New research finds more Americans have trouble falling asleep and staying asleep. The changes were independent of sleep duration, and difficulties were most prevalent in people with healthy sleep length, the findings show.
Zlatan Krizan, professor of psychology at Iowa State University, and his research team analyzed data collected from nearly 165,000 individuals from 2013 to 2017, as part of the National Health Interview Survey.
Over the course of five years, adults who reported at least one day a week with difficulty falling asleep increased by 1.43 percent and those reporting at least one day with trouble staying asleep increased by 2.7 percent. While the percentages may seem small, Krizan says based on 2018 population estimates this means as many as 5 million more Americans are experiencing some sleep difficulties.
“Indeed, how long we sleep is important, but how well we sleep and how we feel about our sleep is important in its own right,” Krizan says. “Sleep health is a multidimensional phenomenon, so examining all the aspects of sleep is crucial for future research.”
Is It Our Phones?
Based on the National Health Interview Survey data, the researchers cannot say what is contributing to the worsening of sleep quality. However, technology is likely a factor, according to lead author Garrett Hisler, a former Iowa State graduate student and current postdoctoral researcher at the University of Pittsburgh.
“We know from our previous research there is a correlation between smartphone use and insufficient sleep among teens,” Hisler says. “If we’re on our phone before bed or we’re receiving alerts in the middle of the night that can make it harder to fall asleep and stay asleep throughout the night.”
Why Does a Sleep Trend Matter?
Consistent with other studies, the researchers found the average time spent sleeping decreased. Although the number of people who reported waking up and feeling rested also increased, Krizan says this spike was only observed for one year and is less representative of a trend.
By taking a broader look at sleep quality, researchers aim to better understand the link between sleep and health outcomes. In the paper, they explain that sleep duration combined with poor sleep quality can increase the risk for cardiovascular disease, and sleep quality can affect our overall wellbeing.
“We know that how well people sleep is generally very reflective of people’s health and may be an indicator of other conditions,” Krizan says. “If we want a full picture of the population’s health, it’s important to measure and track these changes in sleep trends over time.”
Krizan says the findings suggest that intervention efforts might be more effective by targeting factors that influence the initiation and maintenance of sleep as well as the length of sleep. More research is needed to identify how changes in sleep duration and other sleep characteristics are related.