Evolution of the axial spondyloarthritis disease activity score and uptake in clinical practice

This review outlines the development of the axial spondyloarthritis disease activity score (ASDAS) as a composite index to assess disease activity in axial spondyloarthritis (axSpA) and guide treatment decisions. Our review describes the iterative process by which the ASDAS was validated and its cut off values and improvement scores developed. We compare the ASDAS to the Bath ankylosing spondylitis disease activity index (BASDAI) as a tool for measuring disease activity in axSpA and how its better measurement properties have led to its widespread use in clinical and research settings.

Recent international guidelines have recommended the use of the ASDAS as a tool for measuring and monitoring disease activity. ASAS has changed the nomenclature so that ASDAS is based on CRP values whereas ASDAS-ESR retains its original meaning. The BASDAI can be employed as an alternative tool when using the ASDAS is not possible. The ASDAS now forms an important outcome measure in clinical trials and aiming for ASDAS remission has been shown to retard radiographic progression in axSpA.

The ASDAS demonstrates improved measurement properties, including greater validity and sensitivity to change, compared to single item variables. It offers a unified metric that enables healthcare professionals to collaborate and communicate more effectively about disease activity and treatment response to interventions in axSpA.