Disease features associated with a low disease impact in patients with psoriatic arthritis: results of a cross-sectional multicenter study.

Background: Patient-reported outcomes measures, such as those provided by the Psoriatic Arthritis Impact of Disease (PsAID) questionnaire, have been found to be a reliable indicator of change during treatment, predictive of long-term outcomes, and the impact of psoriatic arthritis (PsA) on patients' lives. The objective of the study was to describe the demographic and clinical characteristics of PsA patients with a low disease impact and to analyze predictive factors for that state.

Methods: Post hoc analysis of a cross-sectional multicenter study that included 223 consecutive patients. PsAID questionnaire was used to estimate disease impact. Patients with a PsAID < 4 were considered in low disease impact. Minimal disease activity (MDA) response and the Health Assessment Questionnaire (HAQ) were also assessed. The degree of agreement between the different outcomes was addressed by Cohen's kappa index.

Results: One hundred and twenty-two (54.7%) patients reached a PsAID < 4. Among them, 52.0% and 68.0% presented articular or skin remission, respectively. Almost 75% of patients were in MDA state and 85.2% presented a low disability state according to the HAQ. A moderate concordance between HAQ ≤ 0.5 and PsAID < 4 (k = 0.53), fair between MDA and PsAID < 4 (k = 0.36), and moderate between DAPSA remission and PsAID < 4 (k = 0.46) was observed. Multivariate logistic regression analysis showed that patients with distal interphalangeal joint (DIP) disease (OR 0.40, 95%CI, 0.20-0.79, p = 0.009), family history of PsA (OR 0.25, 95%CI, 0.09-0.72, p = 0.010), and higher C-reactive protein (OR 0.92, 95%CI, 0.85-0.99, p = 0.036) were significantly less likely to reach a PsAID < 4.

Conclusions: There is certain discrepancy between disease activity measures and a low impact of disease in PsA. Clinical features (DIP joint involvement), biologic activity, and genetic factors (familial history) seem to be associated with lower odds of reaching a low disease impact.