Institute for Transport Studies (ITS)

Sleepy drivers - the underlying mechanisms

SupervisorsDr Samantha Jamson, Dr Mark Elliott (Consultant Respiratory and General Physician, Leeds Teaching Hospitals)

Obstructive sleep apnoea (OSA) is the most common sleep-related breathing disorder and is characterized by repetitive narrowing or collapse of the airway during sleep. This results in excessive daytime sleepiness. Sufferers are approximately 7 times more likely to be involved in a road crash, compared to those who do not suffer. Assessing fitness to drive is difficult and in most cases recommendations are based on rather subjective criteria such as a patient's account and physician opinion. Getting the decision to allow a patient to continue driving wrong can have major implications. Being denied a licence would be a major inconvenience; for others it may cost them their job. Conversely, allowing someone to drive who then causes an accident by falling asleep at the wheel may be a disaster for them and others.

Refining risk assessment would be a real asset to clinicians working in this area. Driving simulators, used in research settings, have shown that patients with OSA perform worse than control subjects, but we haven't been able to establish the exact cause of this poorer performance. Are sufferers exhibiting normal signs of sleepiness, resulting in poorer lane discipline and delayed reaction times? Or are there additional deficits that are associated with long-term sufferers such as cognitive decline and attention deficits which affect driving performance?

The aim of this PhD project (would also be appropriate for medically qualified graduates who wished to do an MD) is to first collate the literature in the field of driving performance and OSA. This will involve a critical review of the sometimes contrasting results obtained in driving studies, to appreciate methodological and procedural nuances.

In-depth studies will then be undertaken, using a driving simulator, to establish how those patients with OSA may differ from control patients in terms of subtle measures of driving performance on a range of driving tasks (simple lane keeping to more complex decision making at urban junctions). Ultimately, the aim of the PhD (or MD) is to provide further understanding as to how patients' fitness to drive might be assessed in a robust and sensitive manner.

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