The Mini Mental Status Exam as a Surrogate Measure of Health Literacy

Studies have documented strong associations between cognitive function, health literacy skills, and health outcomes, such that outcome performance may be partially explained by cognitive ability. Common cognitive assessments such as the Mini Mental Status Exam (MMSE) therefore may be measuring the same latent construct as existing health literacy tools. We evaluated the potential of the MMSE as a surrogate measure of health literacy by comparing its convergent and predictive validity to the three most commonly used health literacy assessments and education. 827 older adults recruited from an academic general internal medicine ambulatory care clinic or one of five federally qualified health centers in Chicago, IL. Non-English speakers and those with severe cognitive impairment were excluded. Pearson correlations were completed to test the convergent validity of the MMSE with assessments of health literacy and education. Receiver Operating Characteristic (ROC) curves and the d statistic were calculated to determine the optimal cut point on the MMSE for classifying participants with limited health literacy. Multivariate logistic regression models were completed to measure the predictive validity of the new MMSE cut point. The MMSE was found to have moderate to high convergent validity with the existing health literacy measures. The ROC and d statistic analyses suggested an optimal cut point of a parts per thousand currency sign 27 on the MMSE. The new threshold score was found to predict health outcomes at least as well as, or better than, existing health literacy measures or education alone. The MMSE has considerable face validity as a health literacy measure that could be easily administered in the healthcare setting. Further research should aim to validate this cut point and examine the constructs being measured by the MMSE and other literacy assessments.