The ASAS core set for the assessment of axial spondyloarthritis in clinical practice

To develop the Assessment of SpondyloArthritis international Society (ASAS) core set for the assessment of axial spondyloarthritis (axSpA) in clinical practice. This entails defining an internationally endorsed and clinically feasible guiding set of domains and corresponding instruments that considers both the assessment scenarios of 'routine' and 'extended' outpatient visits.

A scoping literature review and Delphi survey among stakeholders (ASAS members, non-ASAS member rheumatologists, and patients) informed the selection of clinically relevant domains and instruments for the core set. The selected domains and instruments were presented and discussed with the ASAS community at the 2026 ASAS annual meeting, and voted upon for endorsement.

Following discussion with the ASAS community, the core set was endorsed by a majority of ASAS members. Five domains are included for routine visits: 'disease activity', 'pain', 'peripheral manifestations', 'extra-musculoskeletal manifestations', and 'treatment aspects', with 1 instrument recommended for each domain, alongside several optional instruments. Four supplementary domains are included for extended visits (to be assessed in addition to all routine visit domains): 'structural damage', 'overall functioning and health', 'comorbidities', and 'mobility', with at least 1 recommended or optional instrument incorporated for each domain.

The ASAS core set for the assessment of axSpA in clinical practice represents the minimum domains to be systematically assessed in all patients during routine and extended visits, with corresponding instruments. Its development marks a step towards improved standardisation of disease assessments in axSpA in the clinical setting, providing a practical framework that aligns with existing management recommendations.