The Cognitive-Functional Composite is sensitive to clinical progression in early dementia: longitudinal findings from the Catch-Cog study cohort

Introduction: In an attempt to capture clinically meaningful cognitive decline in early dementia, we developed the Cognitive-Functional Composite (CFC). We investigated the CFC9s sensitivity to decline in comparison to traditional clinical endpoints. Methods: This longitudinal construct validation study included 148 participants with subjective cognitive decline, mild cognitive impairment or mild dementia. The CFC and traditional tests were administered at baseline, 3, 6 and 12 months. Sensitivity to change was investigated using linear mixed models and R2 effect-sizes. Results: CFC scores declined over time (β=-.16,p <.001), with steepest decline observed in mild Alzheimer9s dementia (β=-.25,p <.001). The CFC showed medium-to-large effect-sizes at succeeding follow-up points (R2=.08-.42), exhibiting greater change than the Clinical Dementia Rating scale (R2=.02-.12). Moreover, change on the CFC was significantly associated with informant reports of cognitive decline (β=.38,p<.001). Discussion: By showing sensitivity to decline, the CFC could enhance the monitoring of disease progression in dementia research and clinical practice.