Fleets need to be aware of a potentially fatal sleep disorder that research indicates may be responsible for up to a fifth of all motorway accidents in the UK.

The RAC is making the call for better awareness and has joined forces with the Sleep Apnoea Partnership Group to alert drivers to the issue and the dangers of falling asleep at the wheel.

Obstructive sleep apnoea syndrome (OSAS) is a severe form of sleep apnoea which is characterised by symptoms including excessive daytime sleepiness.

OSAS is a serious condition where the muscles in the throat relax too much during sleep, obstructing the airway, which causes the sufferer to temporarily stop breathing and consequently repeatedly wake up to start breathing again.

The sufferer is usually unaware this is going on and it can occur hundreds of times in a night, leading to daytime sleepiness and other serious health problems.

As a result those drivers who have the condition, but who are not being treated, are at risk to themselves and other road users as they are six times more likely to have an accident than other drivers.

In Britain, 5% of the adult population are thought to have undiagnosed sleep apnoea, of which about a quarter have the more severe form of the condition, OSAS.

While 400,000 people have been diagnosed and are being treated for the condition, it is believed that up to 1.4 million drivers have not been diagnosed and may be at risk of falling asleep at the wheel without knowing why.

And, according to the Sleep Apnoea Partnership Group, in tests of simulated driving, sleep apnoea patients had a driving performance at least as bad as drivers over the alcohol limit.

But while there are serious concerns about the danger this creates on the UK’s road network, effective treatment is available which can address the symptoms very quickly and will enable patients to once again drive safely.

RAC technical director David Bizley said: “This issue should be a real concern for anybody who drives a vehicle, whether it’s a car, a van or a heavy goods vehicle (HGV).

“In fact, an activity such as driving on a motorway can exacerbate the problem as it can be extremely monotonous and hypnotic, particularly if you’re already feeling sleepy.

“There is a real need to raise awareness of this issue, particularly among employers who run fleets of vehicles, whether company cars or delivery vans.

“The consequences of falling asleep at the wheel can be catastrophic, both for the driver themselves and anybody in their vicinity.

“But it’s also important to emphasise there is a solution as very effective treatment is available. If you suspect that you may have the condition, speak to your GP and get it checked out.”

Professor John Stradling, a leading sleep clinician and member of the Partnership Group, said: “There is a real lack of awareness by motorists, and sadly also by doctors, not only of the condition, but also of the availability of highly effective treatment.

“The usual treatment is to use a simple continuous positive airway pressure device while asleep which has a very positive effect on many aspects of people’s lives, in particular, abolishing the sleepiness.

“To date, the Partnership Group has been focused primarily on commercial drivers and we are working with some of the larger employers to encourage their support for drivers, concerned they might have OSAS, being tested and treated if necessary.

“Typically, sufferers are often overweight and that extra weight around the neck puts pressure on the throat. A sedentary kind of lifestyle only makes the condition worse, and people who spend a long time behind the wheel seem to be especially at risk.”

Cases of OSA and OSAS have increased as levels of obesity have risen. Nocturnal symptoms include loud snoring, pauses in breathing, occasional choking sensations and restless sleep.

In the case of OSAS further symptoms are present, most notably daytime sleepiness and reduced ability to concentrate. If this sleepiness is sufficient to impair driving, the sufferer must notify the DVLA and will be advised to stop driving.

However, patients with OSA but without daytime sleepiness sufficient to impair driving do not need to contact DVLA and can continue to drive.

It often takes some time before sufferers become aware they have the condition and seek help, and the RAC estimates that as many as one in 20 drivers on the UK’s roads today may be unaware they may be suffering from OSAS and consequently risking accidents, and potentially their lives, each time they get behind the wheel.

But the good news is that studies have shown, that once sufferers are successfully treated, they are no more likely to have road traffic accidents than anyone else.

Prof Stradling adds: “We fully understand that there is a very reasonable concern among drivers about losing their driving licence, but the treatment available today is very effective and need not necessitate a long period of time off the road.

“We agree with the RAC’s call for both better awareness, and improved diagnostic and treatment facilities for those concerned they might have OSAS.”

The Sleep Apnoea Partnership Group is an organisation that comprises of clinicians, academics, charities and other interested parties with the objective of increasing awareness of the condition.

Following a recent collaboration between the Partnership Group and the DVLA, a document has been developed that provides clear guidance on driving with OSA and OSAS.

The full document can be found by clicking here, and the DVLA’s summary by clicking here.