Purpose of review: A number of drugs for psoriatic arthritis have been tested in randomized clinical trials, and more agents are likely to be evaluated in the future. Such studies have highlighted the relative lack of well-validated or agreed-on outcomes that should be assessed.
Recent findings: Consensus exercises have identified core domains for intervention studies in psoriatic arthritis. Many of the tools used to measure these domains have been borrowed from rheumatoid arthritis or ankylosing spondylitis, but increasing data relate to psoriatic arthritis specifically. Nonetheless, there are gaps in the measurement toolkit, particularly with respect to assessing dactylitis and axial inflammation. Further validation of functional disability instruments, radiologic scoring methods, and enthesitis instruments is also required. Currently available composite responder criteria are based principally on peripheral joint inflammation and may not be inclusive enough to represent fully the spectrum of patients with psoriatic arthritis.
Summary: There have been significant developments in robust tools for assessing outcome in psoriatic arthritis. Since October 2002, much of the activity in this area has been developed by the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis and will have culminated in the Outcomes Measures in Rheumatology Clinical Trials meeting in May 2004. Relatively little of this work has been published at the time of this review. Nevertheless, this effort will have a significant influence on the design and reporting of clinical trials in psoriatic arthritis.