Discriminant Validity and Time‐effectiveness of A Stepwise Dementia Case‐finding Approach in an Asian Elderly Community

Abstract

AbstractBackgroundTo investigate the discriminant validity and time‐effectiveness of a stepwise dementia case‐finding approach in a community‐based Singaporean older adult population.MethodParticipants who completed the Progressive Forgetfulness Question (PFQ) and the Abbreviated Mental Test (AMT) were invited to phase II and administered the Mini‐Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and a formal neuropsychological battery. Participants were diagnosed by cognitive performance and DSM‐IV criteria into No Cognitive Impairment (NCI), Cognitive Impairment‐No Dementia (CIND) mild (≤2 cognitive domains impaired), CIND moderate (>2 domains impaired) and dementia. Receiver Operating Characteristic were conducted for different cognitive instruments (AMT, MoCA, MMSE) between PFQ = Yes and PFQ = No groups. All discriminant indices including sensitivity, specificity, positive (PPV), negative predictive values (NPV) and accuracy were calculated. Bayesian correction methods were used to adjust the verification bias. Screening time saving and number of subjects further evaluated was estimated in two scenarios with or without the PFQ.ResultThe PFQ showed an NPV of 94.2% for excluding dementia‐free cases after adjustment. After excluding PFQ = No participants, all cognitive tools achieved optimal NPV (>99%). Furthermore, the number of people requiring further evaluation decreased by 129 (42.7%), 58 (36.5%), 25 (14.3%) subjects, corresponding to 48.2%, 48.2%, and 47.8% of screening time being saved, when the PFQ was conducted prior to the MoCA, MMSE, and AMT, respectively.ConclusionUsing a single‐question assessment as the first step of a case‐finding approach, followed up a cognitive test such as the MoCA, could minimize time and resources for further investigation in the community.