Medical conditions are a relatively minor risk factor in road traffic crashes, being reported as a contributory factor in 7% of fatal crashes and 2% of all reported crashes. However, their prevalence as a factor may be under-estimated in road accident data due to the difficulties in assessing whether those involved had a medical condition, and if so, whether it contributed to the crash or its consequences. Driving is a complex activity that requires a combination of physical and cognitive skills that can be adversely impaired by a wide range of fitness and health conditions. Drivers are personally legally responsible for ensuring that they are fit to drive, and informing the Driver and Vehicle Licensing Agency (DVLA) if they develop a condition that affects their fitness to drive. The DVLA sets minimum medical standards and rules for all drivers, including conditions that must be reported to the DVLA. The medical rules for Group 2 drivers (drivers of large vehicles over 3,500kgs, minibuses and buses) are more stringent than the rules for Group 1 drivers (cars and motorcycles). The DVLA assess over 700,000 fitness to drive cases each year, of which around 49,000 result in a licence being revoked or refused. Dementia impairs driving ability and can increase crash risk. However, in the earlier stages of the disease drivers often compensate by, for example, reducing or changing the type of driving they do. Epilepsy is rated as a high-risk condition for crash involvement. Drivers with diabetes have a higher crash risk than those without diabetes, and the risk is even higher for diabetic drivers who are not taking medication for the disease. Drivers with either insomnia or obstructive sleep apnoea syndrome have a significantly increased crash risk compared with controls. The research evidence is inconclusive regarding the association between cardiovascular disease and crash risk. Heart disease is the most common cause of sudden death at the wheel, but not of acute collapses at the wheel (diabetes and epilepsy). Evidence is inconsistent regarding musculoskeletal conditions and crash risk but cognitive symptoms of multiple sclerosis are associated with increased crash risk. There is no significant association between hearing impairments and crash risk. (Author/publisher)
Abstract