Traffic Crash History of Cognitively Impaired Drivers in Missouri

Driving is a complicated process whose consequences can be serious and irreversible if medical impairments affect key functional abilities. Dementia and cognitive decline from other etiologies (e.g., stroke, brain injury) can also impair driving abilities, so it is important to understand their potential consequences. The crash histories of 1,691 drivers from Missouri reported to state authorities from various sources in 2001 to 2005 as having cognitive impairment and 11,615 age- and gender-matched controls were compared. The results showed that about 30% of the cognitively impaired drivers had been in a crash in the 3 years before being reported to state authorities, compared with only 7% of controls in the same period. Cognitively impaired drivers who crashed were also found to be more often involved in multiple crashes [19.8% Alzheimer’s disease (AD), 21.5% cognitive impairment, 30.3% brain injury] than the controls (8%). Cognitively impaired drivers were in significantly more fatal and disabling injury crashes (4.7% AD, 4.3% cognitive impairment, 7% brain injury) than controls (2.7%). Earlier identification of cognitive impairment and intervention for driver fitness may reduce the frequency of crashes for older drivers. The challenges of those who turn out to be medically unfit to drive must be addressed with improved transportation support.