Introduction. Autosomal recessive cerebellar ataxias (ARCAs) are inherited neurological disorders that can affect both thecentral and peripheral nervous systems. To assess the effects of interventions according to the perception of people affected, patient-reported outcome measures (PROMs) must be available.Objective. This paper presents the development process of the Person-Reported Ataxia Impact Scale (PRAIS), a new PROM in recessive ataxias, and the documentation of its content validity, interpretability, and construct validity (structural and discriminant).Patients and methods.The development followed the PROMIS framework and the Food and Drug Administration guidelines. A mixed-method study design was used to develop the PROM. A systematic review of the literature, semistructured interviews, and discussion groups was conducted to constitute an item pool. Experts' consultation helped formulate items, and the questionnaire was sent online to be completed by people affected. Statistical analyseswere performed to assess the structural and discriminant validity.Results. A total of 125 people affected by recessive ataxia completed the questionnaire. The factoranalysis con rmed the three components: physical functions and activities, mental functions, and social functions. The statistical analysis showed that it can discriminate between stages of mobility and level of autonomy. It showed very good levels of internal consistency (0.79 to 0.89).Conclusion. The Person-Reported Ataxia Impact Scale (PRAIS) is a 38-item questionnaire that assesses the manifestations and impacts of the disease according to the perception of people affected by recessive ataxia. It can be used in clinical and research settings.

Introduction. Autosomal recessive cerebellar ataxias (ARCAs) are inherited neurological disorders that can affect both thecentral and peripheral nervous systems. To assess the effects of interventions according to the perception of people affected, patient-reported outcome measures (PROMs) must be available. Objective. This paper presents the development process of the Person-Reported Ataxia Impact Scale (PRAIS), a new PROM in recessive ataxias, and the documentation of its content validity, interpretability, and construct validity (structural and discriminant). Patients and methods.The development followed the PROMIS framework and the Food and Drug Administration guidelines. A mixed-method study design was used to develop the PROM. A systematic review of the literature, semistructured interviews, and discussion groups was conducted to constitute an item pool. Experts’ consultation helped formulate items, and the questionnaire was sent online to be completed by people affected. Statistical analyseswere performed to assess the structural and discriminant validity. Results. A total of 125 people affected by recessive ataxia completed the questionnaire. The factoranalysis confirmed the three components: physical functions and activities, mental functions, and social functions. The statistical analysis showed that it can discriminate between stages of mobility and level of autonomy. It showed very good levels of internal consistency (0.79 to 0.89). Conclusion. The Person-Reported Ataxia Impact Scale (PRAIS) is a 38-item questionnaire that assesses the manifestations and impacts of the disease according to the perception of people affected by recessive ataxia. It can be used in clinical and research settings.