Application of AD-8 to screen very mild dementia in Taiwan
Ching-Kuan Liu,Mei-Chuan Chou,Chiou-Lian Lai,Yuan-Han Yang*
By 2040, Asia will have the highest prevalence of dementia compared to other area. Physicians hope the demented patients can be diagnosed at their earlier stage in order to have desirable therapeutic outcomes. Therefore, easy-to-administer sensitive clinical tools to screen whether people have very mild dementia are expected. The AD-8 scale was developed with higher sensitivity and specificity from Washington University in St Louis to efficiently capture individuals at their very mild dementia. The AD8 is a brief informant-based measure that reliably differentiates non-demented from demented individuals and is sensitive to the earliest signs of cognitive change as reported by an informant. However, given to the different cultural background, we do not know whether the AD-8 is practicable to screen very mild dementia in Taiwanese. We conduct a study to examine the application of AD-8 to screen very mild dementia in Taiwanese.
Participants were recruited from Alzheimer's disease research center in Kaohsiung Medical University Hospital, a medical center in southern Taiwan. Diagnosis of dementia of Alzheimer's type was made according to DSM-IV criteria and referring to neuropsychological test. The English-version AD-8 questionnaire was translated into Chinese and back translated to English to make sure the translative accuracy. For each participant, the clinical dementia rating (CDR) scale and AD-8 were administrated simultaneously during their each assessment. Receiver operating characteristic (ROC) curve was conduct to determine the cut-off values of Chinese version AD-8 in discriminating non-demented from very mild or mild dementia participants.
Two hundreds and thirty-nine participants, including 114 non-demented (CDR0), 73 very mild dementia (CDR0.5), and 52 mild dementia (CDR1) were recruited. The cut-off value of discriminating non-demented subjects (CDR 0) from very mild dementia (CDR 0.5) or from dementia (CDR0.5 and CDR1) was 2 in both groups. The sensitivity 95.89%, specificity 78.07%, and area under curve (AUC) 0.948 were high in discriminating CDR 0 from CDR 0.5 group. In CDR0 versus CDR0.5 and CDR1 group, the sensitivity and specificity were 97.6% and 78.07%, respectively, and AUC was 0.961. Conclusions: AD-8 is a brief and sensitive instrument that can reliably differentiate non-demented from demented, even in very mild stage, subjects in Taiwanese.