The Severe Cognitive Impairment Rating Scale--an instrument for the assessment of cognition in moderate to severe dementia patients.
OBJECTIVE
This study aimed to develop a brief, reliable and valid test for cognitive function of severely demented patients.


METHODS
We constructed the Severe Cognitive Impairment Rating Scale, which consisted of 11 items covering memory, language, visuospatial function, frontal function and orientation, and investigated its reliability and validity on 267 subjects [normal: 65, very mild Alzheimer's disease (AD): 42, mild AD: 58, moderate AD: 36, severe AD: 44, profound AD: 22].


RESULTS
The internal consistency obtained by Cronbach's coefficient alpha was 0.93. The interrater reliability and test-retest reliability in the moderately to severely impaired subjects with an MMSE score of <or=14 was 0.99 (p < 0.001) and 0.90 (p < 0.001), respectively. It showed significant correlation with Severe MMSE (r = 0.96, p < 0.01), MMSE (r = 0.86, p < 0.01) and Clinical Dementia Rating (r = -0.83, p < 0.01). It was robust to both the floor effect in the severe/profound stage of AD and the ceiling effect in the mild/moderate stage of AD. Exploratory factor analysis yielded 2 factors (automatic informational processing and controlled informational processing) accounting for 73.5% of the total variance.


CONCLUSIONS
The Severe Cognitive Impairment Rating Scale is a valid and reliable test for evaluating the cognitive function of advanced AD patients.
Choe
J Y
JY
Department of Neuropsychiatry, Seoul National University Bundang Hospital, Gyeonggido, Korea.
Youn
J C
JC
Park
J H
JH
Park
I S
IS
Jeong
J W
JW
Lee
W H
WH
Lee
S B
SB
Park
Y S
YS
Jhoo
J H
JH
Lee
D Y
DY
Kim
K W
KW
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis*; D003072:Cognition Disorders / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests / Q000592:standards* / Q000706:statistics & numerical data; D015588:Observer Variation; D015203:Reproducibility of Results; D012720:Severity of Illness Index