1. Sleepiness and Driving
Driving requires many simultaneous skills, mainly eye-hand coordination with accurate speed and direction calculations. This requires full concentration, as evidenced by the higher accident rates in those who use mobile phones while driving.
There is good evidence that sleepiness and fatigue are responsible for about 20% of driving accidents. Many of these sleep-related accidents are due to lifestyle issues, such as driving without adequate sleep, and often happen at times when levels of concentration are naturally low; such as in the afternoon and at night. However some are due to medical conditions.
Such accidents are not only devastating to the victims and their families, but are extremely expensive to society, with fatal accidents costing over £1 million each.
2. Why should obstructive sleep apnoea (OSA) affect driving?
The part played by sleep disorders in traffic accidents, particularly obstructive sleep apnoea, has been recognised for over 20 years, with many studies clearly showing a link, particularly when the OSA is severe. OSA can grossly disturb sleep, sometimes producing sufficient excessive sleepiness to explain the higher traffic accident rates in people with OSA.
However, it is not entirely clear what aspects of sleep disturbance in OSA lead to poorer driving ability; is it just sleepiness and briefly ‘nodding off’ at the wheel, or is there also general impairment of driving skills such as eye-hand coordination (similar to the effects of alcohol), or a mixture of both? It is quite clear that only some people who have OSA are at extra risk of having an accident. Why is this the case?
3. Why do only some people with OSA develop sleepiness sufficient to impair driving ability?
The full answer to this question is not known. In studies that have been done on communities in several countries it is clear that more people have OSA without symptoms, than with symptoms. Their bodies and brains seem not to be affected by the sleep disturbance they are getting. This is perhaps not surprising given that other sleep-disturbing circumstances (such as a crying babies and infants who repeatedly wake) affect people differently too. It is also likely that in some people the actual stopping breathing episodes do not ‘wake the brain’ as much as in others.
4. Does this mean that all people with OSA have to stop driving until treated?
Because not all people with OSA become sufficiently sleepy to impair driving the answer is no — not all people with OSA will have to stop driving. The UK Driver and Vehicle Licensing Agency (DVLA) is more concerned with sleepy people, and when OSA does cause excessive sleepiness or other related symptoms we call this obstructive sleep apnoea syndrome (OSAS) rather than just OSA. Thus the assessment of OSA by a specialist may be very important in trying to make this distinction and offer advice about whether driving should continue or not. If your specialist advises you not to drive, you must not drive until the symptoms that cause this medical judgement are mitigated, in most cases by CPAP therapy.
5. What will happen when I go to the clinic to be assessed for OSA or OSAS?
The diagnosis of OSAS and decisions on management requires the combination of a sleep study and an assessment of how sleepy the patient is; both are needed to be able to advise on driving.
It is necessary for you to follow the advice of your specialist on this matter, as the rule changes have made the assessment much more complex and that requires authoritative medical opinion.
6. What are the actual rules about stopping driving and informing the DVLA?
In English law a person is responsible for their own concentration levels (or vigilance) when driving. Thus falling asleep at the wheel and causing an accident is a criminal offence, potentially leading to a prison sentence if the damage resulting is severe and involves loss of life. This is the case regardless of the cause of the sleepiness, be it due to repeated sleep deprivation from normal causes (such as a new baby), or due to a medical condition such as obstructive sleep apnoea syndrome (OSAS). It is assumed that sleepy people know they are sleepy, and therefore know not to drive when they are feeling sleepy. Because of the increased accident rate in patients with OSAS, the DVLA is rightly concerned to prevent unnecessary accidents and want to know about anyone with OSAS, where the symptoms affect the patient’s ability to drive safely.
It is the clinician’s responsibility to advise the patient appropriately as to whether they should inform the DVLA.
It is the responsibility of the person with a medical condition causing impaired ability to drive safely to tell the DVLA, not the clinic or doctor. However, only do this with advice from the Sleep Clinic and only do this by post.
DO NOT PHONE THE DVLA AS THE RESULT CAN VARY CONSIDERABLY DEPENDING UPON WHO YOU SPEAK TO!!
7. What happens when a patient informs the DVLA that they have OSAS?
Fill in the Form SL1 if you drive a car or ride a motorcycle or Form SL1V if you are a lorry, bus or coach driver, but we recommend you do this with the assistance of your Sleep Clinic to make sure that it is entirely accurate medically, as a mistake here could lead to the loss of your driving licence. This is especially important concerning the “Declaration” section, which is quite complicated. We hope that once our discussions with the DVLA have taken place, we will be in a position to explain matters in a simple and clear manner—this is not possible at present, hence this advice.
8. So what should I do and when?
A) No one should drive if they are feeling sleepy, whatever the cause. They should have a sleep or nap until feeling sufficiently refreshed to be safe again.
B) Seek medical attention if this sleepiness is not explicable by life style issues.
C) If you are awaiting assessment for possible OSA with sleepiness or related symptoms sufficient to impair driving, then you need to stop driving (common sense). If the symptoms are not sufficient to impair driving, then you should discuss this with your Sleep Clinic and you may be able to continue driving.
D) Once the diagnosis of OSAS has been made, the specialist will advise you on how to tell the DVLA, when to do this and whether driving can continue at all until after treatment. This is covered in section 4 above.
E) Once successful treatment has begun, then there is no reason for the DVLA to remove or withhold a driving licence. In the case of lorry, bus and coach licences an annual review may be required to ensure treatment remains successful.
9. If your licence is revoked in spite of your Sleep Clinic stating that you are safe to drive, then please contact us and we can provide advice as to the best way to proceed.
The information is given for general information purposes only. It is in no way intended to replace the professional medical care, advice, diagnosis, or treatment of a doctor. If you are worried about any aspect of your health, you should consult a doctor in person.
©SATA update Dec 2016