Cross-cultural adaptation of the Iranian Voice Quality of Life Profile into Brazilian Portuguese.

Purpose: To cross-culturally adapt the Voice Quality of Life Profile (IVQLP) into Brazilian Portuguese (BP).

Methods: The cross-cultural adaptation process was performed in five stages: translation of the IVQLP into BP by three native BP experts fluent in American English; preparation of a consensus version; back-translation by a native American English expert fluent in BP; analysis by a committee of five experts and preparation of the final version of the instrument in BP, which was named IVQLP-Br; and pre-testing. The IVQLP-Br aims to assess the impacts of the voice more comprehensively, encompassing various areas of an individual's life. It has 43 items and a five-level response key. For the pre-test, the alternative "not applicable" was added as a response option. Thirty-six adults with self-reported risk of dysphonia participated in the pre-test.

Results: In the translation stage, ten items were modified, and during the back-translation, 15 items required adjustments. No questions required reformulation after the application of the IVQLP-Br in the target population, because the option "not applicable" appeared in 12 responses without statistical significance.

Conclusion: The version of the IVQLP translated into BP, named the IVQLP-Br, exhibited cross-cultural equivalence and was administrable for a more detailed analysis of the impact of the voice in different domains of an individual's life. After validation, the IVQLP-Br will be able to contribute both to clinical practice and to research with BP speakers.