Dr. Sanjay Patel, a sleep researcher at Brigham and Women's Hospital and Harvard Medical School in Boston, said sleepiness has played a role in car crashes involving pilots commuting to and from work. Six percent of pilots and 6 percent of train operators said they were involved in a car crash due to sleepiness while commuting, compared to 1 percent of non-transportation workers.
"Driving home from work after a long shift is associated with crashes due to sleepiness," Patel said in a statement. "We should all be concerned that pilots and train operators report car crashes due to sleepiness at a rate that is six times greater than that of other workers."
The study found 18 percent of train operators and 14 percent of truck drivers said they have had a close call on the road due to sleepiness.
The National Sleep Foundation's 2012 Sleep in America poll asked transportation professionals -- including pilots, train operators, truck, bus, taxi and limo drivers -- about their sleep habits and work performance.
About one-fourth of train operators and pilots admit sleepiness affected their job performance at least once a week, compared to 17 percent of non-transportation workers. Roughly 10 percent Americans said they were likely to fall asleep at an inappropriate time and place, such as a meeting or driving, the study said.
Almost one-half of train operators and more than one-third of pilots said their work schedule did not allow adequate time for sleep, Patel said.
The survey of 1,087 U.S. adults age 25 and older -- 795 transportation workers and 292 non-transportation workers -- has a margin of error of 3.5 percentage points.
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