Initial assessment of the early arthritis for psoriatic patients diagnostic questionnaire in dermatology clinics in Australia, Korea and China.

OBJECTIVES:To conduct initial assessment of the early arthritis for psoriatic patients (EARP) questionnaire for Australian, Korean and Chinese populations using translated and linguistically validated versions. To measure the proportion of patients with psoriatic arthritis (PsA) among patients with psoriasis who attended dermatology clinics. METHODS:Questionnaires were translated and culturally validated into Australian English, Korean and Chinese. A multicenter, observational, descriptive estimate of the proportion of patients with PsA among patients with psoriasis attending dermatology clinics in Australia, Korea and China was conducted. Initial assessments included evaluations of floor and ceiling effects, internal consistency (using Cronbach's alpha), test-retest reliability (using intraclass coefficient), and correlations between EARP score and rheumatology findings. If the initial EARP score was ≥3, patients were assessed by a rheumatologist for PsA within 3 months of their retest questionnaire. RESULTS:Two hundred and fifty patients participated. Translated EARP questionnaires showed satisfactory internal consistency and test-retest reliability. A potential floor effect was observed for the Chinese and Korean versions. Cronbach's alpha was 0.885 (Australian), 0.776 (Korean) and 0.789 (Chinese), indicating acceptable internal consistency. Intraclass correlation coefficients were 0.89 (Australian), 0.86 (Korean) and 0.87 (Chinese), indicating acceptable test-retest reliability. EARP summary scores had weak to moderate linear correlation with the relevant PsA assessments. Overall, 32 (12.8%) patients were diagnosed with PsA based on Classification for Psoriatic Arthritis (CASPAR) score. CONCLUSION:The Australian, Korean, and Chinese versions of the EARP questionnaire are suitable for the early detection of PsA symptoms in patients with psoriasis by dermatologists working in specialist dermatology clinics. TRIAL REGISTRATION:NCT02470481.