To look at what role sleep plays in teen car crashes, a team led by Alexandra Martiniuk, an associate professor at the George Institute for Global Health in Sydney, collected data on more than 20,000 drivers aged 17 to 24.
The investigators found that those who said they slept six or fewer hours a night had a 21 percent higher risk of having a car accident than those who got more than six hours of sleep.
Moreover, those who got less sleep on the weekends had a 55 percent increased chance of having a single-car accident, where the car drifts or swerves off the road, they added.
Most accidents (86 percent) happened between 8 p.m. and 6 a.m., the researchers noted.
"Sleeping six hours a night is enough to put young drivers at significant risk of having a car crash. With work, study and social commitments, especially on weekends, it is easy to miss out on the extra hours of sleep we need," Martiniuk said in a statement.
More than 3,000 people die every day in car crashes around the world -- that's more than 1.3 million car-related deaths a year, with between 20 million and 50 million people injured or disabled, the researchers noted.
In the United States alone, it is estimated that 20 percent of all car crashes are the result of drowsy driving, which adds up to 1 million crashes, 50,000 injuries and 8,000 deaths a year, the study found.
For more on teen driving, visit the Children's Hospital of Philadelphia.
SOURCES: Flaura Winston, M.D., PhD, co-scientific director and founder, Center for Injury Research and Prevention, Children's Hospital of Philadelphia; May 20, 2013, JAMA Pediatrics, online
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