Racial/Ethnic Differences in Trajectories of Cognitive Function in Older Adults.

OBJECTIVE: The objective of this study is to (a) examine racial/ethnic differences in trajectories of cognitive function and (b) evaluate the role of education and health behaviors (physical activity [PA] and smoking) as mediators of racial/ethnic differences in the rate of decline in cognitive function in older adults.

METHOD: Data for this study came from the Health and Retirement Study ( n = 3,424). Hierarchical linear models were used to define the trajectory of cognitive function between 2002 and 2008. Participants were classified based on PA as non-vigorously active, intermittent vigorously active, and consistently vigorously active.

RESULTS: After adding education, the Hispanic's and Black's disparities in cognitive performance were slightly attenuated (Hispanics, β = -1.049, p < .001; Blacks, β = -3.397, p < .001) but were still different from Whites. Smoking was not associated with the cognition intercept or rate of decline.

DISCUSSION: We found education had a partial mediating effect on racial differences in levels of cognition but not on the rate of change over time.