RT Journal Article SR Electronic T1 Novel Composite Radiographic Score for Longitudinal Observational Studies of Psoriatic Arthritis: A Proof-of-concept Study JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP 1568 OP 1568 DO 10.3899/jrheum.150114.C1 VO 44 IS 10 YR 2017 UL http://www.jrheum.org/content/44/10/1568.abstract AB