RT Journal Article SR Electronic T1 Metric Properties of the SPARCC Score of the Sacroiliac Joints — Data from Baseline, 3-month, and 12-month Followup in the SPACE Cohort JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP jrheum.140806 DO 10.3899/jrheum.140806 A1 Rosaline van den Berg A1 Manouk de Hooge A1 Pauline A.C. Bakker A1 Floris van Gaalen A1 Victoria Navarro-Compán A1 Karen Minde Fagerli A1 Robert Landewé A1 Maikel van Oosterhout A1 Roberta Ramonda A1 Monique Reijnierse A1 Désirée van der Heijde YR 2015 UL http://www.jrheum.org/content/early/2015/04/27/jrheum.140806.abstract AB Objective To evaluate metric properties of the SpondyloArthritis Research Consortium of Canada (SPARCC) score of the sacroiliac (SI) joints. Methods Patients with back pain (≥ 3 months, ≤ 2 years, onset < 45 years) were included in the SPACE cohort (SpondyloArthritis Caught Early). Patients with (possible) axial spondyloarthritis had followup visits after 3 and 12 months and were treated according to clinical practice. Magnetic resonance imaging (MRI) of the SI joints (MRI-SI) was scored in 2 independent campaigns (campaign 1: at baseline and 3 months; campaign 2: at baseline, 3 months, and 12 months) by 2 different blinded reader pairs, applying the Assessment of Spondyloarthritis International Society (ASAS) definition (MRI-SI+ vs MRI-SI–; discordant cases were adjudicated by a third reader) and SPARCC score (mean of 2 agreeing readers). Calculations were made for agreement between SPARCC score cutoff values and a consensus judgment of MRI-SI+ (ASAS definition) as external standard, change in SPARCC score, and smallest detectable changes (SDC) over 3 and 12 months. Results SPARCC score ≥ 2 showed best agreement with MRI-SI+ in both campaigns. Regarding observed changes in relation to SDC, SPARCC score changed in 70/151 patients; 26/70 patients changed > SDC (3.4), of whom 20 patients received stable treatment over 3 months in campaign 1. Over 3 months, 20/68 patients showed changes in SPARCC score; 11/20 > SDC (2.1), of whom 8 patients received stable treatment. Over 1 year, 23/74 patients changed their SPARCC score; 14/23 changed > SDC (2.4), of whom 7 received stable treatment in campaign 2. Conclusion SPARCC score ≥ 2 can be used as surrogate for a consensus judgment of MRI-SI+ (ASAS definition) in clinical trials. The SDC ranged from 2.1–3.4 dependent on reader pair and were close to the proposed minimum important change of 2.5.