Drivers with sleep apnea have a five times greater risk of a severe crash when they do not adhere to a mandated treatment program, according to a study co-authored by the Virginia Tech Transportation Institute.

Researchers found that in a group of 1,000 truck drivers working for a year, the drivers with obstructive sleep apnea who refused treatment had 70 preventable serious truck crashes, compared with 14 crashes experienced by an equal-sized group that adhered to treatment or did not have the condition at all.

The study compared more than 1,600 drivers with obstructive sleep apnea with an equal number of drivers who did not have the condition. Drivers with the condition were provided auto-adjusting positive airway pressure treatment and objectively monitored, according to researchers.

"Previous research has shown that obstructive sleep apnea is among the most common causes of excessive drowsiness or fatigue in the daytime, so this new analysis really underscores the risk truck drivers diagnosed with obstructive sleep apnea assume if they choose not to adhere to a treatment program," said Erin Mabry, co-author of the research article and a senior research associate with the Virginia Tech Transportation Institute's Center for Truck and Bus Safety.

The study also found that drivers who did not follow administered treatment were retained at a fleet only one-third as long as drivers who did adhere to treatments. As many as 60% of drivers who chose not to accept mandated treatment quit voluntarily before being discharged.

"These results are important because, currently, drivers who are diagnosed with obstructive sleep apnea at a specific trucking firm with an internal mandated treatment program, and who choose not to accept treatment, can just quit and hire on with a firm that does not have such a program," said Jeff Hickman, one of the study co-authors and a research scientist with the Center for Truck and Bus Safety at the Virginia Tech Transportation Institute. "Given the amount of job turnover in parts of the trucking industry, we can reasonably assume these drivers are going to drive for another firm.”

Data collection and statistical analysis was performed by the Truckers and Turnover Project research team at the University of Minnesota-Morris. The project was funded by Schneider, the University of Minnesota-Morris and the university's Roadway Safety Institute. Treatment was covered without out-of-pocket costs to drivers under Schneider’s employee health insurance.

Virginia Tech researchers collaborated on interpreting the results and writing an article that appeared in the journal Sleep along with representatives from the Harvard Medical School and Precision Pulmonary Diagnostics.