More Adults Report Excessive Sleepiness in the U.S. than in Europe

Excessive sleepiness is more common in the U.S. than in Europe, which raises concerns for public health and safety, according to a research abstract that will be presented Tuesday, June 8, 2010, in San Antonio, Texas, at SLEEP 2010, the 24th annual meeting of the Associated Professional Sleep Societies LLC.

Results indicate that 19.5 percent of U.S. adults reported having moderate to excessive sleepiness, which was comparable between men and women. Furthermore, 11 percent of participants reported severe sleepiness, which was more prevalent in women (13 percent) than in men (8.6 percent).

“The prevalence of excessive daytime sleepiness is very high in the American population, much higher than what we observed in the European population,” said principal investigator Dr. Maurice Ohayon, professor of psychiatry at Stanford University and director of the Stanford Sleep Epidemiology Research Center in Palo Alto, Calif. In a study published in the June 2002 issue of the journal Neurology, Ohayon reported that the prevalence of excessive daytime sleepiness in five European countries was 15 percent.

“Insufficient sleep is plaguing the American population and is one of the leading factors for excessive daytime sleepiness,” Ohayon added.

The study also found that nearly 18 percent of participants reported falling asleep or being drowsy in situations that required a high level of concentration, such as during meetings or conversations. In these situations people with obstructive sleep apnea were three times more likely to be sleepy (odds ratio = 3.0), people with an insomnia diagnosis (OR = 2.6) and those who typically sleep for six hours or less (OR = 2.5) were over two times more likely to be drowsy, and people who perform night work (OR = 1.9) and those with a major depressive disorder (OR = 1.9) were nearly two times more likely to report sleepiness.

These results raise public safety concerns, particularly regarding the potential for workplace injuries and drowsy driving accidents related to excessive sleepiness.

“The number of individuals sleepy or drowsy during situations where they should be alert is disturbing,” said Ohayon. “Sleepiness is underestimated in its daily life consequences for the general population, for the shift workers and for the people reducing their amount of sleep for any kind of good reasons. It is always a mistake to curtail your sleep.”

The cross-sectional study involved a representa­tive sample of 8,937 people aged 18 or over living in Texas, New York and California. They represented a total of 62.8 million inhabitants. Participants were interviewed by telephone on sleeping habits, health, sleep problems and mental disorders with Sleep-EVAL, a computer program that uses artificial intelligence to simulate some forms of human reasoning and manage specialized knowledge.

The study was supported by the Arrillaga Foundation, the National Institute of Neurological Disorders and Stroke of the National Institutes of Health, and an educational grant from Cephalon.