Education, Occupational Environment, and Cognitive Function in Later Life

Objectives
Education is among the most robust predictors of cognitive health outcomes in later life. However, few studies have comprehensively evaluated whether and how much of this effect is explained by occupational exposures. This study aims to determine if and how much pre-retirement occupational exposures (occurring before age 60) mediate the association between education and cognitive function at age 65+.

Methods
We use data drawn from the Health and Retirement Study (HRS) and Occupation Information Network (O*NET) data. Informed by previous research and theory, we conducted Confirmatory Factor Analyses of occupation-level exposure measures using a longitudinal HRS-O*NET linked dataset we created, and we identified two latent factors: occupational hazards and occupational complexity. Among initially employed adults (age 51-60 at baseline), we used Structural Equation Modeling (SEM) to evaluate the association between education and cognitive function at age 65+, and the role of our two occupational factors in mediating this association.

Results
The measurement and structural models both had good model fit (TLI, CFI >= .95, SRMR < .08). We found (a) that education remained a critical predictor of cognitive outcomes in later life even when accounting for occupational exposures, and (b) only hazardous exposures mediated the association between education and cognitive function in later life (a2b2=0.02, p = 0.01), explaining about 17% of the effect of education.

Discussion
These findings suggest interventions designed to decrease exposure to hazardous occupational exposures could reduce some of the cognitive disadvantages in later life associated with lower levels of education.