Digital Cognitive Assessment Leveraging the Boston Process Approach Can Flag Emergent Cognitive Decline in Individuals with Subtle and Mild Functional Disability

Abstract

AbstractBackgroundEarly detection of Mild Cognitive Impairment (MCI) and Alzheimer’s Disease and Related Dementias (ADRD) is key to optimal management. Digital tests allow for the reliable capture of meaningful, process‐based neuropsychological test parameters that traditional paper/pencil measures fail to detect, thus enabling earlier detection. We assessed how subtle functional decline relates to process features extracted from the digital Clock Drawing Test (dCDT) and the digital Trail Making Test‐Part B (dTrB).Methods629 community dwelling participants (58.5% female) were assessed with the Functional Assessment Questionnaire (FAQ), the MMSE, the digital clock drawing test (dCDT) and the digital Trail Making Test‐Part B (dTrB). Three FAQ groups were constructed: FAQ = 0‐2 (minimal functional disability, n = 490); FAQ = 3‐5 (subtle functional disability, n = 90); FAQ = 6‐8 (mild functional disability, n = 49).ResultsParticipants with minimal functional disability were younger (p = 0.027) and scored better on the MMSE (p = 0.001) than other groups. Groups were equated for education. dCDT command/copy component placement was more accurate among participants with minimal functional disability compared to other groups (command dCDT p = 0.001 versus mild functional disability; copy dCDT p = 0.006 versus both subtle and mild functional disability). On the dTrB, participants with minimal disability drew faster than those with subtle or mild disability (mean stroke velocity, p = 0.001). Analyses for percent pen lift time found no difference between participants with minimal versus subtle disability; however, both groups differed from participants with mild disability (p = 0.001). Optimal group classification using stepwise nominal regression with the minimal functional disability group as the reference was achieved using dCDT copy component placement and dTrB mean stroke velocity (X 2 = 28.37, p = 0.001), where dTrB mean velocity entered first (X 2 = 17.73, p = 0.001) followed by dCDT copy component placement (X 2 = 11.19, p = 0.004). Both variables contributed comparably to group classification (Wald statistic range 5.82‐8.88, p = 0.012, respectively).ConclusionsThe digital assessment described above, targeting executive, scanning, visuoconstructional and motor domains, captures highly nuanced, discrete behaviors with precision/ operationalism heretofore unattainable. Consequently, it is reasonable to posit that digital cognitive assessments leveraging the Boston Process Approach can both objectively detect emergent cognitive impairment and infer its likely impact on functional activities, critical for practical assessment in clinical care.