OBJECTIVES: We aimed to compare various methods for imputing disease activity in longitudinally collected observational data of patients with axial spondyloarthritis (axSpA). METHODS: We conducted a simulation study on data from 8583 axSpA patients from ten European registries. Disease activity was assessed by the Axial Spondyloarthritis Disease Activity Score (ASDAS) and the corresponding low disease activity (LDA; ASDAS<2.1) state at baseline, 6 and 12 months. We focused on cross-sectional methods which impute missing values of an individual at a particular time point based on the available information from other individuals at that time point. We applied nine single and five multiple imputation methods, covering mean, regression and hot deck methods. The performance of each imputation method was evaluated via relative bias and coverage of 95% confidence intervals for the mean ASDAS and the derived proportion of patients in LDA. RESULTS: Hot deck imputation methods outperformed mean and regression methods, particularly when assessing LDA. Multiple imputation procedures provided better coverage than the corresponding single imputation ones. However, none of the evaluated methods produced unbiased estimates with adequate coverage across all time points, with performance for missing baseline data being worse than for missing follow-up data. Predictive mean and weighted predictive mean hot deck imputation procedures consistently provided results with low bias. CONCLUSIONS: This study contributes to the available methods for imputing disease activity in observational research. Hot deck imputation using predictive mean matching exhibited the highest robustness and is thus our suggested approach.

• Klíčová slova
• Axial Spondyloarthritis, Epidemiology, Interleukin-17, Tumour Necrosis Factor Inhibitors,
• MeSH
• axiální spondyloartritida * diagnóza   epidemiologie   MeSH
• dospělí MeSH
• interpretace statistických dat MeSH
• lidé MeSH
• longitudinální studie MeSH
• pozorovací studie jako téma * MeSH
• průřezové studie MeSH
• registrace MeSH
• spondylartritida diagnóza   MeSH
• stupeň závažnosti nemoci * MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Evropa epidemiologie   MeSH

BACKGROUND: Efficacy of tumour necrosis factor inhibitors (TNFi) for peripheral arthritis in patients with psoriatic arthritis (PsA) has been established in randomized clinical trials that have used improvement in summated joint counts as an outcome. Whether joints at different anatomical locations might respond differentially to TNFi remains unknown. The aim of the study was to investigate potential variations in the responsiveness to a first tumour necrosis factor inhibitor (TNFi) among joints at distinct locations in patients with psoriatic arthritis (PsA) treated in routine clinical care. METHODS: Bionaive PsA patients from nine European countries were included in this observational cohort study if ≥ 1 joint was swollen at the initiation of a first TNFi as monotherapy or added to methotrexate. Only the 28-joint count was available without imaging data confirming the presence of synovitis. The primary outcome was time to first resolution of joint swelling at each joint level. Hazard ratios (HR) for resolution comparing different joint locations were estimated using interval-censored mixed-effects Cox proportional hazards models, including a random effect for country and patient, adjusted for age and sex. RESULTS: A total of 1729 patients with 8397 swollen joints at the start of TNFi were included. Considering the upper extremity, a higher rate of resolution of joint swelling (HR, 95% CI) was observed for the shoulder (1.65, 1.16-2.35) and elbow (1.90, 1.38-2.61), while a lower rate was found for the wrist (0.72, 0.62-0.83) compared to the joints of digit 3. Within fingers, and using the same reference, joint swelling resolved fastest in digit 4 (1.77, 1.49-2.11) and digit 5 (1.88, 1.53-2.31). A lower rate of resolution of joint swelling was found for the knee in comparison to the elbow, the corresponding joint on the upper limb (0.56, 0.40-0.78). CONCLUSION: The time to resolution of joint swelling upon treatment with TNFi in patients with PsA seems to depend on the localisation of the affected joints.

• MeSH
• antirevmatika * terapeutické užití   MeSH
• dospělí MeSH
• inhibitory TNF terapeutické užití   MeSH
• kohortové studie MeSH
• lidé středního věku MeSH
• lidé MeSH
• psoriatická artritida * farmakoterapie   MeSH
• registrace * MeSH
• senioři MeSH
• TNF-alfa antagonisté a inhibitory   MeSH
• výsledek terapie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• pozorovací studie MeSH
• Geografické názvy
• Evropa epidemiologie   MeSH
• Názvy látek
• antirevmatika * MeSH
• inhibitory TNF MeSH
• TNF-alfa MeSH

OBJECTIVES: Real-world evidence is needed to inform treatment strategies for patients with PsA and axial SpA (axSpA) who have non-musculoskeletal manifestations (NMMs), various risk factors and comorbidities. International collaboration is required to ensure statistical power and to enhance generalizability. The first step forward is identifying which data are currently being collected. Across 17 registries participating in the European Spondyloarthritis Research Collaboration (EuroSpA), we aimed to map recording practices for NMMs, comorbidities and safety outcomes in patients with PsA and axSpA. METHODS: Through a survey with 4,420 questionnaire items, we explored the recording practices of 58 pre-defined conditions (i.e. NMMs, comorbidities and safety outcomes) covering 10 disease areas. In all registries we mapped for each condition whether it was recorded, the recording procedure and the potential to identify it through linkage to other national registries. RESULTS: Conditions were generally recorded at entry into the registry and clinical follow-up visits using a pre-specified list or a coding system. Most registries recorded conditions within the following disease areas: NMMs (number of registries, n = 15-16), cardiovascular diseases (n = 10-14), gastrointestinal diseases (n = 12-13), infections (n = 10-13) and death (n = 14). Nordic countries had the potential for data linkage and generally had limited recording of conditions in their registry, while other countries had comprehensive recording practices. CONCLUSION: A wide range of conditions were consistently recorded across the registries. The recording practices of many conditions and disease areas were comparable across the registries. Our findings support the potential for future collaborative research.

• Klíčová slova
• DMARDs, JAK inhibitors, biological therapies, comorbidity, multimorbidity, routinely collected data, spondyloarthritis,
• Publikační typ
• časopisecké články MeSH

OBJECTIVES: To re-evaluate cut-offs for disease activity states according to the Axial Spondyloarthritis Disease Activity Score (ASDAS), and study the impact of sex, age, calendar time, disease and symptom duration on ASDAS and ASDAS cut-offs in a large contemporary cohort. METHODS: Data from 2939 patients with axial spondyloarthritis (axSpA) starting their first tumour necrosis factor inhibitor in nine European registries were pooled and analysed. Receiver operating characteristic analyses were performed to identify cut-offs against external criteria. Six-month data including patient and physician global assessments, both ≤1 (0-10 integer scale), and Assessment of SpondyloArthritis International Society partial remission were used for separation of inactive disease (ID) from low disease activity (LDA), while patient and physician global ≤3 were applied as external criteria to separate LDA from high disease activity (HDA). Patient and physician global ≥6 were applied to separate HDA from very high disease activity in baseline data. RESULTS: The three ASDAS cut-offs identified to separate the four disease activity states in the overall patient population were <1.3, <2.0 and >3.5. Cut-offs for ID and LDA in women were higher (<1.5 and <2.0, respectively) than in men (<1.3 and <1.9), as were cut-offs in patients ≥45 years (<1.5 and <2.2) versus ≤34 years (<1.2 and <1.9) and 35-44 years (<1.3 and <1.8). Cut-offs were independent of calendar time and disease duration. CONCLUSIONS: Re-evaluation of ASDAS cut-offs for disease activity states in a large multi-national axSpA cohort resulted in cut-offs similar to those currently endorsed. Differences in cut-offs between sex and age groups for ID and LDA were observed, but the differences were minor.

• Klíčová slova
• Axial Spondyloarthritis, Disease Activity, Epidemiology,
• MeSH
• axiální spondyloartritida * diagnóza   epidemiologie   MeSH
• dospělí MeSH
• inhibitory TNF terapeutické užití   MeSH
• lidé středního věku MeSH
• lidé MeSH
• registrace * MeSH
• revmatologie normy   MeSH
• ROC křivka MeSH
• sexuální faktory MeSH
• stupeň závažnosti nemoci * MeSH
• věkové faktory MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Evropa epidemiologie   MeSH
• Názvy látek
• inhibitory TNF MeSH