Screening for cognitive impairment in the elderly: Impact of physical function measures added to cognitive screening instruments

Abstract

This study examines the relationship between cognitive impairment and impaired physical function to determine if the sensitivity and specificity of the Modified Mini-Mental State Examination (3MS) can be improved by the addition of physical function measures. One hundred and sixty-two subjects from the Nova Scotia sample of the Canadian Study of Health and Aging were studied. Subjects were tested using the 3MS and physical function measures prior to undertaking a detailed clinical examination. Receiver Operating Characteristic (ROC) curves were constructed to determine optimal cutpoints for the 3MS and a new 3MS score which included physical function measures. While the 3MS distinguished demented from unimpaired subjects (.9618), it showed less efficiency for classification of unimpaired subjects and subjects who have cognitive impairment without dementia (.7536). the addition of physical function data increased performance of the 3MS in its ability to discriminate unimpaired from demented subjects (.9854), but not significantly. the relationship between cognitive impairment and functional impairment needs clearer definition in cognitively impaired yet non-demented individuals. the addition of widely used function measures is inadequate in improving the parameters of the 3MS as a screening instrument.