Cross-cultural adaption and translation of the voice handicap index into Norwegian.

Aims: To examine the psychometric properties of a Norwegian translation of the Voice Handicap Index (VHI) and test its ability to discriminate between patients and controls. Abbreviated versions of VHI were also studied.

Method: Following standard translation, 126 healthy subjects and 126 patients with laryngeal disease answered the Norwegian translation of the VHI-30 [hereafter, VHI-30(N)].

Results: The VHI(N) showed a high Cronbach α. Control/patient scores were as follows: Emotional (E): 0.88/0.90; Functional (F): 0.77/0.91; Physical (P): 0.86/0.83, and total: 0.93/0.94. One three-level question where the subjects rated the level of voice disease correlated well with the VHI(N) scores. The 90th (95th) percentile of the control score was 18 (33), whereas the mean ± SEM patient score was 52.3 ± 2.04 of a maximum of 120 points. Differences between patient and control groups were significant for all questions on the VHI(N). Receiver operating characteristic analyses demonstrate that the F, P, E and total VHI scores discriminated very well between patients and controls. This was also the case when the abbreviated scales were analyzed as published by Nawka et al. [Folia Phoniatr Logop 2009;61:37-48] and Rosen et al. [Laryngoscope 2004;114:1549-1556].

Conclusion: This Norwegian version of the VHI questionnaire seems to be psychometrically sound.