Validity and reliability of the French translation of the Identification of Functional Ankle Instability (IdFAI). Issue 6 (August 2022) - Beaudart, Charlotte
Highlights: The IdFAI questionnaire is a self-reported easy-to-apply patient-reported outcome tool measuring chronic ankle instability. The French IdFAI questionnaire is now available to assess chronic ankle instability both in research and clinical settings. This new version demonstrates adequate measurement properties. Abstract: Purpose: To translate and validate the Identification of Functional Ankle Instability (IdFAI) into French. Methods: The IdFAI was translated according to international recommendations. Discriminative power, floor and ceiling effects, construct validity (including confirmatory factorial analysis (CFA)), internal consistency and test-retest reliability were measured. Standard Error of Measurement (SEM) and Smallest Detectable Change (SDC) were also calculated. Results: 160 participants were included. The IdFAI-F showed a very good test-retest reliability (ICC = 0.95). The SEM was 1.37 and the MDC was 3.79. The internal consistency was moderate (Cronbach's alpha coefficient = 0.68). The correlation between the IdFAI and the Cumberland Ankle Instability Tool (CAIT) was high (r = −0.75, p < 0.001). No floor, nor ceiling effects were observed. The CFA analyses did not confirm the factor structure proposed by the authors of the original English version. Conclusions: The IdFAI-F is a valid and reliable tool to accurately identify and measure chronic ankle instability in research and clinical settings for French-speaking individuals.