Adaptive cognitive testing in cerebrovascular disease and vascular dementia.
OBJECTIVE
To examine whether brevity can be combined with precision in measuring global cognitive ability in patients with cerebrovascular disease (CVD) or vascular dementia (VaD). Longer tests (e.g. the CAMCOG) are precise but inefficient, whereas brief tests (e.g. the MMSE) are efficient but imprecise.


METHODS
A simulated computerized adaptive testing (CAT) algorithm using existing CAMCOG data from 284 patients with CVD of whom 55 were diagnosed with VaD. CAT was used to estimate each individual patient's total score on a large precise test (the CAMCOG). CAT repeatedly selected only items of appropriate difficulty, depending on whether the previous item was (in)correctly responded to. CAT estimates were compared with total scores on the whole CAMCOG.


RESULTS
Even though there was an average test reduction of more than 40%, CAT estimates were in very high agreement with the whole test results (intraclass correlation >0.97) and had similar accuracy for the diagnosis of dementia (area under the curve = 0.94).


CONCLUSIONS
CAT combines efficiency with precision in the measurement of global cognitive ability in CVD patients.
Wouters
Hans
H
Department of Clinical Epidemiology, Biostatistics and Bioinformatics, University of Amsterdam, NL-1100 DD Amsterdam, The Netherlands. j.wouters@amc.uva.nl
de Koning
Inge
I
Zwinderman
Aeilko H
AH
van Gool
Willem A
WA
Schmand
Ben
B
Buiter
Maarten
M
Lindeboom
Robert
R
D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002561:Cerebrovascular Disorders / Q000175:diagnosis*; D003072:Cognition Disorders / Q000175:diagnosis*; D015140:Dementia, Vascular / Q000175:diagnosis*; D003936:Diagnosis, Computer-Assisted / Q000592:standards*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000592:standards*; D012372:ROC Curve; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index