Impact of Functional Deficits in Instrumental Activities of Daily Living in Mild Cognitive Impairment: A Clinical Algorithm to Predict Progression to Dementia.

BACKGROUND: The utility of functional deficits in patients with mild cognitive impairment is not established.

MATERIALS AND METHODS: In 3886 individuals with mild cognitive impairment evaluated and followed at 34 National Alzheimer Coordinating Center sites, informant-reported Pfeffer Functional Activities Questionnaire (FAQ) items associated with progression to dementia were derived in a training set (n=1943) and tested in the validation set (n=1943).

RESULTS: In the training set, the optimal combination comprised 6 FAQ items (FAQ6): difficulties with finances (2 items), remembering events/appointments, playing games of skill, current events, and travel. In the validation set, hazard ratio for dementia increased from 2.00 for 1 FAQ6 deficit to 5.56 for 6 FAQ6 deficits. In patients 50 to 67 years old with high Mini Mental State Exam scores, dementia risk rose from 12.06% for no FAQ6 deficits to 56.75% for 6 functional deficits. Likelihood of progression to dementia reached 80% to 89% in older age groups with low Mini Mental State Exam and severe FAQ6 deficits.

CONCLUSIONS: Specific functional deficits increased dementia risk and, with age and global cognition, constituted a validated clinical algorithm to estimate dementia risk. Clinicians can use this clinically important algorithm to personalize decision-making about further investigation and identify high-risk patients for early treatment or inclusion in clinical trials.