August 18, 2006

Truck drivers who routinely get too little sleep or suffer from sleep apnea show signs of fatigue and impaired performance that can make them a hazard on the road, according to a major new study by researchers at the University of Pennsylvania School of Medicine. The study results are published in the August 15th issue of the American Journal of Respiratory and Critical Care Medicine.

For the study, Penn researchers examined 406 truck drivers and found that those who routinely slept less than 5 hours a night were likely to fare poorly on tests designed to measure sleepiness, attention and reaction time, and steering ability. Drivers with severe sleep apnea also were sleepy and had performance impairment. Nearly 5% of the truckers had severe sleep apnea, and about 13% of the drivers got fewer than 5 hours of sleep a night on a regular basis.

Investigators discovered the following results based on three tests given to measure the daytime sleepiness and performance of the participants:

• Just over 5% of drivers showed impairment on all three performance-related tests.
• Nearly 60% did not fare well by at least one measure.
• About half of the drivers who got less than 5 hours of sleep had two or three impairments. That’s compared to 10% of drivers who got more than 8 hours of sleep regularly.
• Likewise, about 60% of the drivers with severe sleep apnea had two or three impairments.

Penn researchers are now suggesting specific steps for the Federal Motor Carrier Safety Administration to take to improve safety for everyone on our roads:
• Develop strategies to identify impaired drivers through objective testing;
• Implement programs to identify and test drivers with severe sleep apnea and monitor that they stick to their treatment; and
• Introduce programs to assess and promote longer durations of sleep among commercial drivers.