Differences in potentially modifiable factors, such as education, occupation, and late-life social engagement have been associated with cognitive decline and dementia in late life. Whether there is a collective effect of these variables on cognition–cognitive reserve—is unclear. This talk will break reserve into its individual components and compare the importance of each factor in models of cognitive change.
Data came from 13 004 participants of the Medical Research Council Cognitive Function and Ageing Study who were aged 65 years and over. Cognition was assessed at multiple waves over 16 years using the Mini-Mental State Examination. Cognitive change was assessed using a multi-state model that incorporated deaths, right censoring, state misclassification, and cognitive recovery. Cognition was treated as a discrete variable with three possible states: no impairment, slight impairment, and moderate to severe impairment.
Results suggest independent effects for education, occupation, and social engagement. A higher level of education and a more complex occupation were associated with a decreased risk of cognitive decline to a slightly impaired state but they accelerated the transition to death from a severely impaired cognitive state; increased social engagement protected from transitions to severe impairment.
These findings support the possibility that contributions to cognitive reserve or cognitive lifestyle can be made across the life-course.