Cognitive Reserve and Cognitive Function in Healthy Older People: A Meta-Analysis

The associations between proxy measures of cognitive reserve (CR) and cognition vary across studies and cognitive domains. This meta-analysis aimed to assess the relationship between CR and cognition in multiple domains (memory, executive function, visuospatial ability, and language). CR was considered in terms of three key proxy measures - educational level, occupational status, and engagement in cognitively-stimulating activities – individually and in combination. One-hundred and thirty-five studies representing 128,328 participants were included. Of these, 109 used a measure of education, 19 used a measure of occupation, 31 used a measure of participation in cognitively-stimulating activities, and six used a combination of these. All three proxy measures had a modest positive association with cognition; occupational status and cognitive activities showed the most variation across cognitive domains. This supports the view that the commonly-used proxy measures of CR share an underlying process but that each additionally provides a unique contribution to CR.