Sufferers of untreated sleep apnea were 25 times more likely to be involved in a motor vehicle accident than the general population, according to Flinders researcher, Mr Andrew Vakulin.

Mr Vakulin, based at the Adelaide Institute for Sleep Health, Repatriation General Hospital, investigated whether the negative effects of sleep restriction and alcohol on driving ability are more pronounced in untreated obstructive sleep apnea (OSA) patients than in healthy subjects. People with sleep apnea stop breathing for short periods during sleep, which partly awakens them and prevents normal, restful sleep.

The study found that OSA sufferers were more affected by alcohol and sleep restriction than healthy controls. The driving ability of sufferers was shown to be already hampered by OSA and when sleep restriction or alcohol were added, their driving deteriorated more rapidly than healthy people.

“With sleep restriction, steering was the performance indicator most affected. Alcohol also impaired steering deviation but the results were not significantly different from the healthy group,” Mr Vakulin said.

“The OSA group were 25 times more likely to crash than the healthy control group, and were four times more likely to crash under sleep restriction conditions and twice as likely to crash after alcohol when compared to the patients tested under normal sleep conditions,” he said.

“Braking reaction times in the OSA group were slower than healthy controls but there were no condition dependent differences.

“The overall conclusion was that compared with healthy people, those with untreated sleep apnea had worse simulated driving performance. In addition, the negative effects on driving performance of limited sleep and alcohol were greater in people with untreated sleep apnea than in healthy people.”

The findings of 30 month study by Mr Vakulin and his colleagues have just been published in a leading international medical journal, Annals of Internal Medicine.

Mr Vakulin has been recently awarded a scholarship – which commemorates the life and work of leading sleep disorder researcher, the late Dr Helen Bearpark – and will use it assist in travelling to France for about two months to gain new research skills while working in a laboratory in Bordeaux.