Starting School Day Later Lowers Auto Accidents

Letting teens sleep a little more by starting the school day a bit later may lower their odds for car crash injury or death, a new study finds. The researchers found a 16.5% drop in auto accident rates for teen drivers when high schools moved the start of classes from 7:30 a.m. to 8:30 a.m.

The possible reason? More sleep, more alert driving, the researchers said.

After puberty, adolescents are biologically programmed to stay up about an hour later each night. People blame teenagers' sleep deprivation on computers and staying up late to e-mail friends. Probably true, but there is evidence teens get phase-shifted by at least an hour. So you've got biology pushing you later and then you've got the school systems starting an hour earlier. By the end of the week, [kids] are a wreck and our study shows they might actually be in one."

In the study, researchers surveyed around 10,000 students from grades 6 through 12 on their sleep habits and daytime functioning, including auto mishaps. The surveys were completed twice -- first in 1998, when school started at 7:30 a.m., and then again in 1999, when the start time had been moved to 8:30 a.m.

Besides the 16.5% drop in car crashes, the researchers also found that the number of students who got at least eight hours of sleep per night rose from 35.7% in 1998 to 50% after the later school time came into effect.

Kids need at least eight hours and probably closer to nine hours of sleep, Danner said. And as little as an hour less sleep on school nights can have a cumulative effect. That means that by the end of the week, teens are as impaired as if they had stayed up for 24 hours straight.

Discuss this with your kids and alert them to their need to get plenty of sleep.