Disease burden measured by patient-reported outcomes: does psoriatic arthritis feel worse than rheumatoid arthritis? A cross-sectional nationwide study.

OBJECTIVES: To study the subjective disease burden of patients with psoriatic arthritis (PsA) and rheumatoid arthritis (RA), using patient-reported outcomes (PROs) cross-sectionally. METHODS: Data of 3598 patients with PsA and 13913 with RA were extracted from the database. Measures included the VAS-values of pain, fatigue and patient global assessment (PGA), HAQ, and disease activity at the most recent visit/remote contact in the period 1.2020 to 9.2021. Values were compared between patients with PsA and RA overall, and by sex and age (<50, 50-59, 60-69 and ≥70 years). Regression analyses were applied. RESULTS: The overall median (IQR)-values for pain were 29 (10, 56) for PsA and 26 (10, 51) for RA, 29 (9, 60) and 28 (8, 54) for fatigue, 28 (10, 52) and 29 (11, 51) for PGA, 0.4 (0, 0.9) and 0.5 (0, 1.0) for HAQ (p<0.001 for all comparisons; adjusted for sex and age). The median (IQR)-values for pain, fatigue, PGA and HAQ were higher for PsA vs. RA in most age groups for males and females. All PROs were higher in older patients with both diagnoses. The median values for DAS28, doctor global assessment, ESR and CRP were 1.9 vs. 2.0, 8 vs. 8, 7 vs. 8 and 2 vs. 3 in PsA and RA, respectively. CONCLUSIONS: Overall, both PsA and RA groups showed moderate disease control by patients' perspective, but the burden of disease was higher especially in women with PsA compared to RA. Disease activity was similar and low in both diseases.