Foot and ankle ability measure to measure functional limitations in patients with foot and ankle disorders: a Chinese cross-cultural adaptation and validation

Purpose: To perform a cultural adaptation and validation study (internal and external) of the FAAM questionnaire to create the Chinese version of the questionnaire (FAAM-Ch). Materials and methods: Two independent professional native translators performed a translation from English to Chinese and reverse translation. Psychometric properties analysis: Internal consistency of measure was analysed through the Cronbach's coefficients. After extraction by maximum likelihood (EML), the structure factor and construct validity was analysed; to extract a factor, it was necessary to complete the following three requirements:10% of variance, Eigenvalue >1.0 and scree plot inflection point. Standard error measurement (SEM) and minimal detectable change 90 (MDC90) were calculated. FFI-Taiwan version, SF12v2, and EuroQol5D were used for criterion validity analysis. Results: The internal consistency (Cronbach's ) for specific FAAM-Ch subscales was 0.879 (ADL) and 0.901 (Sport); test-retest analysis (interclass correlation) item ranging between 0.758 and 0.970 (ADL: 0758-0946; Sport: 0.911-0.970). Measures error: 3.449% (MDC90) and 1.478% (SEM). Chi-squared value=15228.74 and gl 406) (p<0.001) and the Kaiser-Meyer-Oklin values (0.919). The correlation level with the FFI is strong, with SF12v2 is between poor and strong and with EuroQoL5d is between moderate and strong Conclusions: FAAM-Chinese version has satisfactory "transversal" psychometric properties, facilitating the inclusion of FAAM-Chinese into research and clinical practice.