Abstract
Objective: The Tinnitus Functional Index (TFI) is a recent self-report instrument for tinnitus with potential advantages over other existing instruments, including a demonstrated high responsiveness. The objectives of this study were to translate and cross-culturally adapt the TFI into Swedish and to investigate its validity and reliability. Design: The development of the Swedish version (TFI-SE) followed published guidelines on cross-cultural adaptation of health questionnaires. Validity and reliability was investigated by correlating responses on the TFI-SE with other tinnitus measures [Tinnitus Handicap Inventory (THI) and visual analogue scale (VAS)] and a scale measuring anxiety and depression (HADS). Study sample: Consecutively recruited tinnitus patients (n = 100) from four Swedish clinics completed the questionnaires. The mean age of the sample was 51 years (SD =17). Results: The internal consistency of the TFI-SE was good (α = 0.95) and the test–retest reliability was high (ICC =0.93). Our results supported the eight-factor structure proposed for the original TFI, and a high correlation between the TFI-SE and the THI (r = 0.8; p < 0.01) and lower correlations between the TFI-SE and the HADS-D (r = 0.60; p < 0.01) and HADS-A (r = 0.59; p < 0.01) confirmed satisfactory convergent and discriminant validity. Conclusions: We found that the Swedish translation and cross-cultural adaptation of the TFI is valid and reliable for use with adult tinnitus patients.
Acknowledgements
We would like to thank all the people involved in the translation process, for fruitful discussions about conceptual and cultural aspects. We do also express our gratitude to all audiologists from Hörselverksamheten i Mölndal, Sahlgrenska, Skövde and Vänersborg who helped us with the data collection. Finally, we thank all patients who participated in our study. This research was supported by a grant from FoU – Habilitation and Health, Region Västra Götaland. The funding is gratefully acknowledged.
Declaration of interest: The authors declare no potential conflicts of interests with respect to the research, authorship and/or publication of this article.