8.1.1 Evidence of crash risk
Studies have shown an increased rate of motor vehicle crashes of between two and seven times that of control subjects in those with sleep apnoea.1 Studies have also demonstrated increased objectively measured sleepiness while driving (electro-encephalography and eye closure measurements) and impaired driving-simulator performance in people with confirmed sleep apnoea. This performance impairment is similar to that seen due to illegal alcohol impairment or sleep deprivation. Drivers with severe sleep disordered breathing (respiratory disturbance index greater than 34) may have a higher rate of crashes than those with a less severe sleep disorder.
Those with narcolepsy perform worse on simulated driving tasks and are more likely to have vehicle crashes than control subjects.
In commercial vehicle drivers fatigue from sleep deprivation due to shift work also contributes to the risk of a crash. Fatigue should be managed as per the NTC Guidelines for Managing Heavy Vehicle Driver Fatigue (refer to <www.ntc.gov.au>).