Drivers with the sleep disorder sleep apnoea are more likely to nod off at the
wheel and fail simulated driving tests than motorists without the condition, new
Scientists from the University Hospital in Leeds, England, conducted two
studies involving sleep apnoea - a pattern of disrupted breathing during sleep -
and driving performance.
In one study, they tested the driving ability of 133 patients with untreated
sleep apnea and 89 people without the condition using a simulated driving test.
As they navigated the roughly 56-mile course, the "drivers" were assessed on
completion, time spent in the middle lane, unprovoked crashes and crashes caused
by veering off the road.
Twice as many people with untreated sleep apnoea (24%) failed the driving
test, compared to 12% of those who didn't have the condition. The researchers
noted many of the sleep apnea patients couldn't complete the test. They also had
more crashes and had difficulty following a clear set of directions given at the
start of the test.
"Driving simulators can be a good way of checking the effects that a
condition like sleep apnoea can have on driving ability," said the study's chief
investigator, Dr Mark Elliott, in a news release from the European Lung
Foundation. "Our research suggests that people with the condition are more
likely to fail the test."
What the study found
In another study, 118 people with untreated sleep apnea completed a survey
about their driving behaviour and also took the simulated driving test. Their
results were compared to those of 69 people who didn't have sleep apnoea.
More than one-third (35%) of those with sleep apnoea admitted to nodding off
while driving. The researchers noted 38% of this group also failed the driving
test. In contrast, only 11% of those without sleep apnoea admitted falling asleep
while driving. And none of the motorists without sleep apnoea failed the driving
Both studies highlight the dangers of untreated sleep apnoea and driving, Dan
Smyth, of Sleep Apnea Europe, said in the news release. "These studies give
weight to the need for provision of sufficient resources for early diagnosis and
treatment of sleep apnoea, where effective treatment ensures a return to
acceptable risk levels for road users."
Interrupted sleep at night leads to daytime fatigue, and sleep apnea has
previously been linked to increased risk for car crashes. People with the
condition are also at greater risk for medical conditions such as high blood
Data and conclusions presented at meetings typically are considered
preliminary until published in a peer-reviewed medical journal.
The US National Heart, Lung, and Blood Institute provides more information on
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