Cognitive test norms and comparison to normal cognition and mild cognitive impairment: A population‐based study among community‐dwelling Filipinos

Abstract

AbstractBackgroundClinicians use neuropsychological assessment to screen individuals for cognitive impairment since it more convenient and can detect impaired parts of cognition to provide early treatment. This study is aimed to differentiate the cognitive performance on the Alzheimer’s Disease Assessment Scale – Cognition (ADAS‐Cog) among the older adults with normal cognition and with MCI.MethodThe sample composed of 302 participants aged ≥60 years old who met the score of 25 in the Mini‐mental status examination (MMSE). Psychologists would then administer cognitive measures (ADAS‐Cog, logical memory recognition and delayed recall, verbal fluency on animals and vegetables, digit span forward and backward, digit symbol, and trailmaking A and B) upon meeting. ADAS‐Cog total and subtest scores were compared across the two groups. Receiver operating characteristics (ROC) analysis were performed and, sensitivity and specificity were calculated.ResultMost of the participants are female (81.8%) compared to males (17.9%). 64.2% has normal cognition while 35.8% of them have MCI. The mean age was 69.16 (±5.77) years and mean years of education of 9.11 (±3.57). The MCI group they have a cut‐off ADAS‐Cog score of 13.57(±5.49) (sensitivity= 0.63; specificity= 0.69) while the normal group have a score of 9.96 (±4.79). It also showed significant difference (t=5.971; p≤0.01) among the groups; domains showed a significant relationship i.e.: word list recall, naming, commands, ideational praxis, orientation, word list recognition (p≤0.01) and constructional praxis (p=0.015). Other cognitive measures besides digit symbol (t=1.578; p=0.116) are significant i.e. logical memory recognition and recall, verbal fluency on animals and vegetables, digit span forward and backward, and trailmaking A and B (p≤0.01).ConclusionThe ADAS‐Cog is inapplicable as a screening tool for MCI but specific for MCI diagnosis. There is significant difference found between functional impairment among MCI and normal cognition in the overall and subtests scores.