Young children may spend more time watching television than parents estimate if time in front of the tube at preschool is taken into account, researchers said.
And the amount of time kids watch TV at preschool may depend on the type of program the in which child is enrolled.
Preschoolers ages 3 to 5 in childcare programs operated out of someone's home were exposed to significantly more television on an average day than were children in center-based programs -- 2.4 hours versus 0.4 hours, respectively -- according to Dr. Dimitri A. Christakis, and Michelle M. Garrison, of the Center for Child Health, Behavior, and Development in Seattle.
"To our knowledge, these are the first data on daycare television viewing in 20 years, and they suggest that [parental] estimates of preschool-age children's screen time may underestimate actual screen time by more than 100 percent," Christakis and Garrison said in the December issue of Pediatrics.
"Unfortunately, for many children, the potential benefits of preschool may be being displaced by passive TV viewing," Christakis added.
Previous estimates of screen time among preschool-age children were based on parental reports of home viewing, the researchers said. Parental reports put preschoolers' TV time at one to three hours every day.
Estimates of screen time in daycare settings, however, are lacking, they said. So the researchers conducted a telephone survey of childcare programs in Michigan, Washington, Florida, and Massachusetts to assess the frequency and quantity of television viewing among infants, toddlers and preschoolers.
A total of 168 surveys were completed -- 94 from home-based programs and 74 from center-based programs.
The researchers found that preschoolers in childcare programs operated out of someone's home were exposed to six times more television than those in center-based programs.
Toddlers in home-based programs also watched more TV than those in center-based ones: 1.6 hours per day, compared with 0.1 hours.
Among programs that reported using television, toddlers and preschoolers spent an average of 3.4 hours watching TV in home-based programs and 1.2 hours in center-based ones.
Christakis explained why he and his colleagues looked solely at daycare programs that used TV and excluded those that didn't for this particular assessment: "For parents, their child is either at a place that uses [TV] or not. If they are one that uses it, then they would want to know what the average there is."
About 70 percent of home-based program owners reported using television with preschool-aged children, compared with 36 percent of center-based programs.
After controlling for potential confounding factors, center-based programs for preschoolers were found to watch an average of 1.84 fewer hours of television each day compared with home-based programs.
Staff education levels had an impact on TV time. Home-based programs with staffers who had a two- or four-year college degree averaged 1.41 fewer hours of TV per day than home-based programs with staffers who didn't have a degree.
However, there was no impact of staff education on TV use in center-based programs.
"I think most parents expect their child's preschool environment to provide opportunities for cognitive stimulation, social interaction, and physical activity," Christakis said. "Television is a poor substitute for all of those."
The researchers said the study may have been limited by self-reporting and may not be generalized outside of the four states surveyed. Also, they had limited information on the type of content viewed, with no way to assess educational versus entertainment programming.
They concluded that "clinicians must encourage parents to engage their children's caregivers about screen time outside the home as well."