Long-term evolution of patient-reported outcome measures in spinocerebellar ataxias

Introduction: To study the long-term evolution of patient-reported outcome measures (PROMs) in the most common spinocerebellar ataxias (SCAs), we analyzed 8 years follow-up data of the EUROSCA Natural History Study, a cohort study of 526 patients with SCA1, SCA2, SCA3 and SCA6. Methods: To assess the functional capacity in daily living, we used the functional assessment (part IV) of the Unified Huntington’s Disease Rating Scale (UHDRS-IV), for health-related quality of life the visual analogue scale of the EuroQol Five Dimensions Questionnaire (EQ-5D VAS), and for depressive symptoms the Patient Health Questionnaire (PHQ-9). Severity of ataxia was assessed using the Scale for the Assessment and Rating of Ataxia (SARA) and neurological symptoms other than ataxia with the Inventory of Non-Ataxia Signs (INAS). Results: UHDRS-IV [SCA1: − 1.35 (0.12); SCA2: − 1.15 (0.11); SCA3: − 1.16 (0.11); SCA6: − 0.99 (0.12)] and EQ-5D [SCA1: − 2.88 (0.72); SCA2: − 1.97 (0.49); SCA3: − 2.06 (0.55); SCA6: − 1.03 (0.57)] decreased linearly, whereas PHQ-9 increased [SCA1: 0.15 (0.04); SCA2: 0.09 (0.03); SCA3: 0.06 (0.04); SCA6: 0.07 (0.04)] during the observational period. Standard response means (SRMs) of UHDRS-IV (0.473–0.707) and EQ-5D VAS (0.053–0.184) were lower than that of SARA (0.404–0.979). In SCA1, higher SARA scores [− 0.0288 (0.01), p = 0.0251], longer repeat expansions [− 0.0622 (0.02), p = 0.0002] and the presence of cognitive impairment at baseline [− 0.5381 (0.25), p = 0.0365] were associated with faster UHDRS-IV decline. In SCA3, higher INAS counts were associated with a faster UHDRS-IV decline [− 0.05 (0.02), p = 0.0212]. In SCA1, PHQ-9 progression was faster in patients with cognitive impairment [0.14 (0.07); p = 0.0396]. Conclusions: In the common SCAs, PROMs give complementary information to the information provided by neurological scales. This underlines the importance of PROMs as additional outcome measures in future interventional trials.SCOPUS: ar.j