Cross-cultural adaptation and content validity of the Parkinson’s disease quality of life questionnaire for patients on device-aided therapy into Brazilian Portuguese

Objective: Parkinson’s disease (PD) is a chronic and progressive neurodegenerative disorder characterized by both motor and non-motor symptoms. Device-aided therapy (DAT) has emerged as a promising approach for the treatment of PD, highlighting the importance of assessing the quality of life in patients undergoing such interventions. The objective of this study was to perform the cross-cultural adaptation and evaluate the content validity of the Parkinson’s Disease Quality of Life Questionnaire for Patients on Device-Aided Therapy (PDQ-DAT) for Brazilian Portuguese. Method: This methodological study was conducted at the Medical Specialties Center of Santa Casa in Belo Horizonte, Brazil, following international guidelines for cross-cultural adaptation. The process included the following steps: initial translation, synthesis of the translations, back-translation, expert committee review, and pre-testing. The pre-final version of the instrument was administered to a sample of thirty PD patients undergoing deep brain stimulation (DBS). The content validity index (CVI) was assessed based on three criteria: clarity/comprehension, relevance/importance, and comprehensiveness. Results: The adapted version of the PDQ-DAT demonstrated satisfactory semantic, idiomatic, cultural, and conceptual equivalence. The participants (mean age: 62.7 ± 5.2 years) reported ease in understanding the items, indicating good acceptability of the instrument. All items of the PDQ-DAT-Br achieved a CVI greater than 0.9 across the three evaluated criteria, confirming excellent content validity. Conclusion: The PDQ-DAT-Br proved to be a valid and user-friendly tool for assessing the quality of life of individuals with PD undergoing DBS in the Brazilian context.