The mini mental status exam as a surrogate measure of health literacy.

BACKGROUND

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.

OBJECTIVES

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.

SUBJECTS

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.

MEASURES

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.

KEY RESULTS

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 ≤ 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.

CONCLUSIONS

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.