Cross cultural adaptation and validation of the Hindi version of foot function index.

BACKGROUND

The Foot Function Index (FFI) is a reliable and widely used standardized questionnaire that measures the impact of foot pathology on function. With 571 million Hindi-speaking people living globally and an increasing incidence of foot-related pathologies, it is imperative to cross-culturally translate and adapt a Hindi version of the FFI (FFI-Hi). We aimed to translate, cross-cultural adapt, and psychometrically test the FFI-Hi for use in Hindi-speaking individuals with foot conditions.

METHODS

The translation of FFI-Hi was performed according to guidelines given by MAPI Research Trust. A total of 223 Hindi-speaking participants afflicted with foot conditions completed the FFI-Hi alongside the Short Form 36 (SF-36) questionnaire. The study duration spanned between October 2023 and January 2024. The initial phase was the translation and adaptation of FFI to cultural context. Followed by testing of psychometric properties involving of 133 participants for the test-retest reliability of FFI-Hi after a 7-day interval.

RESULTS

The mean age of the participants was 47.10 (± 8.1) years. The majority of the participants were male (n = 148, 66.4%) and the most common foot condition was plantar fasciopathy (n = 91, 40.8%). The mean score of FF-Hi was 33.7 ± 11.7. The internal consistency of FFI-Hi was good with the Cronbach's alpha (α) value of 0.891 and excellent reproducibility with the intra-class correlation of 0.90. The 95% minimal detectable change (MCD) and the standard error of measurement of the FFI-Hi was 22.02 and 7.94 respectively. Convergent validity between FFI-Hi subscales and SF-36 domains was moderate. Factor analysis corroborated the multidimensional nature of the FFI-Hi.

CONCLUSION

The FFI-Hindi version was successfully cross-culturally adapted, translated and demonstrated acceptable psychometric properties to be used in clinical practice and research. Further, the context-specific Hindi language version of FFI will enhance the utility of FFI in foot function evaluation and remove language barrier in patients reporting disability and activity limitation related to foot conditions.

REGISTRATION: Clinical Trials Registry of India (CTRI/2023/07/055734).