Researchers from Harvard Medical School and Harvard School of Public Health are evaluating a new testing and screening method that may help identify commercial drivers at risk for obstructive sleep apnea (OSA), a sleeping disorder that has been found to cause fatigue and slow reaction times. Lead researcher Stefanos N. Kales says the test, which comes in advance of a federal sleep apnea testing requirement, is “extremely promising as a potential, 10-minute frontline check for sleepiness” that can be administered at federally mandated professional drivers’ licensing exams.
An abstract in the Journal of Occupational and Environmental Medicine, which published the study’s findings, described the new method as a “psychomotor vigilance test” that “rapidly assesses attention, reaction time, and abnormal vigilance” and thus may help identify drivers at high risk for OSA and excessive daytime sleepiness.
The test is administered on portable, handheld computers and takes 10 minutes to complete. The Harvard researchers say the results can be quickly read and interpreted.
“Our goal is to develop objective screening methods beyond obesity for obstructive sleep apnea to be used in occupational health settings,” said Mr. Kales, who serves as division chief and medical director of Employee and Industrial Medicine at Cambridge Health Alliance.
“Subjective reports of excessive daytime sleepiness are notoriously unreliable, especially during fitness-for-work examinations, and obesity in isolation as a screen has generated resistance from many drivers,” Kales said.
Fitness levels and fatigue among commercial drivers are of critical concern to U.S. safety regulators, who are working to develop better ways to drive down the number of crashes caused by commercial drivers who fall asleep behind the wheel or suffer from a medical condition that causes them to lose control of their vehicle. Recent studies have found that driver fatigue is often a direct result of OSA, which is predominantly found in obese drivers.
Because long-distance driving is sedentary by nature, as many as half of all commercial drivers in the U.S. are obese – a rate considerably higher than the general population. Safety regulators are discovering the problem is enormous and potential harm to the general public will likely grow if measures aren’t taken to curb the occurrence of OSA and fatigue in commercial drivers.
Study participants who took the 10-minute test were told to react as quickly as they could to certain computer-based cues. Out of 193 male participants, 8 percent displayed delayed reaction times and were categorized as “microsleepers.” The Harvard researchers found that the not all obese participants suffered from OSA, but all participants with signs of OSA were significantly more obese than other participants.