Performance of the Assessment of Spondyloarthritis International Society criteria for the classification of spondyloarthritis in early spondyloarthritis clinics participating in the ESPERANZA programme

OBJECTIVE The objective of this study was to analyse the performance of the Assessment of SpondyloArthritis International Society (ASAS) criteria for the classification of SpA in early SpA clinics. METHODS We used a cross-sectional study of patients referred to early SpA units within the ESPERANZA programme (a Spanish nationwide health management programme designed to provide excellence in diagnosis and care for early SpA). Patients were eligible if they were