Study: Daily Smartphone Associated With Reduced Sleep

It’s well known that using a smartphone in the evening can make going to sleep more difficult, due to the light emitted by the screen.  However, new research indicates that regular smartphone use in general is also associated with less sleep.

Smartphones are increasingly becoming an indispensable part of everyday life.  However, poor sleep is associated with health conditions such as obesity, diabetes and depression.

Researchers at the University of California in San Francisco sought to test the hypothesis that increased screen-time may be associated with poor sleep by analyzing data from 653 adult individuals across the United States participating in the Health eHeart Study. Participants installed a smartphone application which recorded their screen-time, defined as the number of minutes in each hour that the screen was turned on, over a 30-day period. They also recorded their sleeping hours and sleep quality.

The researchers found that each participant totaled an average of 38.4 hours of screen time over this period, with smartphones being activated on average for 3.7 minutes in each hour. Longer average screen time was associated with poor sleep quality and less sleep overall, particularly when smartphones were used near participants’ bedtime.

The authors state that their study is the first to measure smartphone exposure prospectively, but caution that the study also had some important limitations, including the self-selection of study participants and self-reporting of data. While the authors’ findings cannot show causation or exclude the “effect-cause” that poor sleep could lead to more screen time, the association they found could fit with the theory that bedtime smartphone use may negatively impact sleep.

Source: News Release

high-angle shot of a young caucasian man wearing pajamas and colorful striped socks using a smartphone in bed