German translation of the Characterizing Freezing of gait questionnaire: implementation of the TRAPD process

Freezing of Gait (FOG) is a severe symptom of Parkinson’s Disease (PD) that affects mobility and quality of life. The ‘Characterizing Freezing of Gait Questionnaire’ (C-FOG) is an assessment tool for screening and determining subtypes of FOG. However, it currently only exists in the English language. This study aimed to translate the C-FOG from English to German This project was conducted from September 2024 to February 2025 at a University of Applied Sciences in Krems, Austria and applied the Translation, Review, Adjudication, Pretest, and Documentation (TRAPD) process. This included professional translations, 1 review-workshop with 4 participants, adjudication, pre-testing in 2 workshops with 11 participants, including 8 healthcare workers and 3 people with Parkinson’s disease, and parallel detailed documentation of all changes and decisions. In the first translation stage of the C-FOG two professional translators provided two different preliminary German translations. The original questionnaire was divided into 62 translation units to provide a detailed descriptive analysis of the adaptations made in each step of the translation process. During the review stage, 31 units (50%) of the preliminary translations required adaptation. During the pre-test stage, the participants discussed the German translation of the C-FOG that had been adjudicated in the previous stage. This resulted in the need for further adaptations of 25 translation units (40%), while 37 units (60%) required no additional changes. Following back-translation by a professional translator and feedback from the first author of the original questionnaire, the German version of the C-FOG, the C-FOG-D, was finalized. This study provides a systematically conducted German translation of the Characterizing Freezing of Gait Questionnaire using the TRAPD process to ensure understandability and equivalence to the original questionnaire. A full consensus was reached among the participants involved in the final translation stage. For future validation studies and potential modifications to the questionnaire, it is necessary to include more people with PD experiencing FOG. A larger sample size could offer a more comprehensive perspective on how individuals differ in their perceptions of FOG, and to what extent the language used in the questionnaire effectively captures these experiences.