Translation and cross-cultural adaptation of the Brazilian version of the Down Syndrome Speech Intelligibility Survey.

Purpose: Translate and cross-culturally adapt the "Down Syndrome Speech Intelligibility Survey" questionnaire into Brazilian Portuguese.

Methods: The following steps were taken for cross-cultural adaptation: translation of the instrument from the source language to the target language, synthesis of the translated versions, evaluation of the synthesis by expert judges, evaluation of the instrument by the target audience, back translation, and pilot study.

Results: After the translation and synthesis of the translations, most expert judges analyzed almost all instrument items (n = 44, 97.77%) as very relevant, very feasible, and appropriate. In the analysis by the target population, parents suggested changes, improving the understanding of the instrument. The back translation revealed some inconsistencies in the translated and adapted version in relation to the original instrument's content, and the appropriate adjustments were made. The pilot study identified the need to adapt some questions, exclude one item (which had similar content to another), and include prior instructions for completion, resulting in the final instrument version.

Conclusion: The translation and cross-cultural adaptation verified the validity evidence based on the content of the Brazilian version of the Down Syndrome Speech Intelligibility Survey.