Distinct domains of childhood disadvantage and cognitive performance among older Brazilians: Evidence from ELSI-Brazil.

Objective: To investigate the relationship between of distinct domains of childhood disadvantage and cognitive performance among older adults within the context of a middle-income country. Methods: This study used baseline data (2015/2016) from the Brazilian Longitudinal Study of Aging (ELSI), a nationally representative cohort of 9412 adults aged 50 and over. Nine childhood exposure variables were grouped into three domains (family SES, childhood health, and cultural capital), for which scores were created. Survey-weighted Ordinary Least Squares (OLS) regressions estimated the association childhood disadvantage with cognitive performance as measured by immediate memory, late memory and semantic verbal fluency. Mediation analysis assessed whether adulthood socioeconomic status (SES) mediated this relationship of interest. Results: Important disparities in cognitive performance were observed, particularly in terms of age, education, income, occupational status. Before controlling for adulthood SES in the multivariable analysis, all domains of childhood disadvantage were found to be associated with lower cognitive performance across all three measures. After inclusion of adulthood SES variables, the observed associations only remained for semantic verbal fluency. Formal mediation analysis indicated that adulthood SES mediates 47.9% (95% CI: 34.3%-78.6%) of the association between later-life verbal fluency and poor childhood health, and 49.9% (95% CI: 43.6%-57.8%) of the association between later-life verbal fluency and low childhood cultural capital. Conclusions: We found that childhood disadvantage is associated with low performance in memory tests and semantic verbal fluency tests among older Brazilians. Adulthood SES fully mediated the association between all domains of childhood disadvantage and memory performance and only partially mediated its association with verbal fluency. Our findings support policy efforts to enhance early childhood development and improve adulthood SES, and guide additional research to better the mechanisms driving these relationships.