Measuring Disease Activity and Outcomes in Early Psoriatic Arthritis

Psoriatic Arthritis (PsA) is a heterogeneous disease, characterized by manifestations of peripheral arthritis, dactylitis, enthesitis, spondylitis, and psoriasis. Patients with PsA experience the impact of disease as loss of functional ability, decreased health-related quality of life (HRQOL) and loss of productivity. Treatment is aimed at preventing these consequences. It is recommended that treatment is given as early as possible, with all manifestations taken into account, and in a treat-to-target strategy. In a treat-to-target strategy, treatment is intensified if a certain target – a composite disease activity measure – has not been achieved. Good measures of disease activity are needed to improve outcomes for patients with PsA. For this purpose, more information is needed on disease activity and outcomes early in the disease course. These are studied in the Dutch southwest Early Psoriatic Arthritis cohoRt (DEPAR) and related sub-studies.
This thesis aims to investigate the following four aspects of disease activity and outcomes in early PsA: ultrasound abnormalities of the entheses, burden of disease at time of diagnosis and its relation with disease manifestations, the relation between time to minimal disease activity and outcomes, and the performance of disease activity measures.