The use of electronic devices before bedtime and high screen usage during the day independently increase the likelihood of sleep deprivation among teenagers, according to a study published online ahead of print February 2 in BMJ Open.
“While the frequency of use differed between the various devices, the relation between different types of electronic devices and sleep remained significant,” said Mari Hysing, PsyD, a researcher at Uni Research Health in Bergen, Norway. “This [finding] suggests that the established relationship between TV and sleep found in previous studies can be generalized to newer technology.”
Dr. Hysing and her colleagues gathered data from 9,846 participants between ages 16 and 19 in Hordaland County, Norway. The researchers asked participants about their use of electronic devices (ie, personal computers, cellphones, MP3 players, tablets, video game consoles, and televisions) during daytime and nighttime. They also asked about participants’ sleep quantity and quality.
The investigators assessed whether the teenagers used any electronic devices in their bedrooms during the hour before they went to sleep, how often they used them during the daytime, and for what reasons they used the devices. The sleep data included typical bedtimes, rise times, time in bed, and total sleep on weekends and weekdays.
Nearly all teenagers used at least one, and often more than one, electronic device in the hour before bed. More than 80% reported using a computer, more than half reported watching TV, and approximately 90% of girls and 80% of boys reported using a cellphone.
Total daily daytime screen use averaged approximately 5.5 hours for girls and more than 6.5 hours for boys. Teenagers who used an electronic device in the hour before bed, used screens for more than four hours total per day, or used any electronic device for at least two hours per day were more likely to have a sleep deficiency of at least two hours per day.
Participants using a computer or a cellphone in the hour before bed were 52% and 48% more likely, respectively, to take more than 60 minutes to fall asleep. Before-bed computer or cellphone use increased the likelihood of a sleep deficit of at least two hours by 53% and 35%, respectively.
Teens were 2.7 times more likely to get less than five hours of sleep with computer use before bed and 1.85 times more likely to have this outcome with cellphone use before bed. Getting less than five hours of sleep was 3.6 times more likely with at least four hours of total daily screen time.