Early identification of axial spondyloarthritis in a multi-ethnic Asian population

Introduction/objectives: To address the diagnostic delay in axial spondyloarthritis (axSpA), we have cross-culturally adapted the Hamilton axSpA questionnaire, a self-administered screening questionnaire, in the Singapore population. In this study, we compared the performance of various scoring methods for this questionnaire in detecting axSpA. Method: The questionnaire was self-administered by eligible subjects. Scoring methods included method A, the original questionnaire scoring, and methods B–E, scoring developed based on the Assessment of SpondyloArthritis International Society (ASAS) criteria for inflammatory back pain (IBP) and the referral, classification and both referral and classification of axSpA, respectively. The reference standard was diagnosis by a rheumatologist. Since the ASAS criteria-based scoring methods were mainly based on clinical axSpA features, self-report and rheumatologist-assessment of clinical axSpA features were also compared in subjects with axSpA. Results: Of 1418 subjects (age: 54 ± 14 years, female: 73%) recruited, 46 were diagnosed with axSpA by a rheumatologist. Sensitivities of methods A–E were 35%, 61%, 63%, 48% and 83%, respectively. Self-report of clinical axSpA features exceeded rheumatologist-assessment for arthritis (83 vs 26%), good response to NSAIDs (37 vs 30%), enthesitis (35 vs 30%), dactylitis (20 vs 2%) and family history for axSpA (13 vs 4%). The reverse was true for IBP (41 vs 63%) and uveitis (4 vs 15%). Conclusions: A self-administered questionnaire using the ASAS referral and classification criteria-based scoring yielded relatively high sensitivity in detecting axSpA in subjects newly referred to rheumatology clinics. This supports its evaluation as a screening and referral tool in the general population in future studies.Key Points• A self-administered questionnaire could be used as a screening and referral tool.• ASAS referral and classification criteria-based scoring yielded relatively high sensitivity.• Inaccurate perception of clinical axSpA features was observed in axSpA patients.