F29 Validation of a novel smartphone-based cogntive assessment tool designed for remote assessment of cognitive functioning in huntington’s disease

Background Cognitive assessment tools developed for use on personal electronic devices can allow convenient collection of large amounts of cognitive data. This methodology is novel in HD and validation must proceed before large scale implementation. Aims We aim to demonstrate discriminant and concurrent validity of our cognitive assessment methodology that involves participants utilising a smartphone app to self-administer cognitive tasks in their home environment. Methods We developed a smartphone app for iOS and Android, which includes informed consent, prompts through study procedures, and two cognitive tasks. We are using the app in a HD study, with currently, n=21; pre-symptomatic=17, symptomatic=4, HD participants, and n=18 control participants, across an eight-day period including self-administration of cognitive tasks (speeded tapping and a visual memory task) on day 1, 4, and 8. ENROLL-HD cognitive data are available for a subset of HD participants (n=11; pre-symptomatic=7, symptomatic=4). Groups were compared on app-based cognitive tasks to assess discriminant validity. For our HD subsample with ENROLL data, app-based and ENROLL cognitive tasks were compared to assess concurrent validity. Results Tapping speed of the HD group was significantly slower than the control group (p=0.013, d=0.83) as was their response time on the visual memory task (p=0.018, d=0.82). Visual memory performance was similar between the two groups. Greater speeded tapping performance and visual memory performance correlated significantly with greater ENROLL HD Symbol Digit Modality Test and verbal fluency performance (Pearson’s r values ranged from.61 – 0.88, p-values from 0.001 to 0.046). Conclusions Current results with a HD sample indicate both promising concurrent and discriminant validity properties of our remote-phone-based cognitive assessment methodology. All participants have completed all tasks, indicating sound usability and acceptability of the app.