Minimal disease activity and impact of disease in psoriatic arthritis: a Spanish cross-sectional multicenter study

BACKGROUND Patients with psoriatic arthritis (PsA) experience functional impairment and reduced quality of life, and thus patient global assessment in PsA is explained mainly by the physical, but also by the psychological, aspect of the disease. To assess the prevalence of minimal disease activity (MDA) in Spanish patients with PsA, we examined their characteristics and the association between MDA and the impact of the disease as assessed by the PsA Impact of Disease (PsAID) questionnaire. METHODS A cross-sectional multicenter study was carried out in patients who fulfilled the Classification for Psoriatic Arthritis (CASPAR) criteria with at least 1 year of disease duration, and who were treated with biological or conventional synthetic (cs) disease-modifying anti-rheumatic drugs (DMARDs) according to routine clinical practice in Spain. Patients were considered in MDA if they met at least 5/7 of the MDA criteria. The association between MDA and the recently developed PsAID questionnaire was also recorded. RESULTS Of 227 patients included, 133 (58.6%) were in the MDA state (52% with antitumor necrosis factor (anti-TNF)α monotherapy, 24% with csDMARD monotherapy, and 24% with anti-TNFα in combination with csDMARD). Using multivariate logistic regression analysis, male gender (odds ratio (OR) 2.74, p = 0.001), a sedentary lifestyle (OR 3.13, p = 0.002), familial history of PsA (OR 0.38, p = 0.036), C-reactive protein (CRP) level (OR 0.92, p = 0.010), and use of corticoids (OR 0.33, p = 0.007) were considered features related to MDA. MDA patients had a significantly lower impact of the disease according to PsAID (mean total score (SD): MDA 3.3 (3.1) vs. non-MDA 7.1 (5.2); p < 0.001). CONCLUSIONS Nearly 60% of Spanish PsA patients achieve MDA in routine clinical practice. MDA remains one of the most useful therapeutic targets for PsA since patients who reached this state also had a significantly lower impact of disease according to PsAID.