Nearly one-third of American adults sleep less than six hours each night, a broad new survey shows.
Among nearly 400,000 respondents to the annual National Health Interview Survey, 32.9 percent reported this short sleep in 2017 — up from 28.6 percent in 2004 when researchers began noticing a slight drop in sleep time. That’s a 15 percent increase representing “more than 9 million people, which is about the population of New York City,” says coauthor Connor Sheehan, a sociologist at Arizona State University in Tempe.
Analysis of the annual survey results — accounting for the U.S. population’s age distribution as well as respondents’ marital status, income, employment and lifestyle — suggests people have been sleeping significantly less from 2013 onward, especially black adults, the researchers report online November 17 in Sleep. In 2017, 40.9 percent of black Americans were likely to report short sleep, as were 30.9 percent of whites and 32.9 percent of Hispanics, the researchers calculate.
Americans were more likely in 2017 to report sleeping less than six hours a night than in 2004, but the trend increased most among black and Hispanic people than among white respondents.
Source: C. Sheehan et al/Sleep 2018
This is the first study showing self-reported sleep declining among minorities over time, says Mercedes Carnethon, an epidemiologist at Northwestern University Feinberg School of Medicine in Chicago who was not involved in the study.
Seven hours or more per night is the recommended sleep time, according to the American Academy of Sleep Medicine and the Sleep Research Society. Not getting enough sleep can increase the risk of accidents or of developing conditions such as obesity and diabetes.
Respondents could be sleeping even less than what they reported, the study authors say, since people tend to overestimate the number of hours they sleep. The study did not attempt to explain why some people were sleeping less now than they were 13 years ago, though the researchers suggest stress could be a factor.
The overuse of certain technology, such as cellphones, could also be playing a role. The number of adults owning a smartphone more than doubled in the last decade. Overuse of these devices with attention-seeking screens has been linked to poor sleep and more stress (SN Online: 1/23/17).
“Staring at a bright smartphone screen and getting anxious news is definitely not going to help you go to bed,” Sheehan says.