Abstract
BACKGROUND: The International Physical Activity Questionnaire (IPAQ) is widely used to assess physical activity (PA), but its validity compared to device-measured PA data in patients with Femoroacetabular Impingement Syndrome (FAIS) and Acetabular Dysplasia (AD) remains underexplored. We evaluated the convergent and divergent aspects of construct validity of self-reported PA via the IPAQ versus accelerometry data in patients with pre-arthritic hip diseases (FAIS, AD). METHODS: Participants with FAIS or AD, aged 18 and older, completed the IPAQ and wore accelerometers for 7 days. We compared IPAQ-reported moderate-to-vigorous physical activity (MVPA) with accelerometer-measured sedentary behavior, light PA, and MVPA using Pearson correlations and Bland-Altman plots. RESULTS: Fifty-four individuals with FAIS or AD participated. We did not find any significant correlations between IPAQ-MVPA and accelerometer-measured PA variables. Bland-Altman plots revealed a positive systematic bias between IPAQ-MVPA scores and accelerometer-measured MVPA. CONCLUSIONS: The IPAQ-MVPA scores showed divergent validity compared to accelerometer data in individuals with FAIS and AD. Future studies should integrate both self-report and device-based measures to enhance accuracy.