Don’t sleep on it!

Excessive sleepiness (ES) is the main focus of DVLA concern with people diagnosed with Obstructive Sleep Apnoea (OSA), a condition in which sufferers experience significant periods of not breathing while they are asleep due to airway obstruction (this is to be distinguished from Central Sleep Apnoea which is due to neurological causes).

The consequences of both sorts include inadequate oxygenation of the body, which is bad for general health, and also, because normal deep sleep is interrupted, many of those affected have a tendency to fatigue and fall asleep easily during waking hours, although sufferers may not be aware of this. Those drivers who suffer from and are diagnosed with moderate or severe OSA with the symptom of ES must notify the DVLA, which will investigate to ensure the condition is reviewed and controlled if they wish to continue driving.  swerve

Some reports suggest that about 20 per cent of adults suffer a significant degree of ES, although OSA is only one cause. A far bigger cause is disturbed sleep due to things like shift work and caring duties for infants and sick dependants involving waking nights. Other causes can include use of certain prescription and non-prescription drugs and certain medical conditions. The effects of OSA on sleepiness can be compounded by sleep disruption due to other causes and together, both can combine to increase levels of ES.

ESS (Epworth Sleepiness Scale) and AHI (Apnoea Hypopnoea Index) scores are used by medical practitioners to assess tendency to ES and the severity of OSA, although various research results seem to suggest that ESS results can be quite subjective and sleep specialists warn that they should not be regarded as a wholly reliable assessment of ES. Further research reports have found a weak correlation between AHI and ESS scores. Some people with low AHI scores experience significant EDS while the opposite is also true.

In assessing the risk of sleepiness while driving however, AHI seems to be afforded false significance (due perhaps to the so called ‘McNamara effect’: “We tend afford false significance to the things we can measure because those things that are really significant tend to defy meaningful measurement”). So AHI here serves as a very unreliable proxy measure for tendency to ES. The difficulty is in finding a much more reliable and meaningful means of diagnosing and measuring this problem. At present and for the foreseeable future, the main judgement is made by suitably qualified doctors, who are best at judging a patient’s level of excessive sleepiness, as it is a very transient and subjective state for which there are few reliable markers.

SeatbeltAt present the duty to inform the DVLA about OSA with ES is triggered by medical diagnosis. If you have OSA with ES, you must not drive until the sleepiness is controlled. This applies to all OSA conditions, including those that are suspected. If you are diagnosed with mild, moderate or severe OSA with ES, then driving can only resume with satisfactory symptom control. Moderate and severe sufferers must also advise the DVLA and be subject to regular reviews.

UK law states that that the primary duty not to drive while unfit from any cause rests with the driver. More publicity about sleep and driving may cause some drivers not to go to their doctors for fear of being suspended from driving while awaiting treatment – but in practice this fear is unfounded. Treatment, such as using CPAP (continuous positive airway pressure) equipment during sleep is available via NHS sleep clinics and with a bit of practise, is quite easy to use. It can quickly help the OSA sufferer to feel a whole lot better and have a lot more energy. And there are other, as yet not fully established, benefits such as relief from migraine, normalisation of blood pressure, etc. More guidance about the whole subject is still needed however, for both employers and potential sufferers, to encourage responsible drivers to pay more attention to what is called ‘sleep hygiene’ and find ways of remaining alert when at the wheel.

Drivers need to be cautioned against being too wary of discussing sleepiness issues with their doctors because of fear of being told to stop driving..

The whole subject of sleepiness and road safety has been a big part of RoSPA’s policy and campaigning work on Managing Occupational Road Risk, where we have been campaigning for nearly 20 years (see our advice to employers at The key message we want to get across is that employers must not cause their drivers to drive tired. It needs an intelligent approach. And anyone who feels sleepy at the wheel, regardless of the cause, knows they are becoming impaired and must stop and recover until they are safe to proceed. The most effective ways to counter sleepiness are to drink, for example, two cups of caffeinated coffee and to take a short nap (up to 15 minutes).Brakes2

RoSPA’s National Occupational Health and Safety Committee (which brings together the main institutional stakeholders in this area) has begun a stream of work on tackling fatigue in the workplace. This is not only highly topical because of its links to mental health and ‘wellness’ (now very much higher on everyone’s agenda – and not before time!) but because of its relationship with safety and accidents in the workplace, something that has been very much underplayed up to now in guidance about human factors and safety. New guidance however is now available in the form of the HSE fatigue risk index (see

We are thinking about the idea of producing some guidance on OSA and Employment (‘OSA and your job’ perhaps?), helping both sufferers and their managers to better understand the issues involved and to avoid over-the-top, excessively risk averse responses that might lead them to exclude OSA sufferers from certain roles ‘on health safety grounds’. Talking to specialists and consultants reveals how reluctant many of their patients are to reveal to their employers that they have had an OSA diagnosis. There is undoubtedly a lot of prejudice and misinformation in the workplace about this issue, and about fatigue and sleepiness generally – which, of course, goes a lot wider than OSA. ‘Caff napping’, as an essential coping mechanism in the workplace, (especially for older workers who make up a bigger proportion of the workforce these days) ought, for example, to be a widely understood and accepted coping mechanism, not a quirky outlandish idea.

If you have problems in getting enough good quality sleep, ‘don’t sleep on it’ (excuse the pun) – talk to your doctor and get help.

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