Background: Although alcohol and recreational drugs are recognized as significant risk factors for motor vehicle collisions (MVC), the contribution of sleepiness alone is less clear. We therefore sought to identify the contribution of sleepiness to the risk of a MVC in injured drivers, independent of drugs and alcohol.
Methods: A prospective questionnaire and examination of sleep-related risk factors in drivers surviving MVC in a major hospital-based trauma centre was carried out.
Results: Forty of 112 injured drivers screened were interviewed, of whom approximately 50% had at least one sleep-related risk factor, 20% having two or more. Of the MVC deemed sleep-related by questionnaire, only 25% were identified by the Australian Transport Safety Bureau definitions. Shift work was the greatest sleep-related factor identified contributing to MVC.
Conclusion: Sleepiness, particularly related to shift work, needs to be emphasized as a risk factor for MVC. Australian Transport Safety Bureau definitions of sleep-related MVC are too lenient.