Association of validated patient reported outcome measures with patients' self-reported disease status in axial spondyloarthritis

Objective: In axSpA, validated PROs are well-established in clinical trials, but it remains unclear whether they comprehensively reflect patients' discomfort and disease status. We aimed to investigate how patients' self-reported disease status does compare to validated clinical trial measures during routine clinical visits.

Methods: Data from axSpA patients' initial and last five visits were retrospectively analyzed. ASDAS, BASDAI, ASAS20, ASAS40 and ASAS partial remission were assessed at each visit and compared with patients' self-reported disease status, categorized into very good (status satisfaction), mild, severe, and very severe based on patient's self-reported opinion on the level of severity of symptoms' burden related to axSpA. The association of these PROs with patients' self-reported disease status was analyzed using mixed models.

Results: 3,120 visits over a median follow-up of 4.7 years from 557 axSpA patients were analyzed. Very good or mild self-reported disease status was reported in 98.7% and 90.9% of visits with inactive or low ASDAS, compared with 67.9% and 39.3% with high or very high ASDAS.Severe or very severe self-reported disease status was reported in 15.1% of visits with ASAS20 achievement, in 7.2% with ASAS40 achievement, and in 0.6% with achievement of ASAS partial remission, compared with 26.0% without ASAS20 achievement, 25.1% without ASAS40 achievement, and 30.1% without achievement of ASAS partial remission.

Conclusions: Patientś self-reported disease status was well captured by ASDAS and BASDAI in most clinical visits. Other investigated measures used in clinical trials failed to capture patientś self-reported disease status in a large proportion of visits.