Reliability of the Animated Activity Questionnaire for assessing activity limitations of patients with hip and knee osteoarthritis

OBJECTIVE: The aim of the study was to determine the internal consistency, test-retest reliability and measurement error of the Animated Activity Questionnaire (AAQ) for assessing activity limitations in hip and knee osteoarthritis (HKOA) patients. METHODS: A total of 1,177 patients, from six countries (the Netherlands, UK, France, Denmark, Italy and Spain), completed the AAQ, a questionnaire consisting of videos displaying 17 activities with 3-5 levels of performance, from which patients choose the video that best matches their own performance. Unidimensionality was assessed by means of confirmatory factor analysis (CFA), using the following fit indices: the Tucker-Lewis index (TFI) >0.95, comparative fit index (CFI) >0.95, and root mean square error of approximation (RMSEA)