INTRODUCTION: The day-to-day experience of symptoms and functioning are largely understudied in people with Huntington disease (HD). Real-world capture of day-to-day symptoms and functioning could be valuable as future HD outcome measures. Therefore, the purpose of this study was to 1) examine the feasibility of a weeklong intensive study design
and 2) understand the daily variation of symptoms and functioning in individuals with premanifest and manifest HD. METHODS: During this 8-day study, 52 individuals with HD completed real-time symptom reports 3 times each day (chorea, sleep, fatigue, anxiety), wore a wrist-worn device (PRO-Diary sleep and physical activity), and completed daily diaries of symptoms (chorea, sleep, fatigue, anger, depression, anxiety) and functioning (physical activity, speech/swallowing, and social participation) each night. We examined rates of missing data, and multilevel models were used to analyze data. RESULTS: Rates of missing data were 23-52 % for the real-time symptom reports and 19-35 % for the daily diaries. Average PRO-Diary wear compliance was 64 % for manifest and 67 % for pre-manifest HD for sleep, and 71 % for pre-manifest and 78 % for manifest HD for physical activity. Within-subject variability was greater over the week (day-to-day median range 1.9-4.4 SDs) than over the day (within-a-day median range 0-2 SDs). Associations between baseline and real-time reports of the same constructs were generally consistent. CONCLUSIONS: Rates of missing data were consistent with similar study designs in other clinical populations, supporting feasibility. Missingness was highest for the real-time symptom reports. HD participants experienced more day-to-day variation in symptoms and function, with less variability within a day, suggesting that once-daily assessments may suffice.