Detection of cognitive impairment using self-rated AD8 and informant-reported AD8.
OBJECTIVE
Screening of dementia can help to initiate proper management of the disorder. The use of the Ascertain Dementia 8-item Questionnaire (AD8) in screening has been promoted in Taiwan recently. The purpose of this study was to compare the psychometric properties and appropriateness of informant-reported and self-rated AD8 in cognitive impairment screening in Taiwan.


METHODS
The AD8 were administered to 153 participants and their informants recruited from two neurology out-patient clinics. The discriminative abilities for early cognitive impairment [Clinical Dementia Rating scale (CDR) 0.5 and 1] of informant-based and self-rating AD8 were determined and compared with their areas under the receiver operating curve. κ coefficients representing the agreement between self-rated and informant-reported AD8 scores were also calculated.


RESULTS
Participants and their informants were aged 76.9 years and 56.0 years on average, respectively. Only informant-reported AD8 was significantly associated with CDR level (Spearman ρ=0.469, p<0.001) and Cognitive Abilities Screening Instrument score (Spearman ρ=-0.458, p<0.001). The item-by-item agreements between self-rated and informant-reported AD8 were poor (κ coefficients: -0.030 to 0.206). The area under the receiver-operator characteristic curve was 0.59 for self-rated AD8 scores, and 0.77 for informant-reported AD8 scores, indicating that the discriminating ability of AD8 scores between CDR 0 and CDR 0.5 or greater is better when reported by informant than when rated by self.


CONCLUSIONS
Informant-rated AD8 gave more accurate screening results than self-reported AD8 in an out-patient clinic setting.
Taiwan Catholic Foundation of Alzheimer's Disease and Related Dementia, Taiwan.
Oi-I
OI
Chio
School of Medicine, Fu Jen Catholic University, Taiwan; Department of Neurology, Cardinal Tien Hospital, Taiwan.
Ping-Keung
PK
Yip
School of Medicine, Fu Jen Catholic University, Taiwan; Department of Neurology, Cardinal Tien Hospital, Taiwan.
Yi-Chien
YC
Liu
Taiwan Catholic Foundation of Alzheimer's Disease and Related Dementia, Taiwan.
Li-Hua
LH
Chen
Department of Clinical Psychology, Fu Jen Catholic University, Taiwan.
Peng-Chih
PC
Wang
Holistic Healthcare Management Consulting Company Limited, Taiwan.
Tsung-Hsueh
TH
Tsai
Taiwan Catholic Foundation of Alzheimer's Disease and Related Dementia, Taiwan. Electronic address: pochaccofans@gmail.com.
Sai-Hung
SH
Tang
D000368:Aged; D000369:Aged, 80 and over; D060825:Cognitive Dysfunction / Q000175:diagnosis*; D003704:Dementia / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009483:Neuropsychological Tests; D011594:Psychometrics; D012372:ROC Curve; D057566:Self Report; D012680:Sensitivity and Specificity; D013624:Taiwan
area under the curve; cognitive disorders; dementia; mild cognitive impairment; self-report