Childhood Linear Growth and Early Morbidity as Predictors of Adolescent Cognitive Ability in Malawi: A Prospective Observational Study

Abstract

<h3>Aim</h3><p>Growth faltering and loss of development potential are common in low- and middle-income countries. We aimed to study whether linear growth before and after 2 years, height-for-age Z-score (HAZ) from 1 month until 13 years and morbidity during the first 3 years predict adolescent cognitive ability.</p><h3>Methods</h3><p>Cognitive assessment was done between 2018 and 2019 using Raven's coloured progressive matrices (<em>N</em> = 997), a measure of inductive reasoning and eye-tracking measures of saccadic speed (<em>N</em> = 760) and saccadic control (<em>N</em> = 618) among children whose mothers originally participated in a randomised clinical trial in rural Malawi. Linear regression was used to predict cognitive ability. The primary model was adjusted for age and sex, and the covariate-adjusted model for other prespecified variables.</p><h3>Results</h3><p>Saccadic control was predicted by a change in HAZ between 2 and 13 years in the adjusted model (coef −0.03, <em>p</em> = 0.04). Raven's score was predicted by change in HAZ between 1 month and 2 years (coef. 0.47, <em>p</em> < 0.05), and HAZ at 2, 5 and 13 years (coefs. 0.27–0.38, <em>p</em> < 0.05). Morbidity did not predict adolescent cognition.</p><h3>Conclusion</h3><p>Linear growth before 2 years of age and single HAZ measurements from 2 years onwards associated with later cognitive ability measured with Raven's test, but not consistently with eye-tracking assessment.</p>