Cross-cultural adaptation to the Brazilian Portuguese language of the Waisman Activities of Daily Living (W-ADL) for adolescents and adults with developmental disabilities

Waisman Activities of Daily Living (W-ADL) is a free and brief measure of activities daily living (ADL) for adolescents and adults with developmental disabilities. However, its use is limited in non-English-speaking countries. For this reason, translation, cross-cultural adaptation, and validation for other languages are needed. Thus, this study aimed to perform a translation and cross-cultural adaptation and validation of the W-ADL from English to Portuguese language. We used a rigorous approach for translating and adapting the scale, which included a committee of six experts to assess content validity. We also conducted interviews with 62 caregivers of people with a medical diagnosis of Autism spectrum disorder (ASD) or Down syndrome (DS) with different age groups who responded about the person with ASD or DS in their care. Our results include all steps from the translation and cross-cultural adaptation process. Item Content Validity Index showed that items 5 and 16 showed values not acceptable in “relevance” and “theoretical dimension”. On the other hand, the scale content validity index indicated acceptable value. Furthermore, our results showed that our version had acceptable reliability, did not presented floor and ceiling effects, and was able to discriminate subjects from different age groups, as expected. In conclusion, the two versions of the Portuguese version of the W-ADL Scale (15 items and 17 items) demonstrated the acceptable validity and reliability measurement to evaluate ADL for adolescents and adults with developmental disabilities. However, the 15-item version seems to be the best option for Portuguese language speakers