Examining the Validity and Utility of Montreal Cognitive Assessment Domain Scores for Early Neurocognitive Disorders.

Objectives: Montreal Cognitive Assessment (MoCA) total scores have been widely used to identify individuals with neurocognitive disorders (NCDs), but the utility of its domain-specific scores have yet to be thoroughly interrogated. This study aimed to validate MoCA's 6 domain-specific scores (ie, Memory, Language, Attention, Executive, Visuospatial, and Orientation) with conventional neuropsychological tests and explore whether MoCA domain scores could discriminate between different etiologies in early NCDs.

Design: Baseline data of a cohort study.

Setting And Participants: Study included 14,571 participants recruited from Alzheimer's Disease Centers across United States, aged ≥50 years, with global Clinical Dementia Rating of ≤1, and mean age of 71.8 ± 8.9 years.

Methods: Participants completed MoCA, conventional neuropsychological tests, and underwent standardized assessments to diagnose various etiologies of NCDs. Partial correlation coefficient was used to examine construct validity between Z scores of neuropsychological tests and MoCA domain scores, whereas multinomial logistic regression examined utility of domain scores to differentiate between etiologies of early NCDs.

Results: MoCA domain scores correlated stronger with equivalent constructs (r = 0.15-0.43, P < .001), and showed divergence from dissimilar constructs on neuropsychological tests. Participants with Alzheimer's disease were associated with greater impairment in Memory, Attention, Visuospatial, and Orientation domains (RRR = 1.13-1.55, P < .001). Participants with Lewy body disease were impaired in Attention and Visuospatial domains (RRR = 1.21-1.47, P < .001); participants with frontotemporal lobar degeneration were impaired in Language, Executive, and Orientation domains (RRR = 1.25-1.75, P < .01); and participants with Vascular disease were impaired in Attention domain (RRR = 1.14, P < .001).

Conclusions And Implications: MoCA domain scores approximate well-established neuropsychological tests and can be valuable in discriminating different etiologies of early NCDs. Although MoCA domain scores may not fully substitute neuropsychological tests, especially in the context of diagnostic uncertainties, they can complement MoCA total scores as part of systematic evaluation of early NCDs and conserve the use of neuropsychological tests to patients who are more likely to require further assessments.