A commonly cited reason for the infrequent detection of cognitive impairment in the Emergency Department (ED) is the lack of an appropriate screening tool. The Abbreviated Mental Test 4 (AMT4) is a brief instrument recommended for cognitive screening of older adults in the ED. However, its exact utility in the detection of altered mental status in the ED is yet to be fully determined.Methods
The present study evaluated the ability of the AMT4 to identify impaired mental status in the ED, defined as positive scores on either the Confusion Assessment Method-ICU for delirium, the standardized Mini Mental State Examination as a general cognitive screener or the Eight-item Interview to Differentiate Aging and Dementia for dementia.Results
Of 196 adults at least 70 years of age (mean: 78.5±5.9), the AMT4 had a sensitivity of 0.53 (0.42–0.63) and a specificity of 0.96 (0.89–0.99) for impaired mental status in the ED. The AMT4 was positive in almost all patients (92%; 24/26) screening positive for delirium, but less than half (47.8%; 22/46) of those screening positive for probable dementia, and less than a quarter (22.2%; 6/27) of those screening positive for probable cognitive impairment.Conclusion
The present study found that the limited sensitivity of the AMT4 in identifying the majority of cognitively impaired persons restricts its use in isolation as a general cognitive screener in the ED.