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Wolnei Caumo,1–4 Luciana C Antunes,1 Jéssica Lorenzzi Elkfury,1 Evelyn G Herbstrith,5 Raquel Busanello Sipmann,6 Andressa Souza,7 Iraci LS Torres,1,8 Vinicius Souza dos Santos,1 Randy Neblett9 1Postgraduate Program in Medical Sciences, School of Medicine, 2Pain and Palliative Care Service, Hospital de Clínicas de Porto Alegre, 3Laboratory of Pain and Neuromodulation, 4Surgery Department, School of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, 5School of Psychology, Pontifícia Universidade Católica do Rio Grande do Sul, 6School of Medicine, Universidade Federal do Rio Grande do Sul, 7Postgraduate Program in Health and Human Development, La Salle University Center, Canoas, 8Pharmacology Department, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; 9PRIDE Research Foundation, Dallas, TX, USA Objectives: The primary aim was to assess the psychometric properties (including internal consistency, construct validity, reproducibility, and factor structure) of the Central Sensitization Inventory (CSI), adapted and validated for a Brazilian population (CSI-BP). Additionally, we evaluated the relationship between the CSI-BP and the serum brain-derived neurotrophic factor (BDNF) and determined if the symptoms elicited by the CSI-BP discriminate between subjects who do/do not respond to the conditioned pain modulation (CPM) task, as assessed by change in numeric pain scale (0–10) score. Patients and methods: A cross-sectional study was conducted in a pain clinic in a tertiary teaching hospital. A total of 222 adults with chronic musculoskeletal pain and 63 healthy control subjects completed the CSI-BP and the Brazilian Portuguese pain-catastrophizing scale (BP-PCS). A team of experts translated the CSI according to the international guidelines. Test–retest, item analysis, convergent validity, and factor analysis were performed. Later, a random subsample (n=77) was used to correlate the CSI-BP adjusted index with change in numeric pain-scale score during the CPM task and a BDNF blood sample. Results: The CSI-BP presented strong psychometric properties (test–retest reliability 0.91, Cronbach’s a=0.91). Confirmatory factor analysis yielded a four-factor structure, supporting the original English version. The CSI-BP adjusted index showed moderate positive correlation with the BP-PCS, and classified more than 80% of patients correctly vs healthy controls. Serum BDNF levels explained 27% of the variation in the CSI-BP adjusted index. Subjects with impairment in the descending modulatory system had higher CSI-BP adjusted index scores than subjects who responded normally to the CPM task: 49.35 (12.1) vs 39.5 (12.33), respectively (P

Background: Strong associations have been demonstrated between chronic musculoskeletal pain, pain-related fear-avoidance (FA) of activities of daily living, and functional disability. The Fear Avoidance Components Scale (FACS) is a patient-reported outcome (PRO) measure, which was designed to evaluate cognitive, emotional, and behavioural dimensions of FA. Objective: The study aims were to translate the English version of the FACS into Simplified Chinese and then to examine its psychometric properties. Methods: The translation and cross-cultural adaptation of the FACS from English to Chinese was performed with standard methodology. A group of 330 subjects with chronic musculoskeletal pain completed the FACS-Chi and additional FA-related PRO measures. The FACS-Chi was then completed a second time, 1 week later. Results: The FACS-Chi showed excellent internal consistency (Cronbach's alpha = 0.920) and test-retest reliability (ICC = 0.918). A confirmatory factor analysis of the 2-factor model determined in the original English version of FACS revealed an acceptable fit. Strong correlations were found between FACS-Chi scores and other PRO measures of perceived level of disability, pain catastrophizing, and pain-related anxiety ( p < 0.001 for all analyses). Conclusions: The FACS-Chi demonstrated good psychometric properties, including excellent test-retest reliability and internal consistency and satisfactory construct validity. The FACS-Chi may be a useful measure of pain-related FA in Chinese-speaking patients with chronic musculoskeletal pain., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2024 Zhongyi Tu et al.)

Objectives: The 13-item pain catastrophizing scale (PCS) is the most commonly used measure of pain catastrophizing. A validated Finnish version of the PCS has previously been unavailable. The objectives were to translate the original English version of the PCS into Finnish (PCS-FI), then to evaluate (i) structural validity of the PCS-FI with a confirmatory factor analysis (CFA), (ii) internal reliability with Cronbach's alpha, Omega, and Omega hierarchical, (iii) convergent validity with measures of well-being, quality of life, sleep quality, symptoms of central sensitization, and anxiety, and (iv) known-groups validity between participants with chronic low back pain (CLBP) and pain-free controls., Methods: The translation process was performed with established guidelines. The PCS-FI was psychometrically validated using 92 participants with CLBP and 53 pain-free controls., Results: Structural validity with CFA supported a bifactor solution. However, low reliability was found for the three specific factors ( ω h ranging from 0.14 to 0.18) compared to the general factor ( ω h = 0.88) suggesting that only the total score should be used. Convergent validity analysis showed satisfactory correlations and medium effect sizes with the other patient-reported outcome measures. Participants with CLBP had significantly higher total PCS-FI scores than pain-free controls., Conclusions: The PCS-FI appears to be a valid and reliable instrument for assessing pain-related catastrophizing in Finnish-speaking populations. Ethical approval for this study was obtained from the Research Ethics Committee of the Northern Savo Hospital District, identification number 2131/2022, on the 31st of January 2022., (© 2024 the author(s), published by De Gruyter.)

Background: The Fear-Avoidance Components Scale (FACS) is a reliable and valid instrument widely used to assess fear-avoidance beliefs related to pain and disability. However, there is a scarcity of validated translations of the FACS in different cultural and linguistic contexts, including the French population. This study aimed to translate and validate the French version of the FACS (FACS-Fr/CF), examining its psychometric properties among French-speaking individuals., Methods: A cross-cultural translation process-including forward translation, backward translation, expert committee review, and pre-testing-was conducted to develop the FACS-Fr/CF. The translated version was administered to a sample of French-speaking adults (n = 55) with chronic musculoskeletal pain. Internal consistency (including confirmatory analyses of the 2 factors identified in the Serbian version), test-retest reliability and convergent validity were then assessed., Results: The FACS-Fr/CF demonstrated high global internal consistency (α = 0.94, 95% CI: 0.91-0.96) as well as high internal consistency of the 2 factors identified in the Serbian version (α = 0.90, 95% CI: 0.86-0.94 and α = 0.90, 95% CI: 0.85-0.94, respectively). Test-retest analysis revealed a moderate (close to high) reliability (ICC = 0.89; 95% CI: 0.82-0.94 and r = 0.89; p<0.005). Convergent validity was supported by significant correlations between the FACS-Fr/CF scores and the Tampa Scale for Kinesiophobia (r = 0.82; p < 0.005), the Pain Catastrophizing Scale (r = 0.72; p < 0.005) and the Hospital Anxiety and Depression Scale (r = 0.66; p < 0.005)., Conclusion: The present study provides evidence for the cross-cultural translation and psychometric validation of the FACS-Fr/CF. The FACS-Fr/CF exhibits a high internal consistency, a moderate (close to high) test-retest reliability, and good construct validity, suggesting its utility in assessing fear-avoidance beliefs in the French-speaking population. This validated tool can enhance the assessment and understanding of fear-avoidance behaviors and facilitate cross-cultural research in pain-related studies., Competing Interests: NO - The authors have declared that no competing interests exist., (Copyright: © 2023 Duport et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Pain can be present in up to 50% of people with post-COVID-19 condition. Understanding the complexity of post-COVID pain can help with better phenotyping of this post-COVID symptom. The aim of this study is to describe the complex associations between sensory-related, psychological, and cognitive variables in previously hospitalized COVID-19 survivors with post-COVID pain, recruited from three hospitals in Madrid (Spain) by using data-driven path analytic modeling. Demographic (i.e., age, height, and weight), sensory-related (intensity or duration of pain, central sensitization-associated symptoms, and neuropathic pain features), psychological (anxiety and depressive levels, and sleep quality), and cognitive (catastrophizing and kinesiophobia) variables were collected in a sample of 149 subjects with post-COVID pain. A Bayesian network was used for structural learning, and the structural model was fitted using structural equation modeling (SEM). The SEM model fit was excellent: RMSEA < 0.001, CFI = 1.000, SRMR = 0.063, and NNFI = 1.008. The only significant predictor of post-COVID pain was the level of depressive symptoms (β=0.241, p = 0.001). Higher levels of anxiety were associated with greater central sensitization-associated symptoms by a magnitude of β=0.406 (p = 0.008). Males reported less severe neuropathic pain symptoms (−1.50 SD S-LANSS score, p < 0.001) than females. A higher level of depressive symptoms was associated with worse sleep quality (β=0.406, p < 0.001), and greater levels of catastrophizing (β=0.345, p < 0.001). This study presents a model for post-COVID pain where psychological factors were related to central sensitization-associated symptoms and sleep quality. Further, maladaptive cognitions, such as catastrophizing, were also associated with depression. Finally, females reported more neuropathic pain features than males. Our data-driven model could be leveraged in clinical trials investigating treatment approaches in COVID-19 survivors with post-COVID pain and can represent a first step for the development of a theoretical/conceptual framework for post-COVID pain.

Introduction: The On&Out study is aimed at assessing the effectiveness, cost-utility and physiological underpinnings of the FIBROWALK multicomponent intervention conducted in two different settings: online (FIBRO-On) or outdoors (FIBRO-Out). Both interventions have proved to be efficacious in the short-term but there is no study assessing their comparative effectiveness nor their long-term effects. For the first time, this study will also evaluate the cost-utility (6-month time-horizon) and the effects on immune-inflammatory biomarkers and Brain-Derived Neurotrophic Factor (BDNF) levels of both interventions. The objectives of this 6-month, randomized, controlled trial (RCT) are 1) to examine the effectiveness and cost-utility of adding FIBRO-On or FIBRO-Out to Treatment-As-Usual (TAU) for individuals with fibromyalgia (FM); 2) to identify pre-post differences in blood biomarker levels in the three study arms and 3) to analyze the role of process variables as mediators of 6-month follow-up clinical outcomes. Methods and analysis: Participants will be 225 individuals with FM recruited at Vall d'Hebron University Hospital (Barcelona, Spain), randomly allocated to one of the three study arms: TAU vs. TAU + FIBRO-On vs. TAU + FIBRO-Out. A comprehensive assessment to collect functional impairment, pain, fatigue, depressive and anxiety symptoms, perceived stress, central sensitization, physical function, sleep quality, perceived cognitive dysfunction, kinesiophobia, pain catastrophizing, psychological inflexibility in pain and pain knowledge will be conducted pre-intervention, at 6 weeks, post-intervention (12 weeks), and at 6-month follow-up. Changes in immune-inflammatory biomarkers [i.e., IL-6, CXCL8, IL-17A, IL-4, IL-10, and high-sensitivity C-reactive protein (hs-CRP)] and Brain-Derived Neurotrophic Factor will be evaluated in 40 participants in each treatment arm (total n = 120) at pre- and post-treatment. Quality of life and direct and indirect costs will be evaluated at baseline and at 6-month follow-up. Linear mixed-effects regression models using restricted maximum likelihood, mediational models and a full economic evaluation applying bootstrapping techniques, acceptability curves and sensitivity analyses will be computed. Ethics and dissemination: This study has been approved by the Ethics Committee of the Vall d'Hebron Institute of Research. The results will be actively disseminated through peer-reviewed journals, conference presentations, social media and various community engagement activities. Trial registration number NCT05377567 (clinicaltrials.gov)., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Serrat, Ferrés, Auer, Almirall, Lluch, D’Amico, Maes, Lorente, Navarrete, Montero-Marín, Neblett, Nijs, Borràs, Luciano and Feliu-Soler.)

Pain after an acute Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19) condition (post-COVID pain) is becoming a new healthcare emergency. Precision medicine refers to an evidence-based method of grouping patients based on their diagnostic/symptom presentation and then tailoring specific treatments accordingly. Evidence suggests that post-COVID pain can be categorized as nociceptive (i.e., pain attributable to the activation of the peripheral receptive terminals of primary afferent neurons in response to noxious chemical, mechanical, or thermal stimuli), neuropathic (i.e., pain associated with a lesion or disease of the somatosensory nervous system and limited to a "neuroanatomically plausible" distribution of the system), nociplastic (i.e., pain arising from altered nociception despite no clear evidence of actual or threatened tissue damage causing the activation of peripheral nociceptors or evidence for disease or lesion of the somatosensory system causing the pain), or mixed type (when two pain phenotypes co-exist). Each of these pain phenotypes may require a different treatment approach to maximize treatment effectiveness. Accordingly, the ability to classify post-COVID pain patients into one of these phenotypes would likely be critical for producing successful treatment outcomes. The 2021 International Association for the Study of Pain (IASP) clinical criteria and grading system provide a framework for classifying pain within a precision pain medicine approach. Here we present data supporting the possibility of grouping patients with post-COVID pain into pain phenotypes, using the 2021 IASP classification criteria, with a specific focus on nociplastic pain, which is probably the primary mechanism involved in post-COVID pain. Nociplastic pain, which is usually associated with comorbid symptomology (e.g., poor sleep quality, fatigue, cognitive-emotional disturbances, etc.) and is considered to be more difficult to treat than other pain types, may require a more nuanced multimodal treatment approach to achieve better treatment outcomes.

Background: Central sensitization is an amplification of neuronal signaling within the central nervous system. The Central Sensitization Inventory was introduced in 2012. A Polish version of the CSI (CSI-Pol) was developed in 2019, but it was not psychometrically validated. The aim of this study was to validate the CSI-Pol in a sample of Polish-speaking patients with chronic spinal pain and compare them with a group of healthy control subjects., Methods: The CSI-Pol was administered to 151 patients with chronic spinal pain recruited from two centers. It was re-administered 7 days later. The psychometric properties were then evaluated, including test-retest reliability, construct validity, factor structure and internal consistency. We correlated the CSI-Pol with functional scales, depression and social support scales and compared CSI-Pol scores in the clinical subjects with 30 healthy control subjects recruited from medical staff and their families., Results: The CSI-Pol demonstrated excellent internal consistency (Cronbach's α =0,933) and test-retest reliability (Intraclass Correlation Coefficients - ICC =0.96), as well as significant positive associations with other patient-reported scales, including the Neck Disability Index (r = 0.593), Revised Oswestry Low Back Pain Disability Questionnaire (r = 0.422), and other measures of functional and depressive states. An exploratory factor analysis resulted in a 4-factor model. CSI-Pol scores in the clinical sample (35.27 ± 17.25) were significantly higher than the control sample (23.3 ± 8.9)., Conclusion: The results of this study suggest that the CSI-Pol may be a useful clinical tool for assessing central sensitization related symptoms and guiding appropriate treatment in Polish-speaking patients with spinal pain., (© 2021. The Author(s).)

Objectives: The aim of this study was to translate the Central Sensitization Inventory (CSI) into the Turkish language, to perform a psychometric validation, and to investigate its reliability in patients with chronic spinal pain with an organic origin, patients with fibromyalgia, and pain-free control individuals., Patients and Methods: Between April 2016 and February 2017, the translation of the original English version of the CSI into Turkish was performed using the forward-backward translation method. A total of 100 fibromyalgia patients (6 males, 94 females; mean age: 45.0±8.4 years; range, 25 to 60 years), 100 patients with chronic spinal pain with an identified organic origin (CSPO), (10 males, 90 females; mean age: 43.8±9.7 years; range, 21 to 60 years), and 100 healthy controls (8 males, 92 females; mean age: 35.8±10.1 years; range, 25 to 55 years) were included in the study. Demographic characteristics were collected. Test-retest reliability was determined by re-administering the CSI-Turkish (CSI-Turk) two weeks after the first application., Results: The internal consistency (Cronbach's alpha) was found to be 0.92 and the intraclass correlation coefficient was 0.93. Patients with fibromyalgia, a very common central sensitivity syndrome (CSS), had the highest mean CSI-Turk scores, and healthy controls had the lowest. Using the recommended cut-off score of 40 resulted in 87% sensitivity and 90% specificity in distinguishing between fibromyalgia and control individuals., Conclusion: This study suggests that the CSI-Turk can be effectively used as a screening tool to elucidate CS-related symptomology among patients with chronic pain with a high internal consistency, test-retest reliability, sensitivity, and specificity., Competing Interests: Conflict of Interest: The authors declared no conflicts of interest with respect to the authorship and/or publication of this article., (Copyright © 2021, Turkish League Against Rheumatism.)

Background: The Central Sensitization Inventory (CSI) is a screening tool designed to detect symptoms related to Central Sensitization (CS) and Central Sensitivity Syndromes (CSS) by measuring the degree of related phenomena. The objective of this study was to create a German, culturally-adapted version of the CSI and to test its psychometric properties., Methods: A German version of the CSI (CSI-GE) was developed, culturally-adapted, and pretested for comprehensibility. The psychometric properties of the resulting version were validated in a clinical study with chronic pain and pain-free control subjects. To assess retest reliability, the CSI-GE was administered twice to a subgroup of patients. Structural validity was tested using factor analyses. To investigate construct validity a hypotheses testing approach was used, including (1) correlations between the CSI-GE and several other well-established questionnaires as well as (2) an investigation of the CSI-GE discriminative power between different subgroups of participants believed to have different degrees of CS., Results: The CSI-GE showed excellent reliability, including high test-retest characteristics. Factor analyses confirmed a bi-factor dimensionality as has been determined previously. Analysing construct validity 6 out of 11 hypotheses (55%) were met. CSI-GE scores differentiated between subgroups according to expectations. Correlations between CSI-GE scores and other questionnaires suggested that none of the correlated constructs was identical, but there was overlap with other questionnaires based on symptom load. Several correlations did not fit with our current understanding of CS., Conclusion: The CSI-GE appears to be a reliable tool for measuring CS/CSS-related symptomatology. Whether this implies that the CSI-GE measures the degree of CS within an individual subject remains unknown. The resulting score should be interpreted cautiously until further clarification of the construct., (© 2021. The Author(s).)

The Pain Disability Questionnaire (PDQ) has established itself as a leading patient-reported outcome measure for assessing both mental and physical components of pain-related disability. The current study aimed to translate the PDQ into Serbian and validate its psychometric properties. Following a standard translation process, a total of 554 chronic pain patients (average age 55.37 ± 12.72 years; 375 (67.5%) females) completed the PDQ-Serb, Oswestry Disability Index (ODI), Short Form-36 (SF-36), pain intensity rating and a six-minute walk test (6MWT). Responsiveness was examined in a subsample of 141 patients who completed an inpatient rehabilitation program. The internal consistency of the PDQ-Serb was excellent (Cronbach α = 0.92) and test-retest reliability was favorable (ICC = 0.87). Factor analyses found a bifactor model to be the best fit (CFI = 0.97: TLI = 0.96: RMSEA = 0.05; SRMR = 0.03). Statistically significant Pearson's coefficient correlations ( p < 0.001) were found between the PDQ-Serb and ODI (r = 0.786), SF-36 Physical Components summary (r = -0.659), SF-36 Mental Components summary (r = -0.493), pain intensity rating (r = 0.572), and 6MWT (r = -0.571). Significant post-treatment improvements following inpatient rehabilitation were found with the PDQ-Serb ( p < 0.001; effect size 0.431) and other clinical variables ( p < 0.001; effect sizes from 0.367 to 0.536). The PDQ-Serb was shown to be a reliable and valid self-report instrument for the evaluation of pain-related disability.

Background: Central Sensitization (CS) involves dysfunction in neurophysiological mechanisms that increase neuronal responses to both noxious and non-noxious stimuli in the central nervous system. The Central Sensitization Inventory (CSI) is considered the leading patient-reported outcome measure for assessing CS-related symptoms. The aim of this study was to translate and cross-culturally adapt the CSI into Finnish (CSI-FI) and to evaluate its psychometric properties., Methods: Translation and cross-cultural validation of the CSI was conducted according to established guidelines. The validation sample was 229 subjects, including 42 pain free controls and 187 subjects with chronic musculoskeletal pain. The CSI-FI was evaluated for internal consistency, test-retest reliability, exploratory factor analysis with maximum likelihood extraction, relationship with subject-reported outcome measures [Tampa scale of kinesiophobia (TSK), the Depression scale (DEPS), 5-level EQ-5D version (EQ-5 L-5D), Roland-Morris Disability Questionnaire (RMDQ), and Pain and Sleep Questionnaire Three-Item Index (PSQ-3)], pain history, subjective symptoms of dizziness, and CS-related diagnoses on CSI part B. Furthermore, we studied the ability of the CSI-FI to distinguish pain free controls, subjects with chronic pain in a single body area, and subjects with multisite chronic pain. In addition, we studied the relationship of CSI-FI scores with postural control on a force plate., Results: The CSI-FI demonstrated good internal consistency (0.884) and excellent test-retest reliability (0.933) with a 7 ± 1 day gap between test administrations. Exploratory factor analysis with maximum likelihood extraction yielded a one factor solution. Fair to good correlations were found between the CSI-FI and the TSK, DEPS, EQ-5 L-5D, RMDQ, and PSQ-3. Subjective symptoms of dizziness correlated better with CSI-FI scores than any of the CS-related diagnoses on CSI part B. Total CSI-FI scores successfully distinguished between pain free controls, subjects with chronic pain in a single body area, and subjects with multisite chronic pain. The multisite pain group reported significantly more dizziness symptoms than the other two groups. Force plate measurements showed no relationship between postural control and CSI-FI scores., Conclusion: The CSI-FI translation was successfully cross-culturally adapted and validated into Finnish. CSI-FI psychometric properties and scores were all in acceptable levels and in line with previous CSI validations. The CSI-FI appears to be a valid and reliable instrument for assessing CS-related symptomology in Finnish-speaking populations.

Objective: Chronic musculoskeletal pain disorders (CMPDs) are among the leading causes of disabilities across populations, resulting in high social and financial burden. This persistent pain condition may include the central sensitization (CS) phenomenon, which implies a wide range of symptoms and that may be taken into account in CMPD treatment. CS symptoms can be measured by the Central Sensitization Inventory (CSI). The aims of the study were to describe CS symptoms in patients suffering from several CMPDs and to analyze differences due to gender, age, and body mass index (BMI)., Design: This cross-sectional study recruited a total of 395 Spanish participants suffering from several CMPDs., Setting: CS symptoms were measured with the Spanish Version of the CSI. The total score (0-100) and a cutoff score of 40 were recorded., Subjects: A total of 395 participants were included., Results: The mean CSI total score for the whole sample was 24.6 ± 12.0 points. CSI total score had subclinical values in the whole sample, whereas participants with scores >40 were found across different CMPDs, such as low back pain (37.8%) and neck pain (32.4%); 14.6% of females and 1.7% of males presented CSI scores >40. Patients showed significant differences in CSI cutoff point by gender (P = 0.010) and CSI total score by age (P = 0.014)., Conclusions: Given the high prevalence of clinically relevant CSI scores (>40) in people with a CMPD, especially low back pain and neck pain, we recommend that clinicians supplement their assessment with the CSI for improved decision-making during treatment., (© The Author(s) 2020. Published by Oxford University Press on behalf of the American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objectives: The goal of this study was to identify central sensitization-related symptom severity subgroups in a large multicountry sample composed of patients with chronic pain and pain-free individuals using the Central Sensitization Inventory (CSI)., Methods: A large, pooled international (N = 8 countries) sample of chronic pain patients plus healthy subjects (total N = 2,620) was randomly divided into two subsamples for cross-validation purposes. First, a hierarchical cluster analysis (HCA) was performed using CSI item-level data as clustering variables (test sample; N = 1,312). Second, a latent profile analysis (LPA) was conducted to confirm the optimal number of CSI clusters (validation sample; N = 1,308). Finally, to promote implementation in real-world clinical practice, we built a free online Central Sensitization Inventory Symptom Severity Calculator., Results: In both HCA (N = 1,219 valid cases) and LPA (N = 1,245 valid cases) analyses, a three-cluster and three-profile solution, respectively, emerged as the most statistically optimal and clinically meaningful. Clusters were labeled as follows: (i) Low Level of CS-Related Symptom Severity, (ii) Medium Level of CS-Related Symptom Severity, and (iii) High Level of CS-Related Symptom Severity., Conclusions: Our results indicated that a three-cluster solution clearly captured the heterogeneity of the CSI data. The calculator might provide an efficient way of classifying subjects into the cluster groups. Future studies should analyze the extent to which the CSI cluster classification correlates with other patient-reported and objective signs and symptoms of CS in patients with chronic pain, their associations with clinical outcomes, health-related costs, biomarkers, (etc.), and responsiveness to treatment., (© The Author(s) 2020. Published by Oxford University Press on behalf of the American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Central sensitization is thought to be an important contributing factor in many chronic pain disorders. The Central Sensitization Inventory (CSI) is a patient-reported measure frequently used to assess symptoms related to central sensitization. The aims of the study were to translate and cross-culturally adapt the CSI into Nepali (CSI-NP) and assess its measurement properties., Methods: The CSI was translated into Nepali using recommended guidelines. The CSI-NP was then administered on 100 Nepalese adults with sub-acute and chronic musculoskeletal pain with additional demographic and pain-related questions. The CSI-Nepali was administered again about 2 weeks later. Four measurement properties of the CSI-NP were evaluated: (1) internal consistency using Cronbach's alpha, (2) test-retest reliability using intraclass correlation coefficient (ICC 2,1 ), (3) measurement errors, and (4) construct validity testing five a priori hypotheses. Confirmation of construct validity was determined if a minimum of 75% of the hypotheses were met., Results: The CSI was successfully translated into Nepali. Internal consistency and test-retest reliability were both excellent (Cronbach's alpha = 0.91, and ICC = 0.98). The standard error of measurement was 0.31 and the smallest detectable change was 0.86. Four out of five (80%) a priori hypotheses were met, confirming the construct validity: the CSI-NP correlated strongly with the Pain Catastrophizing Scale total scores (r = 0.50); moderately with the total number of pain descriptors (r = 0.35); weakly with the Numerical Rating Scale (r = 0.25); and women had significantly higher CSI scores than men. However, the CSI scores did not correlate significantly with the total duration of pain, as hypothesized (r = 0.10)., Conclusions: The Nepali translation of the CSI demonstrated excellent reliability and construct validity in adults with musculoskeletal pain. It is now available to Nepali health care providers to help assess central sensitization-related signs and symptoms in individuals with musculoskeletal pain in research or clinical practice to advance the understanding of central sensitization in Nepalese samples.

Background: Pain-related fear-avoidance (FA) is a common problem affecting many patients with painful medical conditions. As there is great interest in the clinical importance of the relationship between FA and disability, several questionnaires have been developed to measure FA. The Fear-Avoidance Components Scale (FACS) is a recently developed patient-reported instrument that addresses critical issues not previously considered in previous FA-related questionnaires. The original English version of the FACS demonstrated good reliability, internal consistency, and construct, criterion, and predictive validity. Two factors were determined: General Fear Avoidance and Types of Activities That are Avoided. The aim of this study was to to translate the FACS into European-style Spanish (FACS-Sp), and validate its psychometric properties., Methods: This two-stage psychometric study included 330 subjects with various chronic musculoskeletal pain disorders. An initial translation and cross-cultural adaptation of the FACS, from English to Spanish, was performed. Then, critical psychometric properties were analysed, including internal consistency by Cronbach's α coefficients, structural validity from the Maximum Likelihood Extraction (MLE), and convergent validity by Pearson correlation with the Central Sensitization Inventory (CSI)., Results: This study reports for the first time the psychometric properties of the Spanish version of the FACS. Total scores ranged from 0 to 88 points, with a mean of 30.49 (±17.18). The FACS-Sp showed a high internal consistency for factor 1 (α = 0.902) and factor 2 (α = 0.88). Factor structure was two-dimensional and supported structural validity, accounting for 48.75% of the total variance. Convergent validity analysis found a significant Pearson correlation r = 0.414., Conclusion: This study reports for the first time the psychometric properties of the Spanish version of the FACS-Sp. Psychometric properties supported the validation of FACS-Sp and ensured the conceptual equivalence with the original English version. In primary care and chronic pain rehabilitation, FA assessment is crucial for clinical decision-making and treatment guidance. The FACS-Sp offers a new measure of FA in Spanish speaking populations. Future research on the FACS-Sp should evaluate test-retest reliability, treatment responsiveness and psychometric comparisons with other translated versions.

Objective: The Fear Avoidance Components Scale (FACS) is a new patient-reported outcome (PRO) questionnaire designed to comprehensively evaluate fear avoidance (FA) beliefs and attitudes in persons with painful medical conditions. The original English version has demonstrated acceptable psychometric properties, including concurrent and predictive validity. Two factors have been identified: 1. general fear avoidance; and 2. types of activities that are avoided., Methods: The FACS was first translated into Serbian, and then psychometrically validated. A cohort of 322 chronic musculoskeletal pain subjects completed the FACS-Serb and additional FA-related patient-reported outcome (PRO) measures. Their FACS-Serb scores were then compared to a cohort of 68 acute pain subjects., Results: Test-retest reliability (ICC2,1 = 0.928) and internal consistency for both Factors (Cronbach α 0.904 and 0,880 respectively) were very good. An acceptable fit was found with a confirmatory factor analysis of the 2-factor model found with the original English version of the FACS. Strong associations were found among FACS-Serb scores and other PRO measures of pain catastrophizing, depressive/anxiety symptoms, perceived disability, and pain intensity (p<0.001 for all analyses). FACS-Serb total scores, separate Factor scores, and subjective pain ratings were significantly higher in the chronic vs. acute pain cohorts (p<0.001 for all analyses)., Conclusions: The FACS-Serb demonstrated strong psychometric properties, including strong reliability and internal consistency, criterion validity (through associations with other FA-related PRO measures), and discriminant validity (through comparisons with a separate acute pain cohort). The FACS-Serb appears to be a potentially useful pain-related assessment tool., Competing Interests: The authors have declared that no competing interests exist.

Purpose Functional restoration programs (FRPs), for patients with chronic disabling occupational musculoskeletal disorders (CDOMDs), have consistently demonstrated positive socioeconomic treatment outcomes, including decreased psychosocial distress and increased work return. The pre-treatment length of disability (LOD), or time between injury and treatment admission, has been shown to influence FRP work outcomes. Some studies have found that shorter LOD is associated with better work outcomes. However, few studies have actually examined cohorts with LOD duration longer than 18 months. This present study evaluated the effects of extended LOD (beyond 18 months) on important treatment outcomes. Methods A total cohort of 1413 CDOMD patients entered an FRP. Of those, 312 did not complete the program, so they were eliminated from outcome analyses. The 1101 patients who completed the FRP were classified based on LOD: Late Rehabilitation (LR, 3-6 months, n = 190); Chronic Disability (CD, 7-17 months, n = 494); and Late Chronic Disability (LCD). The LCD, in turn, consisted of four separate subgroups: 18-23 months (LCD-18, n = 110); 24-35 months (LCD-24, n = 123); 36-71 months (LCD-36, n = 74); and 72+ months (LCD-72, n = 110). Patients were evaluated upon admission and were reassessed at discharge. Those patients who chose to pursue work goals post-treatment (n = 912) were assessed 1-year later. Results Longer LOD was associated with less likelihood of completing the FRP (p < .001). Compared to the other LOD groups, a relatively large percentage of patients (47%) in the longest- disability group were receiving social security disability benefits. Associations were found between longer LOD and more severe patient-reported pain, disability, and depressive symptoms at treatment admission. At discharge, symptom severity decreased for these patient-reported variables in all LOD groups (p < .001). Using binary logistic regressions, it was found that LOD significantly predicted work-return (Wald = 11.672, p = .04) and work-retention (Wald = 11.811, p = .04) after controlling for covariates. Based on the LOD groups, the percentage of patients returning to, and retaining work, ranged from 75.6 to 94.1%, and from 66.7 to 86.3%, respectively. The odds of LCD-24 and LCD-72 patients returning to work were 2.9, and 7.4, respectfully, less likely, compared to LR patients. Furthermore, the odds of LCD-24 and LCD-72 patients retaining work were 3.3 and 3.8 times, respectively, less likely, compared to LR patients. Conclusions Long LOD was a risk factor for FRP non-completion, and was associated with more severe patient-reported variables, including pain intensity and perceived disability. Furthermore, long LOD was a significant predictor for work outcomes at 1 year following FRP discharge. Nevertheless, a large percentage of longer LOD (>24 months) patients had returned to work within the year after discharge (above 85%), and had retained at least part-time work 1-year later (above 66%). These results support the effectiveness of the FRP in mitigating the effects of extended LOD in a large percentage of long-term LOD patients.

Purposing: The Central Sensitization Inventory (CSI) is a new patient-reported instrument, which measures symptoms related to Central Sensitivity Syndromes and Central Sensitization. The aim of this study was to translate the CSI into Spanish, and then to perform a psychometric validation, including a factor analysis to reveal the underlying structure., Methods: In this two-stage psychometric study participated 395 subjects with various chronic pain conditions and that were recruited from two Primary Care Centres. The CSI was cross-culturally adapted to Spanish through double forward and backward translations. The psychometric properties were then evaluated with analyses of construct validity, factor structure and internal consistency. One subgroup (n = 45) determined test-retest reliability at 7 days., Results: The Spanish Version of CSI demonstrated high internal consistency (α = 0.872) and test-retest reliability (r = 0.91). Factor structure was one-dimensional and supported construct validity., Conclusions: The psychometric properties of the Spanish version were found to be strong, with high test-retest reliability and internal consistency, with similar psychometric properties to the English language version. Unlike the English version, however, a one factor solution was found to be a best fit for the Spanish version.

Biofeedback is a process in which biological information is measured and fed back to a patient and clinician for the purpose of gaining increased awareness and control over physiological domains. Surface electromyography (SEMG), a measure of muscle activity, allows both a patient and clinician to have direct and immediate access to muscle functioning that is not possible with manual palpation or visual observation. SEMG biofeedback can be used to help "down-train" elevated muscle activity or to "up-train" weak, inhibited, or paretic muscles. This article presents a historical and clinical overview of SEMG and its use in chronic low back pain assessment and biofeedback training.

Purpose: To determine how the economy affects psychosocial and socioeconomic treatment outcomes in a cohort of chronic disabling occupational musculoskeletal disorder (CDOMD) patients who completed a functional restoration program (FRP)., Methods: A cohort of 969 CDOMD patients with active workers' compensation claims completed an FRP (a medically-supervised, quantitatively-directed exercise progression program, with multi-modal disability management). A good economy (GE) group (n = 532) was released to work during a low unemployment period (2005-2007), and a poor economy (PE) group (n = 437) was released during a higher unemployment period (2008-2010). Patients were evaluated upon admission for demographic and psychosocial variables, and were reassessed at discharge. Socioeconomic outcomes, including work return and work retention 1 year post-discharge, were collected., Results: Some significant differences in psychosocial self-report data were found, but most of the effect sizes were small, so caution should be made when interpreting the data. Compared to the PE group, the GE group reported more depressive symptoms and disability at admission, but demonstrated a larger decrease in depressive symptoms and disability and increase in self-reported quality of life at discharge. The PE group had lower rates of work return and retention 1-year after discharge, even after controlling for other factors such as length of disability and admission work status., Conclusions: CDOMD patients who completed an FRP in a PE year were less likely to return to, or retain, work 1-year after discharge, demonstrating that a PE can be an additional barrier to post-discharge work outcomes. A difference in State unemployment rates of <3% (7 vs. 5%) had a disproportionate effect on patients' failure to return to (19 vs. 6%) or retain (28 vs. 15%) work.

Unlabelled: Central sensitization (CS) is a proposed physiological phenomenon in which central nervous system neurons become hyperexcitable, resulting in hypersensitivity to both noxious and non-noxious stimuli. The term central sensitivity syndrome (CSS) describes a group of medically indistinct (or nonspecific) disorders, such as fibromyalgia, chronic fatigue syndrome, and irritable bowel syndrome, for which CS may be a common etiology. In a previous study, the Central Sensitization Inventory (CSI) was introduced as a screening instrument for clinicians to help identify patients with a CSS. It was found to have high reliability and validity (test-retest reliability = .82; Cronbach's alpha = .88). The present study investigated a cohort of 121 patients who were referred to a multidisciplinary pain center, which specializes in the assessment and treatment of complex pain and psychophysiological disorders, including CSSs. A large percentage of patients (n = 89, 74%) met clinical criteria for one or more CSSs, and CSI scores were positively correlated with the number of diagnosed CSSs. A receiver operating characteristic analysis determined that a CSI score of 40 out of 100 best distinguished between the CSS patient group and a nonpatient comparison sample (N = 129) (area under the curve = .86, sensitivity = 81%, specificity = 75%)., Perspective: The CSI is a new self-report screening instrument to help identify patients with CSSs, including fibromyalgia. The present study investigated CSI scores in a heterogeneous pain population with a large percentage of CSSs, and a normative nonclinical sample to determine a clinically relevant cutoff value., (Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.)