A University of Iowa study finds drivers who have been diagnosed with early Alzheimer’s disease make more serious errors behind the wheel than their elderly counterparts who have no sign of the illness.
Jeff Dawson, a U-of-I professor of biostatistics in the College of Public Health, says they studied more than 150 elderly drivers, about 40 of whom had early Alzheimer’s.
Dawson says: "They made about 25% more errors overall but in particular, the lane observance errors, things like crossing the center line of going off the shoulder, were about 50% more common."
Of the 76 error types that were monitored, he says the drivers with Alzheimer’s were about twice as likely to commit the more serious errors as their healthy counterparts.
Dawson says one possible outcome of this study would be to develop a type of test older drivers might be required to take upon renewing their licenses. In Dawson’s words, it’s a very emotional issue. "You have to balance out the safety of the driver and the other people on the road with mobility and independence, especially in a state like Iowa where the rural areas tend not to have public transportation," Dawson says. "Taking someone’s car keys away can mean a real lack of independence and a burden."
There were three types of tests — a cognitive pencil-and-paper test, one in a driving simulator and one on the road in a car outfitted with instruments and four video cameras. On the cognitive test, Dawson says the outcome was unexpected for the people with early signs of Alzheimer’s.
"They did better than average on those," Dawson says. "They often had about the same safety profile as those without Alzheimer’s disease, so that shows that if you have Alzheimer’s disease, right at the beginning, it’s not immediately a cause to no longer drive but it’s something that needs to be monitored over time." The U-of-I research was published in Neurology, the medical journal of the American Academy of Neurology.