Reliability and Validity of the Persian Version of the Foot Function Index in Patients with Foot Disorders

Background: Foot function index (FFI) is a worthy subjective patient reported outcome measures (PROM) tool for evaluation of the outcomes of medical interventions on foot and ankle. This study was conducted to assess the validity of the Persian version of the foot function index (FFI). Methods: After translating the original FFI into Persian, back-translation was performed on the agreed Persian version and the final version was established. A total of 113 Persian-speaking patients with foot and ankle problems were enrolled in this study and were asked to fill in the FFI. Results: The Cronbach's alpha for subsections of FFI and MOXFQ was above 0.8 and 0.7, respectively, while it was 0.95 and 0.93 for total FFI and MOXFQ, respectively. The ICC for all subsections of MOXFQ and FFI was above 0.7. The Pearson's correlation coefficient for all subsections of FFI and MOXFQ was significant (P<0.01). Conclusion: The Persian version of FFI is valid and reproducible in Persian speaking population.