The development of candidate composite disease activity and responder indices for psoriatic arthritis (GRACE project)

Objective To develop new composite disease activity indices for psoriatic arthritis (PsA). Methods Data from routine clinic visits at multiple centres were collected in a systematic manner. Data included all domains identified as important in randomised controlled trials in PsA. Decisions to change treatment were used as surrogates for high disease activity. New indices were developed by multiple linear regression (psoriatic arthritis disease...