Work

P4‐615: Multiple Factor Analysis of Neuropsychological Test Battery Change in the National Alzheimer's Coordinating Center Uniform Data Set

Year: 2019

Type: article

Abstract: At the recommendation of the Neuropsychological Work Group of the NIA Clinical Task Force, the proprietary neuropsychological tests (Form C1) of the National Alzheimer's Coordinating Center (NACC) Uniform Data Set (UDS) were replaced with non-proprietary versions (Form C2). Test equivalents were chosen to model their proprietary counterparts as closely as possible to avoid disruptions to longitudinal data integrity. Correlations between analogous test pairs as measured in a prior Crosswalk Study (CWS) were good (0.68-0.78), but it is unclear whether the paired tests represent the same set of common factors of cognition or if important factors specific to C1 or C2 only exist. We included participants from the NACC UDS and CWS who completed both C1 and C2 neuropsychological batteries within one year with no change in cognitive status (normal cognition, MCI, or dementia). C1 tests include the MMSE, WMS-R Logical Memory (Immediate/Delayed), Digit Span (Forward/Backward), and Boston Naming Test. C2 equivalents include the MoCA, Craft Story 21 Recall (Immediate/Delayed), Number Span (Forward/Backward), and MINT. Tests that were either unchanged from C1 to C2 or did have not a direct counterpart were excluded from the analysis. We performed multiple factor analysis to analyze correlated C1 and C2 data to determine whether the C1 and C2 test batteries are represented by common principal components. Of the 2,363 participants who met inclusion criteria, 1,490 were cognitively normal, 326 had MCI, and 547 had dementia. The first three dimensions explained 72% of the variance of the data, with strong loadings for most test variables on the first dimension. The first two dimensions partially delineated individuals’ cognitive status (Figure 1). Each test pair had very similar loadings on the first two factors (Figure 2). Overall, the C1 and C2 group contributions were almost identical for the first three dimensions (C1: 0.951, 0.268, 0.154; C2: 0.951, 0.256, 0.111).

Source: Alzheimer s & Dementia

DOI: 10.1016/j.jalz.2019.08.163