Children’s use of smartphones and tablets near bedtime is linked to poor sleep and daytime drowsiness, a new analysis has found.

The report, in JAMA Internal Medicine, pooled data from 20 studies involving 125,198 children ages 6 to 18. Among those who had access to a screen device at bedtime at least three times a week, there was an 88 percent increased risk for not getting enough sleep (defined as at least 10 hours a night for children and nine for adolescents), and a 53 percent increased risk of poor sleep quality.

Even having an unused device in the bedroom increased the risk for sleep problems.

The authors acknowledge the studies had limits. All were observational and depended on self-reports, which can be unreliable. It is also possible that poor sleep habits could themselves lead to increasing use of devices.

Still, the lead author, Ben Carter, a senior lecturer in biostatistics at King’s College London, said all the studies seem to point in the same direction. “The most important point is that we need a communitywide strategy to empower parents so that it becomes an acceptable routine to remove devices prior to bedtime.”