Children's average daily time spent watching television or using a computer or mobile device increased from 53 minutes at age 12 months to more than 150 minutes at 3 years, according to an analysis by researchers at the National Institutes of Health, the University at Albany and the New York University Langone Medical Centre. By age 8, children were more likely to log the highest amount of screen time if they had been in home-based childcare or were born to first-time mothers.
"Our results indicate that screen habits begin early," said Dr Edwina Yeung, the study's senior author and an investigator in the epidemiology branch of NIH's Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). "This finding suggests that interventions to reduce screen time could have a better chance of success if introduced early."
NICHD researchers and their colleagues analysed data from the Upstate KIDS Study, originally undertaken to follow the development of children conceived after infertility treatments and born in New York State from 2008 to 2010. Mothers of nearly 4,000 children who took part in the study responded to questions on their kids' media habits when they were 12, 18, 24, 30, and 36 months of age. They also responded to similar questions when the children were 7 and 8 years old. The study compiled additional demographic information on the mothers and children from birth records and other surveys.
The American Academy of Paediatrics recommends avoiding digital media exposure for children under 18 months of age, introducing children 18 to 24 months of age to screen media slowly, and limiting screen time to an hour a day for children from 2 to 5 years of age. In the current study, researchers found that 87% of the children had screen time exceeding these recommendations. However, while screen time increased throughout toddlerhood, by age 7 and 8, screen time fell to under 1.5 hours per day. The researchers believe this decrease relates to time consumed by school-related activities.
The study authors classified the children into two groups based on how much their average daily screen time increased from age 1 to age 3. The first group, 73% of the total, had the lowest increase, from an average of nearly 51 minutes a day to nearly an hour and 47 minutes a day. The second group, 27% of the total, had the highest increase, from nearly 37 minutes of screen time a day to about 4 hours a day. Higher levels of parental education were associated with lower odds of inclusion in the second group. In addition, girls were slightly less likely to be in the second group, compared to boys, while children of first-time mothers were more likely to be in the high-increase group.
The researchers also classified the children into percentiles based on their total daily screen time. Children were more likely to be in the 10th, or highest, percentile if their parents had only a high school diploma or equivalent (more than twice as likely) or were children of first-time mothers (almost twice as likely). Similarly, compared to single-born children, twins were more likely to belong to the highest screen time group. Compared to children in centre-based care, children in home-based care, whether provided by a parent, babysitter or relative, were more than twice as likely to have high screen time.
Abstract
Importance: Many children begin interacting with screen media as early as infancy. Although screen time is associated with negative developmental consequences, few longitudinal studies in the United States have examined covariates of screen time among children under 3 years of age.
Objectives: To identify trajectories of screen time among children aged 1 to 3 years, to examine their association with screen use at 8 years of age, and to assess potential determinants of screen time.
Design, Setting, and Participants: This prospective birth cohort study included 3895 children (3083 singletons and 812 unrelated multiples) in New York State who had screen time data available for at least 1 time point from 1 to 3 years of age; 1156 children had data at 8 years. The study spanned September 4, 2007, through June 12, 2014, in the first phase, and August 29, 2014, through November 15, 2019, in the second phase. Data analysis for the present study was conducted from September 28, 2018, to July 15, 2019.
Main Outcomes and Measures: Maternal reports of children’s television, movie, and computer game times were summed for total daily screen time at 12, 18, 24, 30, and 36 months of age. Two screen time trajectories (low and increasing use) were classified by cluster analysis, and logistic regression was used to model risk factors for the increasing trajectory. Children exhibiting the highest 10th percentile of screen use at each point were examined, and linear mixed models were used to identify risk factors of this high exposure category.
Results: Among the 3895 children included in the analysis (2031 boys [52.1%] and 1864 girls [47.9%]), median daily screen time increased from 30 (interquartile range, 0-60) minutes at 12 months of age to 120 (interquartile range, 75-200) minutes at 36 months of age. Of 1045 children with complete data at all 5 time points, 279 (26.7%) had an increasing screen time trajectory. Female child sex (adjusted odds ratio [aOR], 0.90; 95% CI, 0.81-0.99) and graduate school levels of paternal (aOR, 0.73; 95% CI, 0.56-0.95) and maternal (aOR, 0.60; 95% CI, 0.47-0.77) education, compared with having completed college, were associated with lower risk of increasing trajectory. Maternal nulliparity was associated with higher risk of increasing trajectory (aOR, 1.14; 95% CI, 1.00-1.30). Children with an increasing trajectory from 1 to 3 years of age had an additional 22 (95% CI, 11-33) minutes per day of screen time at 8 years of age. Covariates associated with the highest 10th percentile of screen exposure included paterman graduate school education compared with college (aOR, 0.63; 95% CI, 0.39-0.99), maternal graduate school education compared with college (aOR, 0.55; 95% CI, 0.37-0.82), maternal nulliparity (aOR, 1.98; 95% CI, 1.50-2.61), twins compared with singletons (aOR, 1.41; 95% CI, 1.05-1.91), non-Hispanic black compared with non-Hispanic white race/ethnicity (aOR, 4.77; 95% CI, 2.25-10.10), and type of care (home-based care aOR, 2.17 [95% CI, 1.38-3.41]; parental care aOR, 2.11 [95% CI, 1.41-3.15]) compared with center-based care.
Conclusions and Relevance: These findings suggest that a range of parental and child characteristics are associated with screen time. Screen time habits appear to track from as early as infancy, emphasizing the need for earlier interventions.
Authors
Mai-Han Trinh, Rajeshwari Sundaram, Sonia L Robinson, Tzu-Chun Lin, Erin M Bell, Akhgar Ghassabian, Edwina H Yeung
[link url="https://www.nichd.nih.gov/newsroom/news/112519-screen-time"]NIH/Eunice Kennedy Shriver National Institute of Child Health and Human Development[/link]
[link url="https://jamanetwork.com/journals/jamapediatrics/article-abstract/2755656"]JAMA Pediatrics abstract[/link]