A Move Toward Precision: Innovations in Measuring Spinal Mobility in Axial Spondyloarthritis.

The efficacy of therapeutic interventions in axial spondyloarthritis (axSpA), including its more severe subset of ankylosing spondylitis (AS), is measured primarily using variables that reflect inflammatory activity. Most clinical trials have relied on the Assessment of Spondyloarthritis international Society 20 (ASAS20) or ASAS40 response as primary endpoints, whereas the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and particularly the Ankylosing Spondylitis Disease Activity Score, have proven useful for monitoring disease activity longitudinally. 1,2 .