Validity and Reliability of the Korean Version of the AD8 Informant Interview (K-AD8) in Dementia

The Alzheimer disease 8 (AD8) is a brief informant-based measure that distinguishes individuals with very mild dementia and mild cognitive impairment from those with normal cognition. The aim of this study was to establish the validity, reliability, and discriminative properties of the Korean version of the AD8 (K-AD8). Evaluation was made oil 155 patient-informant dyads. The K-AD8 scores with the Clinical Dementia Rating (CDR) and performance on neuropsychologic tests were compared. Internal consistency of the K-AD8 was significant (Cronbach alpha = 0.88). The K-AD8 had strong correlation with CDR (Spear-mail rho = 0.76). Concurrent validity was strong with the K-ADS scores correlating with CDR domains and performance on neuropsychologic tests. The K-AD8 wits found to have excellent test-retest reliability (weighted kappa = 0.81) and good interrater reliability (intraclass correlation coefficient = 0.89). The area under the receiver operator characteristic curve was 0.88, suggesting good discrimination between nondemented individuals and those with cognitive impairment. To distinguish CDR 0.5 from CDR 0, in particular, the K-AD8 (cutoff score of 2) had it sensitivity of 68% and it specificity of 90%. In conclusion, the K-ADS is a sensitive screening tool in detecting very early dementia, indicating that the AD8 could work very well in a variety Of Cultural entities.