Screen time could be starting in infancy, says NIH study

By Dr. Liji Thomas, MDNov 25 2019

Children nowadays might be risking their developmental health by excessive exposure to screen time. The average time that children stare at the idiot box, or other monitors, including a computer or mobile device, was almost an hour a day at 12 months of age, increasing to over 150 minutes (2.5 hours) by the age of 3 years. Two separate studies published in the journal JAMA Pediatrics show that the children at greatest risk of high screen viewing time are those born to new mothers, or in childcare facilities run from a home.

Available research shows that there is a possibility of impaired childhood development and health with excessive screen time. As a result, the World Health Organization (WHO) has suggested that screen time be restricted during the preschool years, to 1 hour or less per day, and that too, only programs of high quality.

According to the American Academy of Pediatrics guidelines, digital screen time is best avoided before a child is at least 1.5 years of age. The first introduction should be in short segments, between 1.5 and 2 years. After this age, and until the child turns 5 or so, only an hour of screen time should be allowed.

Image Credit: Troyan / Shutterstock

The study

The data for the first study was taken from the Upstate KIDS Study, a database created to follow up children born after their parents were treated for infertility. All the children were born in New York State in the years 2008-2010. After compiling basic demographic data, using birth records and other survey forms, the researchers asked the mothers about the amount of screen time their children had at the age of 1, 1.5, 2, 2.5 and 3 years, and then at 7 and 8 years of age.

The children were divided into 2 groups based on the age-dependent increase in average daily screen time from the age of 1 to 3 years.

In the second study, mothers reported on the screen time for their children, comprising almost 4,000 children altogether. About 1,600 and 2,000 children were aged 2 and 3 years, respectively. The year in which the data was also recorded because digital media have become ubiquitous over just a few years, creating a significant change in the way children have access to these devices.

The findings

The first study

In the first group which made up 73%, the increase was about 51 minutes, on average, with the children finally ending up with 1 hour 47 minutes of screen time a day. Children of more educated parents tended to be in this group. Girls were also a little more likely to be in this group.

In the second group, made up of about 27% of the children, the slope was much steeper, from an initial 37 minutes to about 4 hours a day. Children of first-time mothers were more likely to be in this group.

A percentile chart with respect to screen time shows that children in the highest percentile were twice more likely to be those whose parents had a lower level of education, up to high school graduation or its equivalent. Twins were also more likely to be in this group compared to singletons. In both studies, young children being cared for at home had, unfortunately, a more than twofold risk of high screen watching time, irrespective of the actual caretaker – parent, relative or babysitter. This may be because more screen devices are available at home.

The second study

At the age of 2 years, screen time was likely to be almost three times in excess of the guidelines if the mother watched excessive television or other digital media, and about 70% increased risk with home care. At the age of 3, maternal screen time was the only relevant factor.

However, 80% of 2-year-olds and 95% of 3-year-olds were watching too much television or other similar media. Overall, 87% of children had screen times in excess of the recommended durations - until they turned 7 or 8 years. At this point the total screen watching time dropped to less than 1.5 hours a day, probably because they had joined school by then and did not have as much time for digital media.

Implications

Researcher Edwina Yeung says, “Our results indicate that screen habits begin early. Interventions to reduce screen time could have a better chance of success if introduced early.” Such interventions must consider the screen-watching habits of the rest of the family, as shown by the strong linkage with maternal screen time in one study.

Many decisions will need to be taken jointly within the family, including the how, the where, and the when of such media use, setting up good habits for sleep and physical exercise, and introducing other means of recreation and interactions that maximize interpersonal opportunities.