Validation of the multi-day Boston remote assessment of neurocognitive health (BRANCH) among cognitively impaired & unimpaired older adults.

Abstract

Background: The multi-day Boston Remote Assessment of Neurocognitive Health (BRANCH) is a remote, web-based assessment designed to capture the earliest cognitive changes in the preclinical stage of Alzheimer's disease (AD). It has been validated in unimpaired older adults, but as individuals progress on the AD continuum, assessments need to remain feasible and valid at different clinical stages. The focus of this study was to assess feasibility and validity of multi-day BRANCH in participants with and without cognitive impairment.

Methods: For seven days participants completed the BRANCH paradigm to capture a muti-day learning curve score. Participants also completed the mini-mental-status-exam (MMSE) and the Quick Dementia Rating Scale (QDRS). The primary cohort included 81 older adults: 38 with cognitive impairment (CI) and 43 cognitively-unimpaired (CU). A complementary replication cohort included 16 participants with consensus-defined mild cognitive impairment (MCI) and 47 demographically-matched cognitively unimpaired participants.

Results: Multi-day BRANCH was feasibile with 92 % or participants completing all seven days of testing. More CI than CU reported nervousness and found tasks slightly less enjoyable on Day 1, but ratings increased at a similar rate in both groups. Convergent validity was confirmed by a positive association between BRANCH and total MMSE and QDRS scores. There was a large effect size of group status on BRANCH (CI vs. CU; Cohen's d = 0.83) and per logistic regression, BRANCH significantly predicted group status (β = -1.49, p < 0.001); even more so between MCI and CU in the replication cohort.

Conclusions: Findings suggest that a remotely administered web-based assessment of multi-day learning is feasible and valid in participants with and without cognitive impairment.