Identification and characteristics of patients with potential difficult-to-treat psoriatic arthritis: exploratory analyses of the Greek PsA registry

To present the characteristics of patients with potential difficult-to-treat (D2T) PsA. We used data from the Greek multicentre registry of PsA patients. D2T PsA was defined as follows: patients with at least 6 months' disease duration, who have failed to at least one conventional synthetic DMARD and at least two biologic DMARDs/targeted synthetic DMARDs with a different mechanism of action and have either at least moderate disease activity (MODA) defined as DAPSA (Disease Activity index in PSoriatic Arthritis) >14, and/or are not at minimal disease activity (MDA). Demographic and clinical characteristics were compared between D2T and non-D2T PsA patients. In two sensitivity analyses, patients classified as D2T solely according to the MODA or MDA criterion were examined separately. Among 467 patients included, 77 (16.5%) were considered D2T and 390 non-D2T PsA. Compared with non-D2T, patients with D2T PsA presented more commonly with extensive psoriasis (P