Linguistic Validation of the Phenylketonuria - Quality of Life (PKU-QOL) Questionnaire Into Brazilian Portuguese

Abstract The phenylketonuria - quality of life (PKU-QOL) questionnaire was developed to assess the impact of phenylketonuria (PKU) and its treatment on the health-related quality of life (HRQL) of patients and their caregivers. Available in four versions (child, adolescent, adult and parent), it was developed and validated in eight countries. The objective of this study was to linguistically validate the PKU-QOL questionnaire in Brazilian Portuguese for use in Brazil by clinicians who take care of PKU patients. The translation method used a standard linguistic validation process. The British English version served as a basis for translation. No major cultural or semantic issues were found during the process. The main difficulty was the use of the acronym “PKU” in the first translations. During the cognitive interviews, respondents made the confusion between the disease itself and the food supplement since it is written “PKU” or “COMIDA-PKU” on the packaging of the product. To overcome this issue, it was decided to use fenilcetonuria (fenil) or fenil alone throughout all versions. The PKU-QOL will be valuable for Brazilian healthcare providers in individualizing treatment and managing patients with PKU.