Reduced opportunities for interaction with people other than parents during the COVID-19 pandemic results in 4-month delay in development at age 5 — Positive influence on children aged 3 years

A research group led by Assistant Professor Koryu Sato of the Graduate School of Medicine at Kyoto University conducted longitudinal surveys that followed 887 children aged 1 and 3 years attending all accredited nursery centers in an undisclosed municipality in the Tokyo metropolitan area. The surveys revealed that children who were exposed to the COVID-19 pandemic were 4.39 months behind in development at age 5 years compared with those who were not exposed to the pandemic. Among children who were exposed to the pandemic, greater between-child and between-nursery variations at ages 3 and 5 years were also observed. The findings are expected to contribute to providing developmental support for children who are infants or at preschool during the pandemic. The study results were published in the July 10, 2023 edition of JAMA Pediatrics.

The effects of the COVID-19 pandemic on the academic performance of school-aged children have been reported in many studies, all of which suggested a negative influence. However, reports on the influence of the pandemic on the development of infants and preschoolers have been scarce due to difficulties in ensuring representativeness and objectivity.

In this study, the research group conducted longitudinal surveys on child development that followed 887 children in 1-year-old and 3-year-old classes in all accredited nursery centers in a municipality in the Tokyo metropolitan area. The first survey was conducted between 2017 and 2019. Two years after the first survey, when the children were in 3-year-old and 5-year-old classes, the second survey was conducted. Children who experienced the COVID-19 pandemic were compared during the follow-up with those who did not experience it.

Children's development was measured objectively by nursery center teachers using the Kinder Infant Development Scale (KIDS). The KIDS is a scale to measure a child's developmental age based on the child's overall ordinary behaviors. It was standardized using data from approximately 6000 infants and children in 38 prefectures across Japan. Each child's overall developmental age and developmental ages in 8 domains (physical motor, manipulation, receptive language, expressive language, language concepts, social relationships with children, social relationships with adults, and discipline) were estimated on the basis of the number of items receiving 'yes' responses from approximately 130 items (the number of items varied depending on the child's age) in the Scale and by using a conversion table.

The comparison and analyses were statistically adjusted for child's age and sex, the child's development at the first survey, the quality of care at nursery centers, parental mental status, birth weight, family structure, household income, and number of days in the nursery per week.

The results showed that children exposed to the pandemic (exposed group) were on average 4.39 months behind in development at 5 years compared with children unexposed to the pandemic (unexposed group), especially in the social relationships with adults, and discipline domains. By contrast, at age 3 years, physical motor, manipulation, language concepts, social relationships with children, and social relationships with adults were rather more developed in the exposed group, and no delay in development was observed. In addition, greater between-child and between-nursery variations were observed in the exposed group both at age 3 and at age 5, especially in the social relationships with adults domain.

A developmental delay of 4.39 months at age 5 years with moderate statistical significance is considered to be too large to ignore. During this developmental stage, children acquire social skills through interactions with people other than their parents. Therefore, reduced communication opportunities with people other than their parents due to the COVID-19 pandemic may have affected them negatively. The greater development observed among the exposed group at age 3 may be due to the positive influence of increased 1-to-1 interactions with adults, important for a child's development during this developmental stage, as a result of increased teleworking among parents. Greater between-child and between-nursery variations in the exposed group at both ages may be caused by differences in family environment and in the responses of nursery centers.

The survey results also showed that children who attended nursery centers with a higher quality of care were likely to exhibit favorable development at age 3 years during the pandemic. By contrast, children whose parents had poor mental health during the pandemic exhibited a remarkable delay in development at age 5 years.

According to Sato, "We still do not know whether the developmental delay from the pandemic in children at age 5 will persist for a long time, and further follow-up is required. It is important to restore a pre-pandemic childcare environment as soon as possible for children's development, while paying attention to the infection situation."

Journal Information
Publication: JAMA Pediatrics
Title: Association Between the COVID-19 Pandemic and Early Childhood Development
DOI: 10.1001/jamapediatrics.2023.2096