Measurement of functional cognition and complex everyday activities in older adults with mild cognitive impairment and mild dementia: validity of the large Allen's cognitive level screen

OBJECTIVE: To explore the validity of the Large Allen's Cognitive Level Screen-5 (LACLS-5) as a performance-based measure of functional cognition, representing an ability to perform complex everyday activities in older adults with mild cognitive impairment (MCI) and mild dementia living in the community.

METHODS: Using cross-sectional data from the Sydney Memory and Ageing Study, 160 community-dwelling older adults with normal cognition (CN; N = 87), MCI (N = 43), or dementia (N = 30) were studied. Functional cognition (LACLS-5), complex everyday activities (Disability Assessment for Dementia [DAD]), Assessment of Motor and Process Skills [AMPS]), and neuropsychological measures were used.

RESULTS: Participants with dementia performed worse than CN on all clinical measures, and MCI participants were intermediate. Correlational analyses showed that LACLS-5 was most strongly related to AMPS Process scores, DAD instrumental activities of daily living subscale, Mini-Mental State Exam, Block Design, Logical Memory, and Trail Making Test B. Multiple regression analysis indicated that both cognitive (Block Design) and functional measures (AMPS Process score) and sex predicted LACLS-5 performance. Finally, LACLS-5 was able to adequately discriminate between CN and dementia and between MCI and dementia but was unable to reliably distinguish between CN and MCI.

CONCLUSION: Construct validity, including convergent and discriminative validity, was supported. LACLS-5 is a valid performance-based measure for evaluating functional cognition. Discriminativevalidity is acceptable for identifying mild dementia but requires further refinement for detecting MCI.