Performance and Predictors of Minimal Disease Activity Response in Patients With Peripheral Spondyloarthritis Treated With Adalimumab

Objective To examine the concurrent validity and discrimination of criteria for modified minimal disease activity (MDA) in peripheral spondyloarthritis (SpA) following filter principles of Outcome Measures in Rheumatology (OMERACT) and to determine predictors of modified MDA response. Methods Four modified MDA versions were derived in the ABILITY‐2 study using the Spondyloarthritis Research Consortium of Canada (SPARCC) enthesitis index or the Leeds Enthesitis Index (LEI) while excluding psoriasis. To assess concurrent validity, modified MDA versions were correlated with Peripheral Spondyloarthritis Response Criteria (PSpARC) remission, Ankylosing Spondylitis Disease Activity Score showing inactive disease (ASDAS ID), and physician global assessment of disease activity. Treatment discrimination was assessed between adalimumab and placebo at week 12. Multiple logistic regression was used to determine baseline predictors of long‐term modified MDA responses and sustained modified MDA. Results The 4 modified MDA versions showed a stronger positive correlation with PSpARC remission (rtet > 0.95) versus ASDAS ID (rtet > 0.75) at week 12 and years 1–3 and were able to show discrimination (P