Transition from cognitively impaired not demented to Alzheimer's disease: an analysis of changes in functional abilities in a dementia clinic cohort.
BACKGROUND
Patients with cognitive impairment no dementia (CIND) are at an increased risk of progression to Alzheimer's disease (AD). Whether subtle impairments in functional or social abilities at the CIND stage can predict progression to AD is not yet fully determined. We evaluated whether impairments on the Disability Assessment for Dementia (DAD) and Functional Rating Scale (FRS) can predict progression to AD.


METHODS
We examined 70 patients with CIND from the ACCORD cohort having complete DAD and FRS baseline and 2-year follow-up data. MANCOVA adjusted for age, sex, education and baseline MMSE score compared the baseline and 2-year change in DAD and FRS scores in CIND patients who progressed to AD versus non-progressors.


RESULTS
There were no significant differences between CIND progressors and non-progressors in baseline total DAD or FRS scores. FRS domain analysis revealed that greater impairment in social/occupational functioning significantly predicted progression, while there were no predictive DAD domains. In progressors, both DAD and FRS scores significantly declined over time with the largest changes in instrumental activities of daily living (IADL).


CONCLUSIONS
While changes in IADL characterize the progression from CIND to AD, impairment in complex social-cognitive competency significantly predicts risk of progression and may mark early AD.
Hsiung
Ging-Yuek R
GY
Division of Neurology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada.
Alipour
Sina
S
Jacova
Claudia
C
Grand
Jacob
J
Gauthier
Serge
S
Black
Sandra E
SE
Bouchard
Rémi W
RW
Kertesz
Andrew
A
Loy-English
Inge
I
Hogan
David B
DB
Rockwood
Kenneth
K
Feldman
Howard H
HH
D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000453:epidemiology* / Q000503:physiopathology*; D000554:Ambulatory Care Facilities; D003072:Cognition Disorders / Q000453:epidemiology* / Q000503:physiopathology*; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012307:Risk Factors; D012720:Severity of Illness Index; D012919:Social Behavior