Research: Shift Work Sleep Disorder Increases Risk of Auto Crashes, Escalates Costs

Liz Carey

Itasca, IL ( – New research indicates shiftwork, and the problems it causes with sleep, can increase the risk of automobile crashes.

The research out of the University of Missouri – Columbia’s Department of Civil and Environmental Engineering found that employees who work an extended work shift are 2.3 times more likely to report a crash, and 5.9 times more likely to report a near miss.

Those employees over the age of 24 with shiftwork sleep disorder, where shift workers in non-circadian schedules get inadequate amounts of sleep, are 7.5 times more likely to report a crash or near miss incident. The rate is higher as drivers age, the study found.

“The drowsy-driving crashes are particularly high for shift workers due to disruption of their natural sleep pattern,” the study said. “While driving, lack of sleep results in slower reaction time, poor coordination, and less ability to pay attention. In the age of the digitized world and connected world commerce, the share of shift workers in both blue-collar and white-collar jobs is increasing. Thus, shift work is emerging as a critical factor for traffic and occupational safety.

According to the Bureau of Labors Statistics, in 2019, the most recent data available, more than 5,300 workers died on the job – the largest number since 2007. Of those, 2,122 died in transportation incidents – the largest number since 2011. Of the 888,220 nonfatal injuries and illnesses the Bureau recorded in 2019, more than 49,400 were from transportation incidents.

The study, Sleep disorders and risk of traffic crashes: A naturalistic driving study analysis, looked at nearly 19,000 automobile events in six states to determine if people with three different sleep disorders – sleep apnea, insomnia and shiftwork sleep disorder – were more likely to be involved in an automobile incident.

The study found that drivers with shiftwork sleep disorder were three times more likely to have a crash or near crash. Drivers with shiftwork sleep disorder over the age of 65 were nearly 6 times as likely to have a crash or near crash.

“The analysis showed that drivers with sleep apnea and insomnia were 29 percent and 33 percent more likely, respectively, to be involved in a crash or a near-crash,” the study found. “For drivers with insomnia, factors such as age and sleep quality can elevate the associated crash risk. Decrease in sleep quality increases the likelihood of crash or near crash. The study also found that individuals with a sleep disorder are 29 percent more likely to be inattentive while driving as compared to drivers without a sleep disorder.”

According to the BLS, an estimated 16 percent of American workers work a non-daytime schedule, including 6 percent who worked evenings, 4 percent who worked at night and the rest who worked a rotating shift, a split shift, an irregular schedule or some other schedule.

Researchers said shift workers should consider resting after finishing their shift before driving home, or using non-driving modes of transportation like taxis, ride-sharing companies and public transit.

The Costs

Jenny Burke, senior director of the impairment practice area with the National Safety Council, said sleep disorders contribute to fatigue, which causes nearly 13 percent of all workplace injuries.

“If you’re not doing anything about sleep disorders, it is costing your company money,” she said.

A calculator on the NSC’s web site shows just how much. Factoring in a company’s number of employees, state of residence, number of shifts and main industry, the calculator provides information on how many of a company’s employees likely have a sleep disorder and what it will cost the company each year.

For example, a Kentucky company in the construction industry with 250 employees operating a day, evening and night shift will lose $76,020 in absenteeism, $192,860 in decreased productivity and $137,951 in healthcare costs, according to the calculator. An estimated 31 employees would have sleep apnea and 20 would have insomnia, according to the site.

“Eleven percent of the population suffers from some kind of sleep disorder,” Burke said. “But only 10 percent are addressed.”

Businesses can address the issue by making sure that their health benefits include screening for sleep disorders, she said. Educating employees about the costs fatigue has on the business and on safety is another way to mitigate problems.

The NSC offers a Fatigue tool kit for companies to download to address the issue.

Researchers also suggested the National Transportation Safety Board could establish guidelines for shift workers similar to those established for long haul, commercial drivers, to reduce crashes.

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