SAT0254 Performance of the Assessment of Spondyloarthritis International Society (ASAS) Spondyloarthritis Classification Criteria in a Clinical Cohort of Patients

Background ASAS classification criteria have been developed and validated to make an early classification of patients presenting with symptoms of spondyloarthritis (SpA), and to better distinguish between patients with predominantly axial SpA (axSpA) and predominantly peripheral SpA (pSpA). Objectives To investigate the performance of the criteria sets for SpA in a clinical cohort, according to the different available criteria sets (ASAS, ESSG, and Amor) and to assess how the ASAS classification criteria perform in daily clinical practice. Methods The cohort was established before the development of the ASAS SpA classification criteria, implying that there could not be selection towards the application of these criteria Patients with a clinical diagnosis of SpA attending a specialized rheumatology outpatient clinic were retrospectively classified. The group of patients who met all three criteria sets was compared to the group of patients who met neither. Results In total, 83.3% of the patients in the cohort (n=581) could be classified as SpA according to the ASAS criteria, 74.1% according to ESSG criteria and 53.1% according to Amor criteria (figure 1). Thirty four percent of patients had predominantly peripheral SpA. A high level of overlap between criteria sets was found and 46.8% (n= 272) of the patients fulfilled all three criteria sets. Those fulfilling the three criteria sets were older (p=0.047), had more SpA features (p=