Analysis of the psychometric properties of the American Orthopaedic Foot and Ankle Society Score (AOFAS) in rheumatoid arthritis patients: application of the Rasch model.

OBJECTIVE: To tested the reliability and validity of Aofas in a sample of rheumatoid arthritis patients. METHODS: The scale was applicable to rheumatoid arthritis patients, twice by the interviewer 1 and once by the interviewer 2. The Aofas was subjected to test-retest reliability analysis (with 20 Rheumatoid arthritis subjects). The psychometric properties were investigated using Rasch analysis on 33 Rheumatoid arthritis patients. RESULTS: Intra-Class Correlation Coefficient (ICC) were (0.90