A meeting was convened by the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) and Outcome Measures in Rheumatology (OMERACT) to further the development of consensus among physicians and patients regarding composite disease activity measures and targets in psoriatic arthritis (PsA).
Prior to the meeting, physicians and patients completed surveys on outcome measures. A consensus meeting of 26 rheumatologists, dermatologists, and patient research partners reviewed evidence on composite measures and potential treatment targets plus results of the surveys. The meeting consisted of plenary presentations, breakout sessions, and group discussions. International experts including members of GRAPPA and OMERACT were invited to the meeting, including the developers of all of the measures discussed. After discussions, participants voted on proposals for use, and consensus was established in a second survey.
Survey results from 128 health care professionals and 139 patients were analyzed alongside a systematic literature review summarizing evidence. A weighted vote was cast for composite measures. For randomized controlled trials, the most popular measures were the PsA disease activity score (40 votes) and the GRAPPA composite index (28 votes). For clinical practice, the most popular measures were an average of scores on 3 visual analog scales (45 votes) and the disease activity in PsA score (26 votes). After discussion, there was no consensus on a composite measure. The group agreed that several composite measures could be used and that future studies should allow further validation and comparison. The group unanimously agreed that remission should be the ideal target, with minimal disease activity (MDA)/low disease activity as a feasible alternative. The target should include assessment of musculoskeletal disease, skin disease, and health-related quality of life. The group recommended a treatment target of very low disease activity (VLDA) or MDA.
Consensus was not reached on a continuous measure of disease activity. In the interim, the group recommended several composites. Consensus was reached on a treatment target of VLDA/MDA. An extensive research agenda was composed and recommends that data on all PsA clinical domains be collected in ongoing studies.