depression, negative and positive affect, sex, age, sleep, fatigue, thermal and mechanical pain thresholds and DMN connectivity (medial prefrontal cortex [mPFC]-posterior cingulate cortex [PCC], mPFC-right angular gyrus [rAG], mPFC-left Angular gyrus [lAG], rAG-mPFC and rAG-PCC)., Results: Pain-free DMN connectivity increased the explained variance in peak pain intensity beyond the contribution of other factors (ΔR 2  = 0.10, p = 0.003), with the final model explaining 66% of the variation (R 2  = 0.66, ANOVA: p < 0.001). In this model, negative affect (β = 0.51, p < 0.001), helplessness (β = 0.49, p = 0.007), pain-free mPFC-lAG connectivity (β = 0.36, p = 0.003) and depression (β = -0.39, p = 0.009) correlated significantly with peak pain intensity. Interestingly, negative affect and depression, albeit both being negative mood indices, showed opposing relationships with peak pain intensity., Conclusions: This work suggests that pain-free mPFC-lAG connectivity (at lower alpha) may contribute to individual variations in pain-related vulnerability., Significance: These findings could potentially lead the way for investigations in which DMN connectivity is used in identifying individuals more likely to develop chronic pain., (© 2023 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation - EFIC ®.)

Objective: The aim of this clinical trial was to compare the outcomes of the application of ultrasound-guided percutaneous nerve stimulation (PENS) targeting the median nerve versus surgery for improving pain and function in women with CTS., Methods: In this randomized parallel-group trial (ClinicalTrials.gov, NCT04246216), 70 women with CTS were randomly allocated to either PENS (n = 35) or surgery (n = 35) group. Hand pain intensity (mean pain and the worst pain experienced) was the primary outcome. Functional status and symptoms severity (Boston Carpal Tunnel Questionnaire, BCTQ) and self-perceived improvement (Global Rating of Change, GROC) were the secondary outcomes. Outcomes were assessed at baseline and 1, 3, 6 and 12 months after each intervention. Analysis was performed with intention to treat with mixed ANCOVAs adjusted for baseline outcomes., Results: Analyses showed an adjusted advantage for PENS at 1 (Δ -2.0, 95% CI -2.9 to -1.1) and 3 (Δ -1.4, 95% CI -2.3 to -0.5) months for mean pain, at 1 (Δ -2.2, 95% CI -3.3 to -1.1), 3 (Δ -1.75, 95% CI -2.9 to -0.6) and 6 (Δ -1.7, 95% CI -2.8 to -0.6) months in the worst pain intensity, and at 1 (Δ -0.95, 95% CI -1.1 to -0.8), 3 (Δ -0.55, 95% CI -0.8 to -0.3) and 6 (Δ -0.4, 95% CI -0.6 to -0.8) months in function. Both groups exhibited similar changes in symptom severity. Both groups reported similar improvement at 12 months in all outcomes. Symptoms and function improved in both groups, with PENS leading to better short-term outcomes than surgery., Conclusion: This clinical trial confirms that PENS applied with current understanding of pain mechanisms in CTS is as useful as surgery in women with CTS without denervation. The potential placebo effect of both interventions should not be ignored., Significance: The application of percutaneous nerve stimulation was more effective at short-term, but similar effective at mid and long-term, than surgery in women with carpal tunnel syndrome., (© 2023 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation - EFIC ®.)

Objective: The aim of this systematic review was to appraise and analyse the knowledge on bone-related biochemical and histological biomarkers in complex regional pain syndrome 1 (CRPS 1)., Database: A total of 7 studies were included in the analysis (biochemical analyses n  = 3, animal study n  = 1, histological examination n  = 3)., Results: Two studies were classified as having a low risk of bias and five studies with a moderate risk of bias. Biochemical analysis indicated an increased bone turnover with increased bone resorption (elevated urinary levels of deoxypyridinoline) and bone formation (increased serum levels of calcitonin, osteoprotegerin and alkaline phosphatase). The animal study reported an increased signalling of proinflammatory tumour necrosis factor 4 weeks postfracture, which did, however, not contribute to local bone loss. Histological examination from biopsies revealed thinning and resorption of cortical bone, rarefication and reduction in trabecular bone and vascular modification in the bone marrow in acute CRPS 1, and replacement of the bone marrow by dystrophic vessels in chronic CRPS 1., Conclusion: The limited data reviewed revealed certain potential bone-related biomarkers in CRPS. Biomarkers hold the potential to identify patients who may benefit from treatments that influence bone turnover. Thus, this review identifies important areas for future research in CRPS1 patients., (© 2023 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation - EFIC ®.)