Comparison of Different Remission and Low Disease Definitions in Psoriatic Arthritis and Evaluation of Their Prognostic Value.

OBJECTIVE: There is no agreement on the optimal definitions for assessing disease state in patients with psoriatic arthritis (PsA), and some of the commonly used definitions do not include assessment of skin lesions. We investigated the performance of various definitions in patients with PsA and psoriasis. METHODS: This was a posthoc analysis of data from the PRESTA study. The remission definitions analyzed were very low disease activity (VLDA) index, defined as 7/7 of the minimal disease activity (MDA) cutoffs; Disease Activity Index for PsA (DAPSA); and clinical (c-) DAPSA. The low disease activity (LDA) definitions analyzed were as follows: MDA defined as 5/7 cutoffs; MDA joint with both the tender joint count (TJC) and swollen joint count (SJC) cutoffs mandated; MDA skin where skin cutoff was mandated; MDA joint + skin where TJC, SJC, and skin cutoffs were mandated; DAPSA LDA; and cDAPSA LDA. RESULTS: At Week 24, the proportions of patients achieving VLDA, DAPSA, and cDAPSA remission were 10%, 35%, and 37%, respectively. Of the patients achieving DAPSA and cDAPSA remission, 55% and 56%, respectively, had Psoriasis Area and Severity Index > 1. The proportions of patients achieving MDA 5/7, MDA skin, MDA joint, and MDA joint + skin were 44%, 19%, 36%, and 14%, respectively, versus 70% achieving DAPSA and cDAPSA LDA. Notable residual levels of psoriasis were observed in patients achieving the definitions that did not require skin disease control. CONCLUSION: VLDA and MDA definitions are more stringent than DAPSA and cDAPSA definitions for the assessment of PsA. The relevance of residual disease to patients, however, remains to be determined. [Clinical Trial registration: ClinicalTrials.gov NCT00245960].