Development of a Disease Severity and Responder Index for Psoriatic Arthritis (PsA) — Report of the OMERACT 10 PsA Special Interest Group

Abstract

Work within the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) to develop and validate composite disease activity measures in PsA has progressed. At the Outcome Measures in Rheumatology Clinical Trials (OMERACT) 8 meeting, a core set of domains to be assessed in randomized controlled trials (RCT) and longitudinal observational studies (LOS) of PsA was agreed upon. At OMERACT 10, work to date regarding proposed composite responder indices was presented. Five proposed composite responder definitions for PsA were reviewed and discussed including new data from the GRACE (GRAppa Composite Exercise) study. There was agreement that the work to date was promising, and that developing composite outcome measures for use in RCT and LOS was important. Further work was required, including data on followup timepoints and less common phenotypes of PsA, to ensure that all subgroups were represented within GRACE. During discussion on the concept of composite measures for PsA, based on predominant/little/no involvement in several domains (such as skin versus joints, enthesitis, dactylitis, spondyloarthritis) it was acknowledged that a simple summative score encompassing all domains of PsA would be difficult to construct psychometrically and may not be appropriate. Ideally, any composite measure should retain the ability to differentiate between activity in individual domains, such as enthesitis or skin psoriasis, so that the influence of each can be assessed independently. Further work is required within the GRACE dataset to develop an optimal composite measure for PsA. Several proposals to date have shown preliminary validity according to the OMERACT filter.

Active peripheral inflammation is associated with pro-atherogenic lipid profile in psoriatic arthritis

“…Importantly, CDAI strongly correlates with a number of other PsA activity measures, including Composite Psoriatic Disease Activity Index (CPDAI), Psoriatic Arthritis Screening and Evaluation (PASE), Disease Activity Index for Psoriatic Arthritis (DAPSA), Disease Activity Score in 28 Joints (DAS28), Simplified Disease Activity Index (SDAI) (8). We also included the presence of dactylitis and/or enthesitis because both of these features are considered to be important clinical measures in PsA (9,10), and because dactylitis is associated with radiological evidence of joint erosions in PsA (6,9,10). Low peripheral disease activity was defined as CDAI ≤10 without enthesitis or dactylitis.…”

Disease Activity in Psoriatic Arthritis: Comparison of the Discriminative Capacity and Construct Validity of Six Composite Indices in a Real World

“…Over the last few years different tools to be used for measuring the disease activity in patients with PsA have been identified by the International Group for Research in Psoriasis and Psoriatic Arthritis (GRAPPA) and the Outcome Measures in Rheumatology Clinical Trials (OMERACT) [12]. Preliminary work has been undertaken in developing a more comprehensive disease activity instrument for psoriatic disease [12, 13].…”

“…Preliminary work has been undertaken in developing a more comprehensive disease activity instrument for psoriatic disease [12, 13]. The GRAPPA recently proposed the Composite Psoriatic Disease Activity Index (CPDAI) which classifies the PsA into mild, moderate, and severe taking into account the assessment of different domains such as peripheral arthritis, skin disease, spinal disease, enthesitis, and dactylitis [14].…”

Pain in systemic inflammatory rheumatic diseases

“…Disease activity indices are often used in patients with SpA [75,76], and there is a good correlation between self-reported indices (including the Bath Ankylosing Spondylitis Disease Activity Index, BASDAI) [77] and the presence of CWP or FM, which suggests that the CWP frequently reported by women with inflammatory rheumatic diseases may also be frequent in women with axial SpA. This can cause diagnostic delays and may also partially explain why women's self-reported functional limitations are worse than those of men at any given level of radiographic damage.…”