Item reduction of the voice handicap index based on the original version and on European translations

Constructing an internationally applicable short-scale of the Voice Handicap Index (VHI).

Subjects were 1,052 patients with 5 different types of voice disorder groups from Belgium, France, Sweden, Germany, Italy, The Netherlands, Portugal, and the USA. Different 9- and 12-item subsets were selected from the 30 VHI items using (1) the first factor of an unrotated factor analysis (narrow range subsets) and (2) the first three factors after promax rotation (broad range subsets). Country-specific subsets were selected to test deviations from the international subsets. For all subsets, reliability was investigated using Cronbach's alphas and correlations with the total VHI. Validity was investigated using regression on voice disorder groups. All analyses were performed for the total and for all country-specific subject samples.

Reliability was high for all item subsets. It was lower for the international compared to the country-specific subsets and for the broad range compared to the narrow range subsets. Validity was best for the broad range subsets. Validity was better for the international than for the country-specific subsets. For all statistics the 12-item subsets were not essentially better than the 9-item subsets.

The international broad range 9-item subset forms a scale which approximates well the total VHI.