Detection of cognitive impairment using self-rated AD8 and informant-reported AD8

• Published in: Journal of the Formosan Medical Association 2018-01, Vol.117 (1), p.42-47
• Main Authors: Chio, Oi-I, Yip, Ping-Keung, Liu, Yi-Chien, Chen, Li-Hua, Wang, Peng-Chih, Tsai, Tsung-Hsueh, Tang, Sai-Hung
• Format: Article
• Language: English
• Subjects: area under the curve; cognitive disorders; dementia; Internal Medicine; mild cognitive impairment; self-report
• ISSN: 0929-6646; 1876-0821
• DOI: 10.1016/j.jfma.2017.02.015

Abstract Background/Purpose 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. Conclusion Informant-rated AD8 gave more accurate screening results than self-reported AD8 in an out-patient clinic setting.