Teenagers’ use of electronic devices before bed and their high screen usage during the day both independently increase the likelihood of sleep deprivation, a study found.
“While the frequency of use differed between the various devices, the relation between different types of electronic devices and sleep remained significant,” Mari Hysing of Uni Research Health in Bergen, Norway, and her associates reported online. “This suggests that the established relationship between TV and sleep found in previous studies can be generalized to newer technology,” they wrote (BMJ Open 2015 Feb. 2 [doi:10.1136/bmjopen-2014-006748]).
The researchers gathered data from 9,846 teens in Hordaland County, Norway, aged 16-19 years, regarding their use of electronic devices during daytime and nighttime and regarding their sleep quantity and quality. They asked about six different device types: personal computer (PC), cellphone, MP3 player, tablet, video game console, and television.
They assessed whether the teens used any of these 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 teens used at least one, and often more than one, electronic device in the hour before bed. More than 80% reported using a PC, more than half reported watching TV, and approximately 90% of girls and 80% of boys had used a cellphone.
Total daily daytime screen use averaged approximately 5.5 hours for girls and more than 6.5 hours for boys.
Teens who used an electronic device in the hour before bed, used screens more than 4 hours total a day, or used any individual electronic device at least 2 hours a day were more likely to have a sleep deficiency of at least 2 hours a day.
Those using a PC 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 PC or cellphone use increased the likelihood of at least 2 hours’ sleep deficit by 53% and 35%, respectively.
Teens were 2.7 times more likely to get less than 5 hours sleep with PC use before bed and 1.85 times more likely with cellphone use before bed. Getting less than 5 hours sleep was 3.6 times more likely with at least 4 hours of total daily screen time.
The research was funded by Uni Research Health and the Norwegian Directorate for Health and Social Affairs. The authors reported no relevant financial disclosures.