Screen-time does not disrupt children's sleep: Oxford study

Contrary to what most parents might have feared, a new Oxford University study on Tuesday concluded that the time children spend in front of electronic screens has very little effect on their sleep pattern.

In practical terms, while the correlation between screen time - be it televisions, computers or phones - and sleep in children exists, it might be too small to make a significant difference to a child's quantity and quality of sleep, according to the Oxford Internet Institute at the university.

"The findings suggest that the relationship between sleep and screen use in children is extremely modest. Every hour of screen time was related to three to eight fewer minutes of sleep a night," says Professor Andrew Przybylski, author of the study published in the Journal of Pediatrics.

The study was conducted using data from the US 2016 National Survey of Children's Health. Parents from across the country completed self-report surveys on themselves, their children and households.

The study found that when you compare the average nightly sleep of a tech-abstaining teenager (at eight hours, 51 minutes) with a teenager who devotes eight hours a day to screens (at eight hours, 21 minutes), the difference is overall inconsequential. Other known factors, such as early starts to the school day, have a larger effect on childhood sleep.

Przybylski notes, "This suggests we need to look at other variables when it comes to children and their sleep. Focusing on bedtime routines and regular patterns of sleep, such as consistent wake-up times, are much more effective strategies for helping young people sleep than thinking screens themselves play a significant role".

The aim of the study was to provide parents and practitioners with a realistic foundation for looking at screen use versus the impact of other interventions on sleep. While a relationship between screens and sleep is there, we need to look at research from the lens of what is practically significant, the researchers suggest.

When it comes to sleep, there are concerns that children take devices to bed and continue to use them when they should be sleeping. Others have expressed worries about the role the blue light emitted from such devices plays on sleep habits and a related hormone.

"The next step from here is research on the precise mechanisms that link digital screens to sleep. Though technologies and tools relating to so-called 'blue light' have been implicated in sleep problems, it is not clear whether that plays a significant causal role," says Przybylski.

"Screens are here to stay, so transparent, reproducible, and robust research is needed to figure out how tech affects us and how we best intervene to limit its negative effects,' he added.

As the effects of screens are so modest, it is possible that many previous studies with smaller sample sizes could be "false positives" results that support an effect that in reality does not exist.