Truck drivers who ignore an existing obstructive sleep-apnea condition are up to five times more likely to be involved in a preventable crash than those who take steps to address their condition, a new study has found.

The study, detailed by researchers Monday, supports calls for regular sleep apnea screening of commercial truck drivers and a system the ensures the condition is treated in order to continue driving, the researchers said.

“It’s estimated that up to 20 percent of all large truck crashes are due to drowsy or fatigued driving, which would account for almost 9,000 fatalities and up to 220,000 serious injuries,” said Stefanos Kales, associate professor in the Department of Environmental Health at Harvard Chan School and a senior author of the study.

The study comes at a time when the Federal Motor Carrier Safety Administration is taking public comment on the dangers of sleep apnea and the costs of screening, diagnosing and treating transportation workers who suffer from the condition.

It was conducted by researchers from Harvard T.H. Chan School of Public Health, University of Minnesota, Morris, and the Brigham and Women’s Hospital in Boston.

“This is a major public health issue and our findings may be the first in a decade to actually push the federal government to mandate sleep apnea screening for these drivers,” Kales said.

The findings could point to a larger public safety issue. The same issue applies to operators of airplanes, buses, ships, trains, and other modes of public transport,” Kales said.

Researchers analyzed data provided by Schneider Inc., a trucking company that began testing drivers for sleep apnea in 2006.

The study compared a control group of 2,016 drivers unlikely to have the disorder with a group of 1,613 drivers that had sleep apnea.

Of the latter group, 682 fully adhered with requirements to use company-provided pressurized air machines, 571 partially adhered to the treatment, and 360 never adhered. For each group, the researchers also looked at data on serious preventable crashes in which the driver was found at fault.

The researchers found that drivers with sleep apnea who didn’t adhere to treatment had a rate of preventable crashes five-fold greater than that of the control group. They also found that drivers with sleep apnea who kept to the company-mandated treatment had a crash rate no different than that of the control group.

Obstructive sleep apnea is a respiratory condition that disrupts breathing during sleep. Sleep apnea can be treated with a machine that provides pressurized air via mask worn over the nose.

These new findings will create a challenge for the trucking industry.

About one-third of truck drivers have some degree of sleep apnea, making it a central issue in truck driver healthcare, said Darrel Drobnich of the American Sleep Apnea Association.

Most of the trucking industry has resisted addressing sleep apnea because it could affect a large portion of their employees, Drobnich said.

“It’s already hard to recruit drivers,” Drobnich said.

The industry has a shortage of about 48,000 drivers, according to the American Trucking Associations.