Predicting conversion from mild cognitive impairment to Alzheimer's disease using neuropsychological tests and multivariate methods.
Behavioral markers measured through neuropsychological testing in mild cognitive impairment (MCI) were analyzed and combined in multivariate ways to predict conversion to Alzheimer's disease (AD) in a longitudinal study of 43 MCI patients. The test measures taken at a baseline evaluation were first reduced to underlying components (principal component analysis, PCA), and then the component scores were used in discriminant analysis to classify MCI individuals as likely to convert or not. When empirically weighted and combined, episodic memory, speeded executive functioning, recognition memory (false and true positives), visuospatial memory processing speed, and visuospatial episodic memory were together strong predictors of conversion to AD. These multivariate combinations of the test measures achieved through the PCA were good, statistically significant predictors of MCI conversion to AD (84% accuracy, 86% sensitivity, and 83% specificity). Importantly, the posterior probabilities of group membership that accompanied the binary prediction for each participant indicated the confidence of the prediction. Most of the participants (81%) were in the highly confident probability bins (.70-1.00), where the obtained prediction accuracy was more than 90%. The strength and reliability of this multivariate prediction method were tested by cross-validation and randomized resampling.
Chapman
Robert M
RM
Brain and Cognitive Sciences and Center for Visual Science, University of Rochester, Rochester, NY 14627–0270, USA. rmc@cvs.rochester.edu
Mapstone
Mark
M
McCrary
John W
JW
Gardner
Margaret N
MN
Porsteinsson
Anton
A
Sandoval
Tiffany C
TC
Guillily
Maria D
MD
Degrush
Elizabeth
E
Reilly
Lindsey A
LA
D000368:Aged; D000544:Alzheimer Disease / Q000523:psychology*; D003072:Cognition Disorders / Q000523:psychology*; D003863:Depression / Q000175:diagnosis / Q000523:psychology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D018450:Disease Progression; D004522:Educational Status; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D015999:Multivariate Analysis; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D025341:Principal Component Analysis; D011379:Prognosis; D011932:Reading; D015203:Reproducibility of Results; D013028:Space Perception / Q000502:physiology; D057190:Stroop Test; D014145:Trail Making Test; D014705:Verbal Behavior; D014936:Word Association Tests