Study also finds afternoon teen crash rates were higher than the morning crash rates in two cities
WEDNESDAY, June 9 (HealthDay News) -- Earlier school start times may lead to an increased number of teenage car crashes due to insufficient sleep, as earlier start times likely promote sleep deprivation and daytime sleepiness among teens that can reduce alertness, according to data presented at SLEEP 2010, the annual meeting of the Associated Professional Sleep Societies, held from June 5 to 9 in San Antonio.
Robert D. Vorona, M.D., of Eastern Virginia Medical School in Norfolk, and colleagues evaluated data on the number of drivers ages 16, 17 and 18 years in the city of Virginia Beach and in the adjacent city of Chesapeake for 2008 provided by the Virginia Department of Motor Vehicles.
The researchers found that the number of car crashes in 2008 was higher in Virginia Beach, where high school classes began at 7:20 a.m., compared to Chesapeake, where classes started at 8:40 a.m. (65.4 versus 46.2 automobile crashes for every 1,000 teen drivers). Afternoon teen crash rates were higher than morning crash rates in both cities, with a six-hour analysis demonstrating that the overall afternoon crash rate per 1,000 teen drivers was higher in Virginia Beach compared to Chesapeake (35.2 versus 20.6). In addition, the afternoon crash rate peaked from 2 p.m. to 6 p.m. in Virginia Beach where school ended around 2 p.m., and peaked from 4 p.m. to 5 p.m. in Chesapeake where school ended at about 3:40 p.m.
"We believe that high schools should take a close look at having later start times to align with circadian rhythms in teens and to allow for longer sleep times," Vorona said in a statement.
The study was supported by the Eastern Virginia School of Medicine Division of Sleep Medicine.
Abstract No. 0546