Evaluation of a Brief Survey Instrument for Assessing Subtle Differences in Cognitive Function Among Older Adults :

Abstract

<p class="first" id="P1">Most measures of cognitive function used in large-scale surveys of older adults have limited ability to detect subtle differences across cognitive domains, and <tt>standard</tt> clinical instruments are impractical to administer in general surveys. The Montreal Cognitive Assessment (MoCA) can address this need, but has limitations in a survey context. Therefore, we developed a survey-adaptation of the MoCA, called the MoCA-SA, and describe its psychometric properties in a large national survey. Using a pretest sample of older adults (n=120), we reduced MoCA administration time by 26%, developed a model to accurately estimate full MoCA scores from the MoCA-SA, and tested the model in an independent clinical sample (n=93). The validated 18-item MoCA-SA was then administered to community-dwelling adults aged 62–91 as part of the National Social life Health and Aging Project (NSHAP) Wave 2 sample (n=3,196). In NSHAP Wave 2, the MoCA-SA had good internal reliability (Cronbach α=0.76). Using item-response models, survey-adapted items captured a broad range of cognitive abilities and functioned similarly across gender, education, and ethnic groups. Results demonstrate that the MoCA-SA can be administered reliably in a survey setting while preserving sensitivity to a broad range of cognitive abilities and similar performance across demographic subgroups. </p>