This Austroads Research Report was published in September 2011. The study aimed to understand the extent to which a pre-existing medical condition or acute medical event was a contributing factor in crash causation. The study involved examination of the circumstances surrounding drivers, riders, cyclists and pedestrians involved in casualty crashes on public roads in South Australia who were admitted to the Royal Adelaide Hospital over the three year period from January 2008 to December 2010.
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This study has shown, through detailed consideration of the medical records of road users admitted to hospital following a crash, that medical conditions are associated with the occurrence of 11-12% of their crashes.This is a larger proportion than reported in other studies.
Loss of consciousness from undetermined causes, seizures, mental illness and deliberate suicide attempts were identified as being important. Highly elevated blood alcohol levels were found particularly in persons with alcohol dependence. Alcohol played a role for those involved in the crash as a result of mental illness and deliberate suicide attempts but did not play a role for other medical condition cases. The occurrence of multiple co-morbid medical conditions increased with increasing age with a corresponding increase in being involved in a crash as the result of a medical condition or acute medical event.
The findings of this study have implications for licensing authorities and for the management of licence holders with medical conditions by the treating medical personnel. The study findings also have implications for road safety practitioners in developing strategies to address an aging population.