Corrigendum to "Study protocol for the follow-up examination of the Nor-Hand study: A hospital-based observational cohort study exploring pain and biomarkers in people with hand osteoarthritis" [Osteoarthr. Cartil. Open 3 (2021) 100198].

[This corrects the article DOI: 10.1016/j.ocarto.2021.100198.].

2023 EULAR recommendations on imaging in diagnosis and management of crystal-induced arthropathies in clinical practice.

OBJECTIVE: To formulate evidence-based recommendations and overarching principles on the use of imaging in the clinical management of crystal-induced arthropathies (CiAs). METHODS: An international task force of 25 rheumatologists, radiologists, methodologists, healthcare professionals and patient research partners from 11 countries was formed according to the EULAR standard operating procedures. Fourteen key questions on the role of imaging in the most common forms of CiA were generated. The CiA assessed included gout, calcium pyrophosphate deposition disease and basic calcium phosphate deposition disease. Imaging modalities included conventional radiography, ultrasound, CT and MRI. Experts applied research evidence obtained from four systematic literature reviews using MEDLINE, EMBASE and CENTRAL. Task force members provided level of agreement (LoA) anonymously by using a Numerical Rating Scale from 0 to 10. RESULTS: Five overarching principles and 10 recommendations were developed encompassing the role of imaging in various aspects of patient management: making a diagnosis of CiA, monitoring inflammation and damage, predicting outcome, response to treatment, guided interventions and patient education. Overall, the LoA for the recommendations was high (8.46-9.92). CONCLUSIONS: These are the first recommendations that encompass the major forms of CiA and guide the use of common imaging modalities in this disease group in clinical practice.

Lifestyle factors predict gout outcomes: Results from the NOR-Gout longitudinal 2-year treat-to-target study.

OBJECTIVE: Gout is associated with lifestyle, body mass index (BMI) and comorbidities, including dyslipidaemia. We studied how in actively treated patients, anthropometric measures and lipid levels changed over 2 years and whether they predicted gout outcomes. METHODS: Patients with a recent gout flare and elevated serum urate (sUA) received gout education and treat-to-target urate-lowering therapy over 1 year. Anthropometric measures with BMI, waist circumference (WC) and waist-height ratio (WHR) as well as lipid levels were measured yearly over 2 years. We examined whether baseline anthropometric measures and lipid levels were related to flares and to achieving the sUA target. RESULTS: At baseline, patients (n=211) were with mean age of 56.4 years and 95% were male. Over 2 years, anthropometric measures were largely unchanged while cholesterol and low-density lipoprotein cholesterol (LDL-C) were reduced at year 1. Anthropometric measures were associated with presence of tophi. Higher baseline WC (OR: 0.96 per cm, 95% CI: 0.93 to 0.99) decreased and high level of high-density lipoprotein cholesterol (OR: 5.1 per mmol/L, 95% CI: 1.2 to 22.1) increased the chance of sUA target achievement at year 2. High LDL-C (OR: 1.8 per mmol/L, 95% CI: 1.2 to 2.6) predicted the chance of having a gout flare during year 2. CONCLUSION: In actively treated patients with gout, anthropometric measures were largely unchanged over 2 years and lipid levels were reduced. High WC and lipid levels predicted unfavourable gout outcomes after 2 years.

Remission, response, retention and persistence to treatment with disease-modifying agents in patients with rheumatoid arthritis: a study of harmonised Swedish, Danish and Norwegian cohorts.

OBJECTIVE: Precision medicine in rheumatoid arthritis (RA) requires a good understanding of treatment outcomes and often collaborative efforts that call for data harmonisation. We aimed to describe how harmonisation across study cohorts can be achieved and investigate how the observed proportions reaching remission vary across remission criteria, study types, disease-modifying antirheumatic drugs (DMARDs) and countries, and how they relate to other treatment outcomes. METHODS: We used data from eight existing large-scale, clinical RA registers and a pragmatic trial from Sweden, Denmark and Norway. In these, we defined three types of treatment cohorts; methotrexate monotherapy (as first DMARD), tumour necrosis factor inhibitors (TNFi) (as first biological DMARD) and rituximab. We developed a harmonised study protocol defining time points during 36 months of follow-up, collected clinical visit data on treatment response, retention, persistence and six alternative definitions of remission, and investigated how these outcomes differed within and between cohorts, by treatment. RESULTS: Cohort sizes ranged from ~50 to 22 000 patients with RA. The proportions reaching each outcome varied across outcome metric, but with small to modest variations within and between cohorts, countries and treatment. Retention and persistence rates were high (>50% at 1 year), yet <33% of patients starting methotrexate or TNFi, and only 10% starting rituximab, remained on drug without other DMARDs added and achieved American Congress of Rheumatology/European Alliance of Associations for Rheumatology or Simplified Disease Activity Index remission at 1 year. CONCLUSION: Harmonisation of data from different RA data sources can be achieved without compromising internal validity or generalisability. The low proportions reaching remission, point to an unmet need for treatment optimisation in RA.

Associations between pain sensitization and measures of physical function in people with hand osteoarthritis: Results from the Nor-Hand study.

OBJECTIVE: To examine whether pain sensitization is associated with hand and lower extremity function in people with hand osteoarthritis (OA) in the Nor-Hand study. DESIGN: Pain sensitization was assessed by pressure pain thresholds (PPTs) and temporal summation (TS). Hand function was assessed by Australian/Canadian Osteoarthritis Hand Index (AUSCAN) (range: 0-36), grip strength and Moberg pick-up test, and lower extremity function was assessed by Western Ontario and McMaster Universities Osteoarthritis Index (range: 0-68), 30-s chair stand test, and 40-m walk test. We examined whether sex-standardized PPT and TS values were cross-sectionally associated with measures of physical function using linear regression analyses. Beta coefficients were presented per sex-specific standard deviation of PPT and TS. The mediating effect of pain was examined by causal-inference based mediation analysis. RESULTS: In 206 participants, higher PPTs at/near the hand, indicative of less peripheral and/or central pain sensitization, were associated with greater grip strength and better self-reported hand function (beta for PPT at finger joint on AUSCAN function: -1.41, 95% CI -2.40, -0.42). Higher PPTs at/near the hand, near the knee and at trapezius were associated with lower extremity function, although not statistically significant for all outcomes. Self-reported pain severity mediated the effect of PPT on self-reported function. TS was not associated with hand or lower extremity function. CONCLUSION: Peripheral sensitization, and possibly central sensitization, was associated with impaired function. Effects of PPTs on self-reported function were mediated by self-reported pain, whereas there might be a direct effect of sensitization or effects through other mediators on performance-based function.

Calprotectin, a sensitive marker of inflammation, is robustly assessed in plasma from patients with early or established rheumatoid arthritis by use of different laboratory methods.

Calprotectin (S100A8/S100A9, MRP8/MRP14) is a major leukocyte protein found to be more sensitive than C-Reactive Protein (CRP) and Erythrocyte Sedimentation Rate (ESR) as a marker of inflammation in patients with rheumatoid arthritis (RA). The present objective was to explore the robustness of calprotectin assessments by comparing two different laboratory methods assessing calprotectin in plasma samples from patients with early or established RA. A total of 212 patients with early RA (mean (SD) age 52(13.3) years, disease duration 0.6(0.5) years) and 177 patients with established RA (mean (SD) age 52.9(13.0) years, disease duration 10.0(8.8) years) were assessed by clinical, laboratory, and ultrasound examinations. Frozen plasma samples (-80 °C) were analysed for calprotectin levels at baseline, 1, 2, 3, 6 and 12 months by use of either enzyme-linked immunosorbent assay (ELISA) or fluoroenzyme immunoassay (FEIA). The ELISA technique used kits from Calpro AS and the FEIA technology was assessed on an automated Thermo Fisher Scientific instrument. The results showed high correlations between the two methods at baseline and during follow-up, with Spearman correlation at baseline 0.93 (p < 0.001) in the early and 0.96 (p < 0.001) in the established RA cohorts. The correlations between each of the two calprotectin assessments and clinical examinations had similar range. Calprotectin correlated well with clinical examinations, with at least as high correlations as CRP and ESR. The present study showed similar results for the two analytical methods, supporting the robustness of calprotectin analyses, and suggest calprotectin in plasma to be included in the assessments offered by clinical routine laboratories.

Comorbidities in people with hand OA and their associations with pain severity and sensitization: Data from the longitudinal Nor-Hand study.

Objective: To determine whether the comorbidity burden and co-existing comorbidities are cross-sectionally and/or longitudinally associated with pain and pain sensitization in a cohort study of people with hand OA. Design: We examined whether comorbidity burden and individual comorbidities based on the self-administered Comorbidity Index (range: 0-42) at baseline were associated with pain outcomes at baseline and 3 years follow-up. Pain outcomes included hand and overall bodily pain (range: 0-10) as well as pressure pain thresholds at the tibialis anterior muscle (kg/cm2) and temporal summation (distal radioulnar joint) as measures of central pain sensitization. We performed linear regression analyses adjusted for age, sex, body mass index, physical exercise and education. Results: We included 300 and 196 participants in cross-sectional and longitudinal analyses, respectively. Using baseline data, the burden of comorbidities was associated with greater pain in hands (beta â€‹= â€‹0.61, 95% CI 0.37, 0.85) and overall body (beta â€‹= â€‹0.60, 95% CI 0.37, 0.87). Similar strength of associations was found between comorbidity burden (baseline) and follow-up pain. Among the individual comorbidities, back pain and depression were associated with nearly one unit higher pain score in hands and overall body at both baseline and follow-up. Only back pain was related to lower pressure pain thresholds at follow up (beta â€‹= â€‹-0.24, 95% CI -0.50, -0.001). Conclusion: People with hand OA and greater comorbidity burden, co-existing back pain or depression reported greater pain severity than their counterparts, also 3 years later. These results acknowledge the relevance of accounting for comorbidities in the pain experience in people with hand OA.

Course and predictors of work productivity in gout - results from the NOR-Gout longitudinal 2-year treat-to-target study.

OBJECTIVES: In patients with gout there is a lack of longitudinal studies on the course of work productivity. We explored longitudinal changes in and predictors of work productivity over 2 years. METHODS: Patients in the NOR-Gout observational study with a recent gout flare and serum urate (sUA) >360 µmol/l attended tight-control visits during escalating urate lowering therapy according to a treat-to-target strategy. From the Work Productivity and Activity Impairment (WPAI) questionnaire, scores for work productivity and activity impairment were assessed over 2 years together with the Beliefs about Medicines Questionnaire and a variety of demographic and clinical variables. RESULTS: At baseline patients had a mean age of 56.4 years and 95% were males. WPAI scores at baseline were 5.0% work missed (absenteeism), 19.1% work impairment (presenteeism), 21.4% overall work impairment and 32.1% activity impairment. Work productivity and activity impairment improved during the first months, and remained stable at 1 and 2 years. Comorbidities were not cross-sectionally associated with WPAI scores at baseline, but predicted worse work impairment and activity impairment at year 1. The Beliefs about Medicines Questionnaire subscale with concerns about medicines at baseline independently predicted worse overall work impairment and worse activity impairment at year 1. CONCLUSIONS: In patients with gout who were intensively treated to the sUA target, work productivity and activity impairment were largely unchanged and at 1 year predicted by comorbidities and patient concerns about medication.

Ultrasound assessment of degenerative muscle sarcopenia: the University of Barcelona ultrasound scoring system for sarcopenia.

AIM: This study aimed to (1) determine the intraobserver and interobserver reliability of ultrasonographic measurement of muscle thickness (MT) and cross-sectional area (CSA) of the rectus femoris and biceps brachii, correlating these values with manual measurements on dissected cadavers and (2) develop the first semiquantitative musculoskeletal ultrasound (MSUS) scoring system of muscle morphology in sarcopenia and assess its intraobserver and interobserver reliability. In addition, the MSUS morphology score was compared with the corresponding histological images to verify concurrent validity. METHODS: Ten cryopreserved limbs of 10 cadavers aged 68-91 years were evaluated. The MSUS scoring system was based on the severity of muscle degeneration on a 3-point qualitative scale: grade 1 (normal), grade 2 (moderate changes) and grade 3 (severe changes). Reliability was assessed with intraclass correlation coefficient (ICC) for the MT and CSA and with Cohen's kappa coefficients (κ) for the MSUS scoring system. Concurrent validity was analysed with ICC. RESULTS: The results showed excellent intraobserver and interobserver reliability for both the MSUS evaluation of MT and CSA (ICC ≥0.93). The MSUS scoring system showed excellent intraobserver reliability (κ=1.0) and very good interobserver reliability (κ=0.85). There was also a high intra- and inter-observer reliability for the histological scorings (ĸ ≥0.85 and mean ĸ=0.70, respectively), as well as high reliability between the histology and MSUS scoring systems (ICC=0.92). All results were statistically significant (p≤0.001). CONCLUSION: MSUS measures of MT and CSA and the novel MSUS scoring system for degenerative muscle changes in sarcopenia was found to be reliable and strongly associated with histological findings.

Development and validation of an OMERACT ultrasound scoring system for the extent of calcium pyrophosphate crystal deposition at the joint level and patient level.

BACKGROUND: The Calcium Pyrophosphate Deposition (CPPD) subgroup of the Outcome Measures in Rheumatology (OMERACT) Ultrasound working group was established to validate ultrasound as an outcome measure instrument for CPPD, and in 2017 has developed and validated standardised definitions for elementary lesions for the detection of calcium pyrophosphate crystals in joints. The aim of this study was to develop and evaluate the reliability of a consensus-based ultrasound scoring system for CPPD extent, representing the next phase in the OMERACT methodology. METHODS: In this study the novel scoring system for CPPD was developed through a stepwise process, following an established OMERACT ultrasound methodology. Following a previous systematic review to gather available evidence on existing scoring systems for CPPD, the novel scoring system was developed through a Delphi survey based on the expert opinion of the members of the OMERACT Ultrasound working group-CPPD subgroup. The reliability of the scoring system was then tested on a web-based and patient-based exercise. Intra-reader and inter-reader reliability of the new scoring system was assessed using weighted Light's κ coefficients. FINDINGS: The four-grade semiquantitative scoring system consisted of: grade 0 (no findings consistent with CPPD), grade 1 (≤3 single spots or 1 small deposit), grade 2 (>3 single spots or >1 small deposit or ≥1 larger deposit occupying ≤50% of the structure under examination in the reference image-ie, the scanning view with the highest grade of depositions), and grade 3 (deposits that occupy more than 50% of the structure under examination in the reference image). The score should be applied to the knee (menisci and hyaline cartilage) and the triangular fibrocartilage complex of the wrist. The intra-reader and inter-reader reliabilities on static images were almost perfect (κ 0·90 [95% CI 0·79-1·00] and κ 0·84 [0·79-0·88]), and on the eight patients recruited (four [50%] female and four [50%] male) were substantial (κ 0·72 [95% CI 0·47 to 0·96] and 0·66 [0·61 to 0·71]). INTERPRETATION: This OMERACT ultrasound scoring system for CPPD was reliable on both static images and patients. The scoring system might be a valuable tool for ensuring valid and comparable results in clinical trials and could help monitor the extent of crystal deposition in patients with CPPD in clinical practice. FUNDING: The Italian Ministry of Health - Ricerca Corrente.

Predicting total knee arthroplasty from ultrasonography using machine learning.

Objective: To investigate the value of ultrasonographic data in predicting total knee replacement (TKR). Design: Data from the Musculoskeletal Pain in Ullensaker study (MUST) was linked to the Norwegian Arthroplasty Register to form a 5-7 year prospective cohort study of 630 persons (69% women, mean (SD) age 64 (8.7) years). We examined the predictive power of ultrasound (US) features, i.e. osteophytes, meniscal extrusion, synovitis in the suprapatellar recess, femoral cartilage thickness, and quality for future knee osteoarthritis (OA) surgery. We investigated 4 main settings for multivariate predictive modeling: 1) clinical predictors (age, sex, body mass index, knee injury, familial OA and workload), 2) radiographic data (assessed by the Kellgren Lawrence grade, KL) with clinical predictors, 3) US features and clinical predictors. Finally, we also considered an ensemble of models 2) and 3) and used it as our fifth model. All models were compared using the Average Precision (AP) and the Area Under Receiver Operating Characteristic Curve (AUC) metrics. Results: Clinical predictors yielded AP of 0.11 (95% confidence interval [CI] 0.05-0.23) and AUC of 0.69 (0.58-0.79). Clinical predictors with KL grade yielded AP of 0.20 (0.12-0.33) and AUC of 0.81 (0.67-0.90). The clinical variables with ultrasound yielded AP of 0.17 (0.08-0.30) and AUC of 0.79 (0.69-0.86). Conclusion: Ultrasonographic examination of the knee may provide added value to basic clinical and demographic descriptors when predicting TKR. While it does not achieve the same predictive performance as radiography, it can provide additional value to the radiographic examination.

The associations of psychological symptoms and cognitive patterns with pain and pain sensitization in people with hand osteoarthritis.

Objective: To examine whether psychological symptoms and cognitive patterns are associated with self-reported pain and pain sensitization in people with hand osteoarthritis (OA). Design: In the Nor-Hand study (n â€‹= â€‹300), people with hand OA self-reported psychological symptoms (Hospital Anxiety and Depression Scale), cognitive patterns (Pain catastrophizing Scale and Arthritis Self-Efficacy Scale) as well as their pain severity in hands, overall pain and multi-joint pain. Central pain sensitization was measured clinically by temporal summation and pressure pain threshold tests. We examined whether psychological symptoms and cognitive patterns were cross-sectionally associated with pain using linear regression. Beta coefficients (ß) per one standard deviation of the independent variable were presented. Stratified analyses were performed in cases of significant interactions (p â€‹< â€‹0.10). Results: Higher levels of anxiety, depressive symptoms and pain catastrophizing and low levels of self-efficacy were statistically significantly associated with higher levels of hand pain by Numeric Rating Scale (ߠ​= â€‹0.43, 0.48 and -0.57, respectively). Similar associations were found for overall pain, but not for measures of central pain sensitization. In stratified analyses, anxiety and depressive symptoms were more strongly related with pain in subgroups with younger age and higher comorbidity burden. Pain catastrophizing was more strongly related with pain in subgroups with younger age, overweight/obesity, higher comorbidity burden and poor sleep. Conclusion: Psychological symptoms and cognitive patterns were associated with self-reported OA pain, especially in people with younger age, overweight/obesity, higher comorbidity burden and poor sleep. No associations were found for psychological symptoms and cognitive patterns with pain sensitization.

Urate crystal deposition is associated with inflammatory markers and carotid artery pathology in patients with intercritical gout: results from the NOR-Gout study.

BACKGROUND: Gout is of unknown reason associated with cardiovascular disease. Ultrasound is sensitive for detecting crystal deposition and plasma calprotectin is a sensitive inflammatory marker. This study explores the associations between crystal deposition, inflammation and carotid artery pathology. METHOD: A cross-sectional analysis of baseline assessments from the NOR-Gout study was undertaken. Crystal deposition was assessed by ultrasound (double contour, tophi, aggregates) and dual-energy CT (DECT) and laboratory assessments included plasma calprotectin. The carotid arteries were bilaterally examined for carotid intima-media thickness (cIMT) and presence of plaques. Spearman correlations, Mann-Whitney tests and linear regression analyses were used to explore associations between crystal deposition, inflammatory markers,and carotid pathology. RESULTS: 202 patients with intercritical gout (95.5% men, mean (SD) age 56.5 (13.8) years, disease duration 7.9 (7.7) years) were included. Calprotectin was correlated with all scores of crystal deposition by ultrasound (r=0.26-0.32, p<0.001) and DECT (r=0.15, p<0.05). cIMT was correlated with sum score aggregates (r=0.18-0.22, p<0.05). Patients with large tophi had higher levels of calprotectin as well as more frequent carotid plaque (p<0.05). CONCLUSIONS: Study findings point towards crystal deposition contributing to subclinical inflammation with subsequent vascular implications. However, future longitudinal studies are needed to confirm such causal relationships.

Controversies in rheumatology: ultrasound for monitoring of RA-do we need it?

Clinical joint examination is the cornerstone for evaluation of patients with RA. However, since large discrepancies have been shown even between experienced rheumatologists in evaluation of joint inflammation, and tender joints may have limited value in reflecting inflammation, US has in recent decades been introduced in the clinical assessments of RA patients. US has high accordance with other imaging modalities and enables detection of clinically difficult pathologies and contributes to assessments of joints difficult to evaluate clinically. However, there is no general agreement on the optimal use of US in rheumatology, and the prevalence of machines as well as the level of experience differs greatly between countries. In addition, standardized use of US in treat-to-target follow-up of RA patients was found not to have any added value. Thus, how to use US in monitoring of RA patients is open for debate. The present article will discuss the pros and cons for using US in the clinical setting.

One- and 2-year flare rates after treat-to-target and tight-control therapy of gout: results from the NOR-Gout study.

OBJECTIVES: To explore the frequency and predictors of flares over 2 years during a treat-to-target strategy with urate-lowering therapy (ULT) in patients with gout. METHODS: In the treat-to-target, tight control NOR-Gout study patients started ULT with escalating doses of allopurinol. Flares were recorded over 2 years. Baseline predictors of flares during months 9-12 in year 1 and during year 2 were analyzed by multivariable logistic regression. RESULTS: Of 211 patients included (mean age 56.4 years, disease duration 7.8 years, 95% males), 81% (150/186) of patients experienced at least one gout flare during the first year and 26% (45/173) during the second year. The highest frequency of flares in the first year was seen during months 3-6 (46.8% of patients). Baseline crystal depositions detected by ultrasound and by dual-energy computed tomography (DECT) were the only variables which predicted flares both during the first period of interest at months 9-12 (OR 1.033; 95% CI 1.010-1.057, and OR 1.056; 95% CI 1.007-1.108) and also in year 2. Baseline subcutaneous tophi (OR 2.42, 95% CI 1.50-5.59) and prior use of colchicine at baseline (OR 2.48, 95% CI 1.28-4.79) were independent predictors of flares during months 9-12, whereas self-efficacy for pain was a protective predictor (OR 0.98 per unit, 95% CI 0.964-0.996). CONCLUSIONS: In patients with gout, flares remain frequent during the first year of a treat-to-target ULT strategy, especially during months 3-6, but are much less frequent during year 2. Baseline crystal depositions predict flares over 2 years, supporting ULT early during disease course. TRIAL REGISTRATION: ACTRN12618001372279.

Do patient-reported measures of disease activity in rheumatoid arthritis vary between countries? Results from a Nordic collaboration.

OBJECTIVES: To investigate whether patient-reported outcomes vary across countries and are influenced by cultural/contextual factors. Specifically, we aimed to assess inter-country differences in tender joint count (TJC), pain and patient's global health assessment (PGA), and their impact on disease activity (DAS28-CRP) in RA patients from five Nordic countries. METHODS: We collected data (baseline, 3- and 12-months) from rheumatology registers in the five countries comprising RA patients starting a first ever MTX or a first ever TNF inhibitor (TNFi). In order to assess the role of context (=country), we separately modelled TJC, pain and PGA as functions of objective variables (CRP, swollen joint count, age, sex, calendar period and disease duration) with linear models. Analyses were performed at each time point and for both treatments. We further assessed the impact of inter-country differences on DAS28-CRP. RESULTS: A total of 27 645 RA patients started MTX and 19 733 started a TNFi. Crude inter-country differences at MTX start amounted to up to 4 points (28 points scale) for TJC, 10 and 27 points (0-100 scale) for pain and PGA, respectively. Corresponding numbers at TNFi start were 3 (TJC), 27 (pain) and 24 (PGA) points. All differences were reduced at 3- and 12-months, and attenuated when adjusting for the objective variables. The variation in predicted DAS28-CRP across countries amounted to <0.5 units. CONCLUSIONS: Inter-country differences in TJC, pain and PGA are greater than expected based on differences in objective measures, but have a small clinical impact on DAS28-CRP across countries.

Inflammation and biologic therapy in patients with rheumatoid arthritis achieving versus not achieving ACR/EULAR Boolean remission in a treat-to-target study.

OBJECTIVE: To investigate limiting factors of American College of Rheumatology (ACR)/EULAR Boolean remission in rheumatoid arthritis (RA), and compare patients who fulfil the criteria to patients who only partly fulfil the criteria, with respect to imaging inflammation and biologic disease modifying anti-rheumatic drug (DMARD) usage. METHODS: Patients with DMARD-naïve RA were treated according to current recommendations in the the ARCTIC trial (Aiming for Remission in rheumatoid arthritis: a randomised trial examining the benefit of ultrasound in a Clinical TIght Control regimen). Limiting factors of reaching ACR/EULAR Boolean remission at 2 years were assessed. Imaging inflammation (ultrasound and MRI) in patients in remission was compared with patients failing to fulfil different components of the criteria. The OR of biologic therapy was calculated using logistic regression. RESULTS: Of 203 patients, 112 (55%) reached ACR/EULAR Boolean remission; 49 (24%) fulfilled three of four criteria. The main limiting factors were patient global assessment (PGA) (59%) and tender joints (22%). Imaging inflammation was not significantly different for patients in remission and patients not fulfilling the criteria due to elevated PGA and/or tender joints, but higher odds of using biologics (OR 3.63, 95% CI 1.73 to 7.61) were observed. CONCLUSIONS: PGA and tender joints were the factors most often limiting achievement of ACR/EULAR Boolean remission. The level of imaging inflammation was not elevated in these patients compared with patients in remission, but the odds of using biologic DMARDs were higher.

Associations of pain sensitisation with tender and painful joint counts in people with hand osteoarthritis: results from the Nor-Hand study.

OBJECTIVE: To examine associations of pain sensitisation with tender and painful joint counts and presence of widespread pain in people with hand osteoarthritis (OA). METHODS: Pressure pain thresholds (PPT) at a painful finger joint and the tibialis anterior muscle, and temporal summation (TS) were measured in 291 persons with hand OA. We examined whether sex-standardised PPT and TS values were associated with assessor-reported tender hand joint count, self-reported painful hand and total body joint counts and presence of widespread pain using linear and logistic regression analyses adjusted for age, sex, body mass index, education and OA severity. RESULTS: People with lower PPTs at the painful finger joint (measure of peripheral and/or central sensitisation) had more tender and painful hand joints than people with higher PPTs. PPT at tibialis anterior (measure of central sensitisation) was associated with painful total body joint count (beta=-0.82, 95% CI -1.28 to -0.35) and presence of widespread pain (OR=0.57, 95% CI 0.43 to 0.77). The associations between TS (measure of central sensitisation) and joint counts in the hands and the total body were statistically non-significant. CONCLUSION: This cross-sectional study suggested that pain sensitisation (ie, lower PPTs) was associated with joint counts and widespread pain in hand OA. This knowledge may be used for improved pain phenotyping of people with hand OA, which may contribute to better pain management through more personalised medicine. Further studies are needed to assess whether a reduction of pain sensitisation leads to a decrease in tender and painful joint counts.