DAPSA, DAS28 and MDA predict long-term treatment regime in psoriatic arthritis. The Swedish Early Psoriatic Arthritis Cohort.

Objectives: To describe treatment patterns in the Swedish early psoriatic arthritis cohort (SwePsA) of the mono-/oligo-arthritic (M/O) and polyarthritis (P) and identify early predictive factors for treatment with disease-modifying anti-rheumatic (DMARD), non-steroidal anti-inflammatory drugs (NSAID), and tumour necrosis factor inhibition (TNFi) after 5 years.
Methods: Data for 198 M/O and P PsA were obtained within the programme for SwePsA. Multinomial and binary logistic regression analyses were used to assess the association between early predictive factors and treatment after 5 years adjusted for age at inclusion. The analysis of DMARD/NSAID was adjusted for medication at inclusion.
Results: After inclusion visit, DMARD was prescribed in 30% of M/O and 56% of P PsA; mainly methotrexate. TNFi was not prescribed at inclusion, but 23 patients were treated at 5-year follow-up. The adjusted OR (95% CI) for treatment with both DMARD and NSAID after 5 years was 3.65 (1.34 - 9.89) (p=0.010) for Disease Activity Score 28 (DAS28) >3.2 and 2.90 (1.20-6.99) (p=0.038) for Disease Activity Index in Psoriatic Arthritis (DAPSA) >14 at inclusion. TNFi treatment was, after adjusting for age, associated with high erythrocyte sedimentation rate (p=0.0043), high C-reactive protein (p=0.013), DAPSA (p<0.001), not reaching minimal disease activity (p=0.001) high health assessment questionnaire (p=0.001), patient's overall assessment on the visual analogue scale (VAS) (p=0.009), high pain VAS (p=0.007), and high number of tender and swollen joints (p=0.031) at inclusion.
Conclusions: Disease activity in early M/O and P PsA is to be considered in deciding the level of health care assessment and future pharmacological treatment. DAS28 >3.2 and DAPSA>14 early in the disease predict subsequent treatment with DMARD. For prediction of biological treatment, not reaching MDA at onset of disease, would be the composite index of choice.