Insomnia affects around 23 percent of US workers, and brings a national cost for the sleeping disorder at $63.2 billion, a study showed Wednesday.
On average US workers lose 11.3 days of productivity each year due to insomnia, according to a report from the American Academy of Sleep Medicine, to be released in the September 1 issue of the journal Sleep.
"We were shocked by the enormous impact insomnia has on the average person's life," said study author Ronald Kessler, an psychiatric epidemiologist at Harvard Medical School, noting that the disorder remained an "underappreciated problem."
US workers, he added, are not in fact missing work due to insomnia -- they still go to work, but get less done.
"In an information-based economy, it's difficult to find a condition that has a greater effect on productivity," he said.
The study results were made from a national sampling of 7,428 employees, which was part of the larger American Insomnia Study (AIS) conducted in 2008 and 2009, also led by Kessler.
Estimated prevalence of insomnia from the AIS sample came to 23.2 percent among employees, and was discovered to be significantly lower among workers aged 65 and older -- some 14.3 percent. Insomnia was more prevalent among working women (27.1 percent) than males (19.7 percent), according to the figures.
"Now that we know how much insomnia costs the American workplace, the question for employers is whether the price of intervention is worthwhile," said Kessler.
The average annual cost for insomnia treatment range from about $200 for generic sleeping pills, to upwards of $1,200 for behavioral therapy, noted the study.