Validation of the Japanese version of the tinnitus functional index (TFI)

Objective: The tinnitus functional index (TFI), a new self-report questionnaire, was developed for the measurement of tinnitus severity and treatment-related changes. The original English version has been translated into several languages. The aim of this study was to evaluate the reliability and validity of the Japanese version of the TFI. Design: The English version of the TFI was translated into Japanese using a translation-back translation method. Participants completed a series of questionnaires including the TFI, Tinnitus Handicap Inventory (THI), Self-rating Depression Scale, State-Trait Anxiety Inventory, Visual Analogue Scale, and the questionnaire of subjective symptom improvement. We examined internal consistency, reproducibility, convergent and discriminant validity, and effect sizes. Study sample: One hundred and forty-three patients with subjective tinnitus were included. Results: The Japanese version of the TFI had high internal consistency and reproducibility, and good convergent and discriminant validity. At six months after the start of treatment, the effect sizes for the TFI were somewhat larger than those for the THI. Conclusions: The Japanese version of the TFI is appropriate for measuring tinnitus severity and treatment-related changes. The reliability and validity of this version are comparable to those of the original English version of the TFI.