Disease Characteristics and the Burden of Joint and Skin Involvement Amongst People With Psoriatic Arthritis: A Population Survey

INTRODUCTION: Psoriatic arthritis (PsA) is a chronic, systemic, inflammatory disease where disease burden and quality of life (QoL) are affected by both joint and skin manifestations.

METHODS: Patient and physician reported data were collected about 3200 patients in a cross-sectional survey of patients from nine countries. Patient-reported outcomes (PROs) included perceptions of symptom importance, EuroQol questionnaire (EQ-5D), Psoriatic Arthritis Impact of Disease (PsAID12), and Work Productivity and Activity Impairment (WPAI) Index. Outcomes were compared in patients with 'joint-only' and 'joint and skin' disease symptoms.

RESULTS: Of the 3200 patients, 2703 had complete information for 'joint-only' or 'joint and skin' involvement and were included in the analysis. Patients had a mean age of 49.2 years, 45.2% were female, and 64.5% had 'joint and skin' involvement. Patients with 'joint and skin' involvement had higher mean tender and swollen joint counts (5.2 and 4.8) than patients who were 'joint-only' (2.0 and 1.5). Significantly more patients with active 'joint and skin' symptoms experienced a flare (currently or within the last 12 months) compared with 'joint-only' patients (34.9 vs. 23.2%, p < 0.001). When asked to prioritize the burden of symptoms, 61.6% of patients prioritized joints, 38.4% prioritized skin. Anxiety/depression was experienced by 41.4% of patients, 62.4% of whom indicated that both joint and skin symptoms were the cause. Patients with 'joint and skin' involvement reported significantly worse QoL, work productivity and activity impairment than 'joint-only' patients (EQ-5D index 0.79 vs. 0.85, p < 0.001; EQ-5D VAS 71.98 vs. 77.68, p < 0.001; PsAID12 2.91 vs. 1.66, p < 0.001; WPAI overall work impairment 25.61 vs. 16.32, p < 0.001).

CONCLUSIONS: PsA patients who experience 'joint and skin' symptoms had significantly worse clinical outcomes, health-related QoL, and work productivity compared with patients with 'joint-only' symptoms.