POS0410 IMPACT OF SEX, AGE AND DISEASE DURATION ON ASDAS CUT-OFFS FOR DISEASE ACTIVITY STATES IN AXIAL SPONDYLOARTHRITIS - RESULTS FROM THE EuroSpA COLLABORATION
Authors: L. Midtbøll Ørnbjerg, S. Georgiadis, T. K. Kvien, B. Michelsen, S. Horskjær Rasmussen, K. Pavelka, J. Zavada, A. G. Loft, B. Glintborg, A. M. Rodrigues, M. J. Santos, D. DI Giuseppe, J. K. Wallman, A. Ciurea, M. J. Nissen, G. Kenar, Z. Rotar, K. Perdan Pirkmajer, D. Nordström, A. M. Hokkanen, B. Gudbjornsson, O. Palsson, M. Lund Hetland, M. Østergaard
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> The preferred outcome measure for assessment of disease activity in patients with axial spondyloarthritis (axSpA) is the Ankylosing Spondylitis Disease Activity Score with CRP (ASDAS). Cut-off values for the disease activity states: inactive disease (ID), low (LDA), high (HDA) and very high (VHDA) disease activity, were developed in 2011 in a cohort of 477 Norwegian patients with radiographic axSpA [1]. <h3>Objectives:</h3> To re-assess the cut-off values for disease activity states according to ASDAS in a large, multinational cohort of patients with axSpA (including both radiographic and non-radiographic axSpA) and to investigate the impact of sex, age and disease duration on these cut-offs. <h3>Methods:</h3> Data from patients with axSpA starting their first tumour necrosis factor inhibitor in routine care in nine European registries were analysed. Following the methods applied by Machado et al. [1], receiver operating characteristic (ROC) analyses were performed to select cut-off values against external criteria. Six-month follow-up data including patient and physician global assessments, both ≤1 (0-10 integer scale) and ASAS partial remission were used for separation of ID from LDA, while patient global ≤3 and physician global ≤3 were applied as external criteria to separate LDA from HDA. Patient global ≥6 and physician global ≥6 were applied to separate HDA from VHDA in baseline data. ROC analyses were performed in the entire patient population, and in cohorts stratified by sex (men and women), age (≤34, 35-44 and ≥45 years) and disease duration (≤1, 2-5 and ≥6years). <h3>Results:</h3> We included 2939 patients with available data on ASDAS and external criteria. Patients were predominantly men (61%), Human Leukocyte Antigen B27 (HLA-B27) positive (80%), with a median age of 40 years and disease duration of 3 years. Baseline disease activity was high with a median ASDAS of 3.7. The three ASDAS cut-offs identified to separate the four disease activity states in the entire patient population were 1.3, 2.0 and 3.5, respectively. Cut-offs for ID and LDA in women were higher (1.5 and 2.0) than in men (1.3 and 1.9), as were cut-offs in patients ≥45 years (1.5 and 2.2) compared to patients ≤34 years (1.2 and 1.9) and 35-44 years (1.3 and 1.8). Cut-offs were similar across disease durations (Table 1). <h3>Conclusion:</h3> Re-assessing cut-off values for ASDAS disease activity states in a large, multinational cohort of axSpA patients resulted in cut-offs largely similar to the currently endorsed cut-offs of 1.3, 2.1 and 3.5. Cut-off values between ID and LDA and between LDA and HDA, however, differed between sexes and age groups, which may be relevant for clinical decision making. <h3>REFERENCES:</h3> [1] Machado P et al. Ankylosing Spondylitis Disease Activity Score (ASDAS): Defining cut-off values for disease activity states and improvement scores. Ann Rheum Dis. 2011. <h3>Acknowledgements:</h3> The EuroSpA Research Collaboration Network was financially supported by Novartis Pharma AG. Novartis had no influence on the data collection, statistical analyses, abstract preparation or decision to submit the abstract. <h3>Disclosure of Interests:</h3> Lykke Midtbøll Ørnbjerg Research grant paid to employer from Novartis, Stylianos Georgiadis Research grant paid to employer from Novartis, Tore K. Kvien Grünenthal, Sandoz, and UCB, AbbVie, Amgen, Celltrion, Gilead, Novartis, Pfizer, Sandoz, UCB, Brigitte Michelsen Novartis, Research grant paid to employer from Novartis, Simon Horskjær Rasmussen Research grant paid to employer from Novartis, Karel Pavelka AbbVie, UCB, Pfizer, Eli Lilly, Celltrion, MSD, and Novartis, Jakub Zavada Abbvie, Elli-Lilly, Sandoz, Novartis, Egis, UCB, Sanofi, Astra Zeneca, Sobi, Anne Gitte Loft AbbVie, Janssen, Lilly, MSD, Novartis, Pfizer, UCB, AbbVie, Janssen, Lilly, MSD, Novartis, Pfizer, UCB, Bente Glintborg Research grants from Pfizer, Abbvie, BMS, Sandoz, Ana Maria Rodrigues AbbVie, Amgen, AbbVie, Amgen, Maria José Santos Abbvie, AstraZeneca, Janssen, Lilly, Medac, Novartis, Pfizer, Daniela Di Giuseppe: None declared, Johan K Wallman AbbVie, Amgen, Research support from AbbVie, Amgen, Eli Lilly, Novartis, Pfizer, Adrian Ciurea: None declared, Michael J. Nissen AbbVie, Amgen, Eli Lilly, Janssens, Novartis, Pfizer, AbbVie, Eli Lilly, Janssens, Novartis, Pfizer, Gökçe Kenar: None declared, Ziga Rotar Abbvie, Amgen, Novartis, MSD, Medis, Biogen, Eli Lilly, Pfizer, Sanofi, Lek, Janssen, Abbvie, Novartis, Eli Lilly, Pfizer, Janssen, SOBI, Swixx BioPharma, AstraZeneca, Katja Perdan Pirkmajer Abbvie, Novartis, MSD, Medis, Eli Lilly, Pfizer, Lek, Janssen, Abbvie, Novartis, Medis, Eli Lilly, Pfize, Boehringer Ingelheim, Dan Nordström Novartis, Pfizer, UCB, Abbvie, BMS, Lilly, MSD, Novartis, Pfizer, Roche, UCB, Anna-Mari Hokkanen MSD, Bjorn Gudbjornsson Novartis and Nordic-Pharma, Novartis, Olafur Palsson: None declared, Merete Lund Hetland Speaker for Pfizer, Medac, Sandoz (no personal income, institution), Advisory Board Abbvie (No personal income, paid to institution). Prev. chaired the steering committee of the Danish Rheumatology Quality Registry (DANBIO, DRQ), which receives public funding from the hospital owners and funding from pharmaceutical companies., Research grants (institution) from Abbvie, Biogen, BMS, Celltrion, Eli Lilly, Janssen Biologics B.V, Lundbeck Fonden, MSD, Medac, Pfizer, Roche, Samsung Biopies, Sandoz, Novartis, Nordforsk, Mikkel Østergaard Speaker and/or consultancy fees from Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli-Lilly, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, Sandoz, Sanofi, UCB, Abbvie, BMS, Merck, Novartis and UCB.