RT Journal Article SR Electronic T1 Domains to be considered for the core outcome set of axial spondyloarthritis: results from a 3-round Delphi survey JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP jrheum.210206 DO 10.3899/jrheum.210206 A1 Anne Boel A1 Victoria Navarro-Compán A1 Annelies Boonen A1 Philip Mease A1 Uta Kiltz A1 Maxime Dougados A1 Robert Landewé A1 Désirée van der Heijde YR 2021 UL http://www.jrheum.org/content/early/2021/07/25/jrheum.210206.abstract AB Objective Advances in the field of axial spondyloarthritis (axSpA) and the methodology to develop core sets made the ASAS group decide to update the ASAS-OMERACT core set. An important aspect was to ensure it will be applicable to the entire spectrum of axSpA. The first step was to define the most relevant disease domains. Methods A 3-round Delphi survey was conducted to gather opinions of 188 patients and 188 axSpA experts to define the most relevant disease domains to be included in the core set. The Delphi survey evaluated two separate research settings: 1) studies assessing symptom modifying therapies; 2) studies evaluating disease modifying therapies. Importance of domains was rated on a 1–9 Likert scale. A domain was considered for inclusion if for both stakeholder groups ≥70% of participants scored the domain as critical (7-9) and ≤15% scored it as not important (1-3) after three rounds. Results A total of 132 (70%) patients and 135 (72%) experts completed at least 1 round. After three rounds, 7 domains (pain, physical function, stiffness, disease activity, mobility, overall functioning & health, peripheral manifestations) were selected for the symptom modifying therapies setting. For the disease modifying therapies setting, 6 domains (physical function, disease activity, mobility, structural damage, extra-musculoskeletal manifestations, peripheral manifestations) were selected. All domains selected by experts were also selected by patients. Patients selected all offered domains except 'emotional function'. Conclusion This study provides the domains selected by patients and axSpA experts that should be considered for the core set for axSpA.