[The Voice Handicap Index: impact of the translation in French on the validation]

The aim of this prospective investigation was to validate a French version of the Voice Handicap Index (VHI). A population of 52 normal subjects and 63 patients with voice disorders replied to the questionnaire at the day of their first consultation and ten to thirty days after the consultation (before any treatment). Reproducing the methodology of the American authors, the test-retest reliability and the internal consistency reliability were measured. The validity and the sensibility related to a non dysphonic population were also analysed. Regarding the normal subjects, the maximum scores for total score and subscale scores were 20 (total), 12 (physical), 7 (functional), 6 (Emotional). These scores are statistically different when compared with pathological subjects (p < 0.00001). Test-Retest stability of the pathological subjects was found to be satisfactory for both total score and subscale scores (r > 0.87). From this data set, the critical difference scores were derived for the VHI total score (15 points), for the physical subscale (9 points) and for the functional and emotional.subscales (6 points each). As for as the internal consistency reliability, Cronbach's alpha is correct (r > 7) for the pathological subjects. Yet, the analysis of the validity reply by reply, reveals some abnormalities. In conclusion, the validity of the French translation of the VHI is confirmed but the results prompt us to improve the quality of the translation.