Obese Truck Drivers More Likely to Crash in First Two Years on the Job, Study Says

This story appears in the Nov. 12 print edition of Transport Topics.

Severely obese truck drivers are significantly more likely than their peers to be involved in preventable crashes in their first two years on the job, University of Minnesota  researchers said in a study published this month.

Researchers looked at more than 700 drivers who were hired by truckload carrier Schneider National Inc., Green Bay, Wis., in 2006 and found that drivers with a body mass index of 35 or higher were 54% more likely to get into crashes than the average of all the drivers, according to the study published in the journal Accident Analysis & Prevention.

BMI is a factor of a person’s weight and height, and 35 or higher is categorized as “severely” obese.

“We think it’s a real finding: the severely obese do have a higher risk of accidents that we care about,” Stephen Burks, a University of Minnesota, Morris, professor of economics who led the research, told Transport Topics.

When Burks’ team isolated the most severe crashes, they found that the most obese drivers were still about 50% more likely to be involved in the crashes, Burks said. But the team did not have enough data to make a statistically significant conclusion for the worst crashes, he said.

However, because the data show that minor crashes indicate a risk for more serious ones, Burks said, it is safe to conclude that obese drivers are more at risk of serious crashes.

“About 95% of all accidents are not a great managerial, public-policy concern, except when they tell you about more serious accidents,” he said. The research considered only preventable crashes, Burks said.

He speculated that obstructive sleep apnea is likely to blame for the increased crash risk.

“That’s probably 75% of it,” he said.

Sleep apnea causes sufferers to stop breathing for some periods of time while they sleep, according to the U.S. National Library of Medicine. That decreases the amount of oxygen that goes to the brain, which can cause people to be less alert or attentive and to fall asleep unexpectedly during the day.

Obesity is one of the top risk factors for sleep apnea, Burks said. His team is researching the potential link between sleep apnea and crash risk, but it has not published any findings on that yet.

Recognizing the risks associated with the condition, the Federal Motor Carrier Safety Administration plans to recommend that obese commercial drivers be screened for OSA — and treated if they have it — before being allowed to drive (10-15, p. 5). FMCSA would ask that medical professionals screen all drivers with a BMI of 35 or higher, Elaine Papp, head of the agency’s office of medical programs, said last month.

American Trucking Associations has requested that FMCSA issue a formal regulation concerning sleep apnea instead of the guidance it plans to issue late this year or early in 2013. The regulation process would allow for more formal input than guidance, ATA Chairman Michael Card said. ATA officials were not available to comment on Burks’ research.

For Schneider National, the obesity research reinforced what the carrier had already believed.

“Historically, as many motor carriers focused on driver wellness, it was primarily motivated by the expectation that improved health and wellness would reduce health care costs,” said Don Osterberg, Schneider’s senior vice president of safety. “The part that was always unknown is: Is there any correlation between obesity and crash risk? I think this study validated that, yes indeed, there is.”

Carriers have usually focused on driver health to reduce costs from both health care and missed work days, Osterberg said. But Burks’ research shows that obesity can risk a carrier’s safety and cost the company money from crash involvement.

“As we think about investing in wellness programs, we can now look at it more broadly, not just to reduce health care costs, to reduce injuries, to reduce worker’s comp costs, but also to improve overall fleet safety,” he said.

Schneider National has been proactive in driver health during the past decade and has found that a combination of health screening and face-to-face meetings with health counselors is most effective at fighting obesity, Osterberg said.

The truckload carrier has also tested obese drivers for OSA since 2004 and treated the ones who have the condition, he said. “Today, we have over 2,200 of our drivers who are being treated for that condition,” he said.