Does the Abbreviated Mental Test Accurately Predict Cognitive Impairment in Thai Older Adults? A Retrospective Study.

The Abbreviated Mental Test is a screening tool for cognitive impairment in older adults now used in Thailand's annual national cognitive assessment required for all community-dwelling older adults in Thailand, however its validity has not been established for this purpose. This retrospective study evaluated the results of this abbreviated test as well as the Mini Mental State Examination, in a sample of older adults who participated in the national cognitive assessment in 2018 in Udon Thani Province, Thailand. Of the 174,227 cases, 1518 cases had scores on both tests. The Mini-Mental State Examination is performed on a select group of individuals who scored low on the initial and briefer test. Results indicated that the proportion of cognitive impairment as defined by the Abbreviated Mental Test (87.7%) was five times higher than indicated by the more rigorous Mini-Mental State Examination (16.3%). At the AMT standard cut point of 8 out of a total possible score of 10 for the presence of cognitive impairment, sensitivity was low (12.8%) but specificity was high (90.3%), while the optimal cut-point of 5 on the Receiver Operating Characteristic Curve errs on the side of being highly sensitive but not specific enough to screen for cognitive impairment. Additionally, one item on the AMT was answered incorrectly by 95% of responders. Although brief and easy to administer, the AMT may be a suboptimal choice for screening for cognitive impairment. When administered by volunteer health workers, the AMT may also possess limited reliability and validity. Cognitive screening administered by nurses should be considered to help detect cognitive impairment older adults dwelling in the community.