How useful is the IQCODE for discriminating between Alzheimer's disease, mild cognitive impairment and subjective memory complaints?
BACKGROUND
Informant questionnaires may be useful in diagnosing early dementia. Conflicting results were found when these questionnaires were used to differentiate patients with mild cognitive impairment (MCI) from healthy elderly subjects. We evaluated the ability of the most commonly used informant questionnaire, the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE), to discriminate between Alzheimer's disease (AD), MCI and subjective memory complaints (SMC).


METHODS
Informants of 180 AD patients, 59 MCI patients and 89 SMC subjects who visited the Alzheimer Center of the VU University Medical Center between 2004 and 2007 completed the short Dutch version of the IQCODE. Logistic regression and receiver operating characteristic curves were used to evaluate the diagnostic ability of the IQCODE.


RESULTS
The IQCODE was able to differentiate AD from MCI and SMC, but was not able to differentiate SMC from MCI.


CONCLUSIONS
The IQCODE may be helpful in diagnosing AD but is of limited use in differentiating MCI from SMC.
Alzheimer Center, VU University Medical Center, Amsterdam, The Netherlands. s.sikkes@vumc.nl
Sietske A M
SA
Sikkes
Mark T
MT
van den Berg
Dirk L
DL
Knol
Elly S M
ES
de Lange-de Klerk
Philip
P
Scheltens
Bernard M J
BM
Uitdehaag
Martin
M
Klein
Yolande A L
YA
Pijnenburg
D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000523:psychology*; D003072:Cognition Disorders / Q000175:diagnosis* / Q000523:psychology*; D015331:Cohort Studies; D003937:Diagnosis, Differential; D004569:Electroencephalography; D005260:Female; D006801:Humans; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis* / Q000523:psychology*; D008875:Middle Aged; D015233:Models, Statistical; D017711:Nonlinear Dynamics; D012372:ROC Curve; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires