Senior Data analyst The Hospital for Sick Children Toronto, Ontario, Canada
Background: Early childhood growth influences future health, development, and learning. School readiness, encompassing physical, social, behavioral, cognitive, and communication competencies, refers to a child’s ability to meet age-appropriate developmental expectations at school entry. Research has shown that overweight or obesity was negatively associated with children’s school readiness. The association of early growth with school readiness remains unknown. Objective: To determine the association of early child growth rate and patterns with school readiness. Design/Methods: A longitudinal cohort study was conducted in children 0 to 6 years enrolled in TARGet Kids! primary care practice-based research network in Toronto, Canada between 2015 and 2022. Two analytical approaches were used to measure growth using child weight and height data between 0 and 4 years: Age- and sex-standardized body mass index (zBMI) growth rate per year using a piecewise linear model; and distinct zBMI trajectories using latent class mixed models. School readiness was measured at 4 to 6 years using the Early Development Instrument (EDI), a validated teacher-completed instrument that assesses skills and behaviours in five developmental domains in kindergarten and is scored according to established cut-offs (vulnerable: Yes/No) and continuously for each domain. Generalized estimating equations were used to assess associations with overall vulnerability (Yes/No) and the continuous score for each domain adjusting for potential confounders. Results: A total of 1,077 children with 6,415 zBMI measurements were included. Mean child age at EDI completion was 4.8 years. 52.6% were male and 70.3% of participants had mothers of European ethnicity. Mean growth rate of the sample was 0.65 zBMI units per year from 0 to 24 months and -0.11 zBMI units per year from 24 to 48 months. Two distinct zBMI trajectories were identified: the stable trajectory (n = 630) and the catch-up trajectory (n = 446). There was insufficient evidence that zBMI growth rates (OR=1.20, 0.75; 1.93, p=0.45 for 0-24 months; OR=0.56, 0.18; 1.74, p=0.29 for 24-48 months) or trajectories (OR=1.11, 0.80; 1.54, p=0.52, catch-up trajectory compared to stable trajectory) were associated with school readiness.
Conclusion(s): We did not find a significant association between early childhood growth and school readiness. Given the higher income and education of our sample, there are limitations in the generalizability of the results. School readiness may be more impacted by factors directly related to obesity or adiposity at the time of EDI measurement rather than growth rate or patterns. Slide1.jpeg
