Validation of the Danish version of the Tinnitus Functional Index

INTRODUCTION. Consensus about which questionnaire to use is necessary when it comes to evaluation of tinnitus. In Denmark, the Tinnitus Handicap Index is currently used. However, for evaluating treatment-related outcomes, the Tinnitus Functional Index (TFI) has been optimised for this and is being used in several countries. In this study, we aimed to provide validation of a professionally translated Danish version of the TFI to safely implement this questionnaire in clinical and scientific settings.METHODS. At the Department of Audiology at Hospital West Jutland, Denmark, 133 adult patients suffering from tinnitus with or without hearing loss completed the Danish version of the TFI questionnaire (TFI-Da). Internal consistency was evaluated by Cronbach's alpha and test-retest reliability with Pearson's correlation.RESULTS. Internal consistency was calculated for the total TFI score producing an excellent Crohnbach's alpha of 0.96. Crohnbach's alpha scores were also acceptable for all subgroups with values > 0.7. The test-retest reliability in terms of Pearson's correlation coefficient was 0.848 for the total TFI scores and was acceptable for all subgroups. CONCLUSION. Our study showed a very high internal consistency and test-retest reliability when using the Danish version of the TFI questionnaire. Therefore, we recommend TFI-Da as the standard questionnaire for tinnitus patients in Denmark, especially for evaluation of treatment impact.