title: Comparison of performance of the Assessment of SpondyloArthritis International Society, the European Spondyloarthropathy Study Group and the modified New York criteria in a cohort of Chinese patients with spondyloarthritis.
abstract: Early diagnosis of spondyloarthritis (SpA) is essential as anti-tumor necrosis factor therapy can achieve significant symptomatic relief and control of disease activity. This study aims to compare the clinical characteristics, disease activity, and functional status of a Chinese cohort of SpA patients who were re-classified into ankylosing spondylitis (AS) patients fulfilling the modified New York (MNY) criteria, those with undifferentiated SpA (USpA) fulfilling the European Spondyloarthropathy Study Group (ESSG) classification criteria only (USpA/ESSG) and those who fulfill Assessment of SpondyloArthritis International Society (ASAS) only (USpA/ASAS). Disease activity was evaluated by Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), severity of morning stiffness, patient global assessment, and C-reactive protein. Functional status was evaluated by Bath Ankylosing Spondylitis Functional Index (BASFI), modified Schober index, and dimension of chest expansion. One hundred and twenty-eight patients with disease duration of 16.3 ± 10.4 years were recruited. Patients in USpA/ESSG and USpA/ASAS were significantly younger (p = 0.01), had shorter disease duration (p < 0.01), and lower BASFI (p = 0.03) than established AS patients. All three groups have active disease with comparable BASDAI >3. BASFI correlated inversely with dimension of chest expansion and negatively modified Schober index in AS patients (p < 0.01) and modestly with BASDAI (r = 0.25, p < 0.01). BASFI correlated moderately with BASDAI in USpA/ESSG (r = 0.61, p < 0.01) but not with chest expansion or modified Schober index. Compared with established AS patients recognized by MNY criteria, patients fulfilling USpA defined by ESSG or ASAS criteria had earlier disease, as active disease and less irreversible functional deficit.
authors.affiliation: Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, SAR China.
authors.forename: Ho Yin
authors.initials: HY
authors.lastname: Chung
authors.forename: Chak Sing
authors.initials: CS
authors.lastname: Lau
authors.forename: Ka Pik
authors.initials: KP
authors.lastname: Wu
authors.forename: Woon Sing
authors.initials: WS
authors.lastname: Wong
authors.forename: Mo Yin
authors.initials: MY
authors.lastname: MOK
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D044466:Asian People; D003431:Cross-Cultural Comparison; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D042241:Early Diagnosis; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D013167:Spondylitis, Ankylosing / Q000145:classification / Q000175:diagnosis* / Q000503:physiopathology*; D016896:Treatment Outcome