Association between early child development trajectories and adult cognitive function in a 50-year longitudinal study in Guatemala

Objectives Few studies have used longitudinal data to study the development of cognition over the life course in low-income and middle-income countries. The objectives of this study were to assess predictors of cognitive development trajectories from 6 months through 7 years, and if these trajectories predicted adult cognitive function in a birth cohort from Guatemala. Design We analysed data from the INCAP Nutrition Supplementation Trial Longitudinal Study in Guatemala. Cognition was assessed at eight different time points between 6 months and 7 years. We derived childhood development trajectories using latent class growth analysis. We assessed predictors of the trajectories using ordinal logistic regression, and associations between childhood trajectories and adult non-verbal intelligence and literacy at age 18-52 years (mean +/- SD =42.7 +/- 6.4 years) using mixed models. Setting The study was conducted in four Guatemalan villages. Participants The study included 927 participants from Guatemala with repeated measurements of cognitive function during the first 7 years of life. Results We identified three trajectories of cognitive development (high: n=214, average: n=583, low: n=130). Participants whose mothers were taller (proportional log odds (PO)=0.03, 95% CI=0.01 to 0.06), had more years of schooling (PO=0.15, 95% CI=0.06 to 0.25), or lived in households with higher socioeconomic scores (PO=0.19, 95% CI=0.09 to 0.29) were more likely to follow higher trajectories. Childhood trajectories predicted adult non-verbal intelligence (high=18.4 +/- 0.3, average=14.6 +/- 0.53, low=11.4 +/- 0.9) and literacy (high=63.8 +/- 2.0, average=48.6 +/- 1.2, low=33.9 +/- 2.6) scores. Conclusions In this sample from Guatemala, cognitive development trajectories from 6 months through 7 years were associated with adult non-verbal intelligence and literacy. These findings provide evidence of tracking of cognition over time in a transitioning low-income setting.