Outcome measures in psoriatic arthritis clinical trials.

Outcome measures in psoriatic arthritis (PsA) have been primarily borrowed from the assessment of rheumatoid arthritis and ankylosing spondylitis, although several specific measures for PsA have been established. The advent of new therapeutic agents for the treatment of PsA has made the need for specific outcome measures for PsA more critical to evaluate the heterogeneous manifestations of this disease and features that are unique to its assessment. Several outcome measures have been validated for use in PsA clinical trials while others are being evaluated by groups such as The Group for Assessment of Psoriasis and Psoriatic Arthritis for future use in clinical trials.