Teens sleep time affected by smartphones

For some children, and most adolescents, their smartphone is the center of the universe. I knew this in an abstract way, but I don't think I really appreciated how far it went until I read this article, appearing in JAMA Pediatrics.

Shocking statistic number 1: A recent survey found that around two-thirds of high schoolers sleep next to a phone or tablet, with nearly 43% of them waking at least once per night to respond to messages or texts. I mean, when I was in high school you couldn't wake me for a date with Gates McFadden , but these kids are actively checking their phones at night.

Shocking statistic number 2: 72% of children and 89% of adolescents have a phone or tablet in their bedroom.

Now, we can postulate a lot of bad effects of so much phone exposure. I worry a lot about the social networking dynamics these kids are exposed to, but it's easier to quantify sleep, so we're starting there today.

The JAMA Pediatrics study, out of King's College London, was a meta-analysis of published and unpublished studies evaluating the effect of bedtime smart phone and tablet use on sleep. The researchers combed through more than 450 individual studies, eventually settling on 17 studies of sound enough methodological quality for inclusion. And the results were fairly consistent: Across multiple sleep domains, use of phones and tablets at night are a significant problem.

Studies suggested that about 40% of children will have poor sleep quantity and quality if they use a phone before bed. Compare that to 30% of kids who report poor sleep quality if they don't use a phone. They also found that 13% of kids who use a phone before bed reported excessive daytime sleepiness, compared to just 5% who, you know, just go to sleep.

Caveats abound though. None of these studies were randomized trials – it's possible that kids who use phones at night have other things going on in their lives that contribute to poor sleep quality. Additionally, similar effects were seen among kids who had access to phones at night even if they didn't use them. This calls into question the infamous "blue light" theory – that the blue light emitted by phone screens lowers endogenous melatonin secretion. Rather, perhaps we're simply looking at the effects of increased arousal that a stimulating conversation with a friend or a spirited game of Hearthstone can engender.

But the bottom line is that phones are ubiquitous. What's worse, the social stigma of not having access to a phone is a major concern of teenagers as well. So we should all figure out ways to keep phones out of our kids bedrooms. Or at least we should sleep on it.

ABOUT THE AUTHOR

F. Perry Wilson, MD, MSCE, is an assistant professor of medicine at the Yale School of Medicine. He earned his BA from Harvard University, graduating with honors with a degree in biochemistry. He then attended Columbia College of Physicians and Surgeons in New York City. From there he moved to Philadelphia to complete his internal medicine residency and nephrology fellowship at the Hospital of the University of Pennsylvania. During his post graduate years, he also obtained a Master of Science in Clinical Epidemiology from the University of Pennsylvania. He is an accomplished author of many scientific articles and holds several NIH grants. He is a MedPage Today reviewer, and in addition to his video analyses, he authors a blog, The Methods Man. You can follow @methodsmanmd on Twitter.