Clinical trials in mild to moderate Alzheimer’s Disease (AD) rely on informant reports to characterize study participants’ performance on basic and instrumental activities of daily living. As clinical trials move earlier in the AD continuum, however, these informant-based methods become very problematic. Unlike participants with mild-moderate disease, participants in primary and secondary AD prevention trials are generally healthy, often cognitively normal and largely independent. Thus, these informant-based assessment methods lack sensitivity to the subtle declines in instrumental activities of daily living in this patient population. Also, the inclusion of an informant in study designs is unnecessary, burdensome and may compromise enrollment.
The Virtual Reality Functional Capacity Assessment Tool (VRFCAT) is a direct performance-based assessment of IADL functioning that uses a computer or tablet interface and is appropriate for multiple populations. Unlike informant-based measures, the VRFCAT is completed by the study participant directly; an informant is not required.
In order to evaluate the sensitivity of the VRFCAT to the earliest declines in self-reported cognitive function, our team at VeraSci partnered with academic colleagues to recruit and evaluate 245 healthy young adults (age 20-54) and 308 healthy older adults (age 55-97). Older adults were screened for subjective cognitive decline using the Cognitive Functional Instrument (CFI, also referred to as the ADCS Mail-In Cognitive Function Screening Instrument (MCFSI). The questionnaire was designed to assess recent changes in cognition and functional activities that are commonly affected in the development of MCI. Furthermore, increased CFI scores have been associated with amyloid burden in healthy older adults, suggesting that this self-reported measurement serves as a useful screening instrument for preclinical AD. Of the 308 older adults assessed, 61 met the criteria for Subjective Cognitive Decline based on CFI scores greater than or equal to 4.
Our results demonstrated that the VRFCAT is sensitive to the deficits of in older adults with subjective cognitive decline, as they performed significantly worse than age-matched normative controls on all VRFCAT endpoints. Both groups performed significantly worse than healthy younger adults (age 20-54). Participants with subjective cognitive decline also performed significantly worse than controls on cognition as measured by the Montreal Cognitive Assessment (MoCA) and Brief Assessment of Cognition (BAC) verbal memory. All VRFCAT summary measures had correlations greater than r=0.5 with MoCA performance and assessments of Verbal Memory (p<0.01 for all), suggesting consistency between VRFCAT performance and key cognitive indicators of decline in MCI and AD.
Full results are reported in the current issue of the Journal of Prevention of Alzheimer’s Disease.
A.S. Atkins, A. Khan, D. Ulshen, A. Vaughan, D. Balentin, H. Dickerson, L.E. Liharska, B. Plassman, K. Welsh-Bohmer, R. S.E. Keefe; J Prev Alz Dis 2018;5(4):216-224