Health literacy and cognitive performance in older adults

OBJECTIVES: To study the relationship between health literacy and memory and verbal fluency in older adults. DESIGN: Cross-sectional cohort. SETTING: Twenty senior centers and apartment buildings in New York, New York. PARTICIPANTS: Independently living, English- and Spanish-speaking adults aged 60 and older (N=414). MEASUREMENTS: Health literacy was measured using the Short Test of Functional Health Literacy in Adults (S-TOFHLA). The associations between S-TOFHLA scores and immediate and delayed recall (Wechsler Memory Scale II), verbal fluency (Animal Naming), and global cognitive function (Mini-Mental State Examination, MMSE) were modeled using multivariable logistic and linear regression. RESULTS: Health literacy was inadequate in 24.3% of participants. Impairment of immediate recall occurred in 20.4%; delayed recall, 15.0%; verbal fluency, 9.9%; and MMSE, 17.4%. Abnormal cognitive function was strongly associated with inadequate health literacy: immediate recall (adjusted odds ratio (AOR)=3.44, 95% confidence interval (CI)=1.71-6.94, P<.001), delayed recall (AOR=3.48, 95% CI=1.58-7.67, P=.002), and verbal fluency (AOR=3.47, 95% CI=1.44-8.38, P=.006). These associations persisted in subgroups that excluded individuals with normal age-adjusted MMSE scores. CONCLUSION: Memory and verbal fluency are strongly associated with health literacy, independently of education and health status, even in those with subtle cognitive dysfunction. Reducing the cognitive burden of health information might mitigate the detrimental effects of limited health literacy in older adults. Research that examines the effect of materials modified to older adults' cognitive limitations on health literacy and health outcomes is needed.