Association Between the COVID-19 Pandemic and Early Childhood Development

IMPORTANCE: Although a growing number of studies have reported negative associations of the COVID-19 pandemic with academic performance among school-aged children, less is known about the pandemic’s association with early childhood development. OBJECTIVE: To examine the association between the COVID-19 pandemic and early childhood development. DESIGN, SETTING, AND PARTICIPANTS: In this cohort study conducted in all accredited nursery centers in a Japanese municipality, baseline surveys of children aged 1 and 3 years (1000 and 922, respectively) were conducted between 2017 and 2019, and participants were followed up for 2 years. EXPOSURE: Children’s development was compared at age 3 or 5 years between cohorts that were exposed to the pandemic during the follow-up and a cohort that was not. MAIN OUTCOME AND MEASURE: Children’s developmental age was measured by nursery teachers using the Kinder Infant Development Scale (KIDS). Data were analyzed between December 8, 2022, and May 6, 2023. RESULTS: A total of 447 children (201 girls [45.0%] and 246 boys [55.0%]) aged 1 year at baseline were followed up to age 3 years, and 440 children (200 girls [45.5%] and 240 boys [54.5%]) aged 3 years at baseline were followed up to age 5 years. During the follow-up, the cohorts that were exposed to the pandemic were 4.39 months behind in development at age 5 compared with the cohort that was not (coefficient, −4.39; 95% credible interval, −7.66 to −1.27). Such a negative association was not observed in development at age 3 years (coefficient, 1.32; 95% credible interval, −0.44 to 3.01). Variations in development were greater during the pandemic than before the pandemic regardless of age. Additionally, the quality of care at nursery centers was positively associated with development at age 3 years during the pandemic (coefficient, 2.01; 95% credible interval, 0.58-3.44), while parental depression appeared to amplify the association between the pandemic and delayed development at age 5 (coefficient of interaction, −2.62; 95% credible interval, −4.80 to −0.49; P = .009). CONCLUSIONS AND RELEVANCE: The findings of this study showed an association between exposure to the pandemic and delayed childhood development at age 5 years. Variations in development widened during the pandemic regardless of age. It is important to identify children with developmental delays associated with the pandemic and provide them with support for learning, socialization, physical and mental health, and family support.