Stanton, diagnosed with sleep apnea in 2002, said he’d most likely be dead today if he hadn’t received treatment. OSA is a condition in which the body’s airways close while sleeping, typically resulting in “hypoxia” or low blood oxygen levels at night. That leads to interruptions in breathing lasting several seconds at a time, loud snoring, and non-restful sleep. Individuals with OSA are frequently entirely unaware of the condition, with the disorder leading to extreme daytime sleepiness – with sufferer often falling asleep within minutes in a quiet or monotonous environment.

In addition to the substantial risks of impairment or incapacitation as a direct result of the fatigue associated with OSA, left untreated it increases the likelihood of other operationally-relevant medical conditions, including stroke, heart failure, coronary artery disease, and diabetes.

“You don’t know you have it,” Gary Hull, a former trucker and also a member of “Truckers For a Cause,” told FleetOwner. Diagnosed in 2004 with OSA, Hull said the difference for him has been “night and day” in terms of physical well-being.

“I used to only be able to drive two hours before needing to take a break, walk around, get a cup of coffee,” he explained. “OSA is like when you can’t see well; you don’t notice it until you put on glasses and go ‘Wow! Look at what I can see now!’ But if truckers are scared to go the doctor, knowing their livelihood might be taken away if they are diagnosed with OSA, they won’t do it.”

The other problem is that no one really knows how many truck drivers actually suffer from OSA. For example, a study conducted by Alan Pack of the University of Pennsylvania, with funding from the American Trucking Assns. (ATA) and FMCSA, eight years ago estimated that 28% of commercial truck drivers suffer from mild to severe sleep apnea. However, that study was based on a very small sample of drivers – just 406 – raising concern that it might not accurately reflect the true scope of the issue.

As a result, FMCSA is ready to kick off a much broader and longer term study of OSA prevalence among truckers, said Martin Walker, the agency’s research division chief. “Only a handful of studies have been conducted on sleep apnea in the commercial motor vehicle driver arena, and most of the results have been inconclusive,” he said.

Walker pointed to Pack’s research as an example, noting that his driver sample was heavily skewed to short-haul drivers working in crowded urban areas. Furthermore, when Pack compared vehicle crash incidence data between drivers with sleep apnea and those without, there was only a 3% difference in the crash rates. That lead FMCSA to conclude that “no compelling statistical evidence was found to support the hypothesis that sleep apnea increases crash risks among commercial drivers.”

FMCSA’s new research effort – called the Commercial Driver Individual Differences Study (CDIDS) – will consist of medical history data married to information gleaned from a battery of psychological and behavioral measures drawn from 21,000 truck drivers, out of which 3,000 cases and 3,000 controls will be identified, Walker said.

“Our goal is to create a classic controlled study whereby we compared high and low risk drivers to generate ‘odds ratios’ and other statistics quantifying risks associated with various driver factors,” he explained.

A subset of that study will focus on OSA. FMCSA hopes to recruit 1,200 drivers for OSA testing and treatment, then tracking their performance – focusing in particular on long-haul drivers. We hope to kick this study off in October this year,” Walker added.

Until more data surfaces, however, FMCSA is continuing to recommend a “no driving” policy for truckers with sleep apnea. “Drivers with moderate to severe sleep apnea should be medically disqualified,” Dr. Mary Gunnels, the FMCSA’s office of medical programs director, said at the conference.