By Tara Haelle
Drinking and driving don't mix. And driving while being very sleepy can be a big danger too — especially for patients with an untreated sleep disorder.
A recent study found that car accidents and "near misses" were more likely among those with untreated obstructive sleep apnea.
Obstructive sleep apnea is a condition in which a person periodically stops breathing or breathes too shallowly while asleep.
Men in particular were more likely to get into a car accident or have a near miss if they reported feeling very sleepy during the day.
Obstructive sleep apnea is a treatable condition with a device that is usually covered by insurance.
The study, led by Kim L. Ward, BSc, of the Centre for Genetic Origins of Health and Disease at the University of Western Australia, looked at how common car crashes were among individuals with obstructive sleep apnea.
The researchers analyzed questionnaires from 2,673 participants who were suspected of having sleep breathing problems at a hospital-based sleep clinic.
The questions asked about the participants' age, sex, years driving, number of times involved in a motor vehicle crash, number of "near misses" for crashes, sleepiness during the day and amount of caffeine and alcohol they drank.
The participants all underwent a sleep study to determine if they had a sleep disorder and what the severity of it was.
The researchers found that the rate of car crashes among patients with untreated obstructive sleep apnea was about 6 crashes per 100 people per year.
The average crash rate in the general community is 2 crashes per 100 people per year.
The researchers calculated that "very sleepy" men were about 4.7 times more likely to have a "near miss" while driving than men who had normal daytime alertness.
Very sleepy men were also 1.3 times more likely to be involved in a car crash than normal non-sleepy men.
Among women, there did appear to be a slightly higher risk of a car crash among sleepier women, but the data were less clear.
The researchers did not find a pattern among women showing that increasing amounts of sleepiness related to increasing risks of a car crash.
"Untreated obstructive sleep apnea is associated with an increased risk of near misses in men and women and an increased risk of motor vehicle crashes in very sleepy men," the researchers wrote.
They noted that the risk of a near miss or a car crash was highest in patients who were very sleepy during the day, regardless of how severe their sleep apnea was or wasn't.
"This article provides additional information showing the deleterious effects of poor quality or poor quantity sleep," said William Kohler, MD, the medical director of the Florida Sleep Institute in Spring Hill, Florida.
"Anything that can increase daytime sleepiness, whether it be shortened sleep or bad quality sleep – in this case obstructive sleep apnea – would increase the risk for harmful things happening, such as car accidents," he said.
The standard treatment for obstructive sleep apnea is continuous positive airway pressure, or CPAP.
CPAP involves wearing a mask while sleeping. The CPAP machine and mask pump air into the person's air passageways.
CPAP machines require a prescription and can cost anywhere from $150 to over $5,500, though most insurance plans will cover some or all of the expense. CPAP masks range from $30 to $200.
This study was published October 15 in the Journal of Clinical Sleep Medicine.
The research was funded by the Sir Charles Gairdner Hospital Research Foundation, the Hollywood Private Hospital Research Foundation and the ARK from the National Health and Medical Research Council of Australia Enabling Facility.
One author has done sponsored research for RedMed and provided medical advice for Apnex Incorporated. The other authors had no conflicts of interest.