Treatment Goals in Psoriatic Arthritis

Psoriatic arthritis (PsA) is a heterogeneous autoimmune disease that occurs in one in three people with the skin disease psoriasis. PsA can cause arthritis (joint inflammation), enthesitis (tendon and ligament inflammation), sausage digits (swollen entire finger or toe), spondyloarthritis (spinal inflammation). Skin involvement by psoriasis is also highly variable in terms of psoriasis type and location. Through combined skin and musculoskeletal involvement, psoriatic disease has a significant life impact with decrease quality of life including uncomfortable symptoms, ability to participate in life and functioning. Medications used to treat PsA have sometimes an uneven effect on the various PsA manifestations where some are more effective for skin while others more effective for the joints. In this context, clinical care and treatment of PsA is a complex process which balances disease activity with medication risks and benefits as well as patient priorities. Professional PsA treatments guidelines state that PsA treatment goals are disease remission or low disease activity. Several studies to date have shown that physicians tend to overestimate remission and low disease activity in PsA patients when compared to disease activity indices. Also patients and physicians frequently do not align on perceptions of remission or low disease activity. In the proposed study the investigators aim to identify predictors of successful treatment from a patient perspective on a range of disease measures including psoriasis, arthritis, enthesitis, dactylitis, patient reported outcomes, and laboratory assessments which are routinely collected in the clinical care of PsA. Secondary endpoints are to quantify longitudinally how stable a state of treatment success is from a patient perspective, and to define score ranges for disease measurements, including health-related quality of life measures, that correspond to treatment success from a patient perspective. The impact of this research is that the investigators will be able to define parameters predictive of achieving treatment success from a patient perspective, which will then inform goals of care for psoriatic arthritis.