Inconsistencies of the Disease Activity Assessment Tools for Psoriatic Arthritis: Challenges to Rheumatologists.

OBJECTIVE

Currently, concerning the evaluation of psoriatic arthritis (PsA), there is no agreement on a standardized composite index for disease activity that includes all relevant domains. The present study sought to assess the rates of remission (REM)/low disease activity (LDA) and disease states [minimal disease activity (MDA), very low disease activity (VLDA)] as defined by diverse activity scales (DAPSA, DAS28-ESR) in an attempt to display discrepancies across these assessment tools for peripheral PsA.

METHODS

The study involved 758 patients (496 females, 262 males; mean age 47,1 years) with peripheral PsA who were registered to the Turkish League Against Rheumatism (TLAR) Network. The patients were assessed using the DAS28-ESR, DAPSA, MDA, and VLDA. The overall yield of each scale was assessed in identifying REM and LDA. The presence or absence of swollen joints was separately analysed.

RESULTS

The median disease duration was 4 years (range 0-44 years). According to DAPSA and DAS28-ESR, REM was achieved in 6.9% and 19.5% of the patients, respectively. The rates of MDA and VLDA were 16% and 2.9%, respectively. Despite the absence of swollen joints, a significant portion of patients were not considered to be in REM (296 (39.1%) patients with DAS28-ESR, 364 (48%) with DAPSA, and 394 (52%) with VLDA).

CONCLUSION

Patients with peripheral PsA may be assigned to diverse disease activity levels when assessed with the DAS28-ESR, DAPSA, MDA and VLDA, which would inevitably have clinical implications. In patients with PsA a holistic approach seems to be necessary which includes other domains apart from joint involvement, such as skin involvement, enthesitis, spinal involvement, and patient-reported outcomes.