Driving Is Safe For Some With Alzheimer's

Many people in the early stages of dementia — such as Alzheimer's — can continue to drive safely as long as they are monitored closely. That is the contention of a group of researchers in the United Kingdom, whose review of the clinical evidence led them to conclude that with frequent assessment of driving skills, the risk of accidents among older people with dementias was acceptably low for up to three years after diagnosis.

Geriatrician Desmond O'Neill, M.D., who co-wrote the analysis, tells WebMD that mandatory screening of older drivers based on age alone is both unnecessary and ageist. The analysis appears in the June 20 issue of BMJ, the British medical journal.

"Older drivers as a group are the safest drivers on the road," he says. "The very high-profile incidents involving older drivers have led to unwarranted prejudice against them."

The most high-profile case involved a 2003 crash in California at the Santa Monica farmers market. Ten people died and 45 others were injured when an 86-year-old man crashed through a barricade and drove for nearly two blocks before coming to a stop. The driver, who had a valid license, later explained to police that he tried to stop the car but may have hit his gas pedal instead of his brakes.

Ironically, another Santa Monica incident, occurring seven years earlier, led to nationwide efforts to mandate license renewal testing for older drivers. In November 1998, 15-year old Brandi Mitock was killed while crossing an intersection by a 96-year old driver with a history of dementia, strokes, and other health problems. The man also had a valid driver's license but hadn't taken a road test since he had first gotten the license in 1918, according to news reports.

Several states require older drivers to renew their licenses in person, instead of by mail. Some states require elderly people to renew their licenses more often than other drivers or to pass vision tests when they renew them. In the United Kingdom, drivers are required by law to inform motor vehicle licensing officials of a diagnosis of Alzheimer's or some other dementia. This is not the case in most U.S. states, but a researcher who studies the issues faced by older drivers believes it is a good idea.

Dennis McCarthy, Ph.D., is co-director of the National Older Driver Research and Training Center (NODRTC) at the University of Florida in Gainesville. McCarthy says a "baseline" assessment administered by a specially trained driving instructor should be performed immediately following a diagnosis of Alzheimer's or other dementia, with similar assessments performed every six months after that.

"This way you know when a person's Alzheimer's disease has affected their driving, as it eventually will," he says. "But just because someone is diagnosed with Alzheimer's that doesn't mean they can't drive safely."

Like O'Neill, McCarthy believes that, as a group, older drivers are among the safest drivers on the road, despite highly publicized statistics suggesting otherwise. He concedes that elderly drivers have more accidents per miles driven than any other age group, but he says the statistic is misleading. "A 40-year old may drive 15,000 miles a year on the turnpike, which is the safest roadway, while older folks tend to drive far fewer total miles and drive mostly on surface streets, which are statistically more dangerous."

Older drivers tend to police themselves by restricting their own driving to familiar situations, he says. "They might stop driving at night or drive only when the traffic is light, and they tend to stay close to home," he says.

He adds that mandatory, age-based testing of older drivers has not been proven useful or cost-effective for identifying those who shouldn't be behind the wheel, nor have efforts to force doctors to report patients with medical problems that could affect their driving.

"We haven't come up with very good clinical tests that predict driving performance, and physicians don't necessarily know how to tell if a patient should be driving or not," he says.

Finally, McCarthy says, older people in the U.S. desperately need better ways to get around so they can remain independent once they stop driving. There are 19 million drivers over age 70 in the U.S., and by 2024 one in four drivers will be age 65 or older, according to NODRTC. "We need acceptable alternatives to driving so that it isn't such a devastating consequence when an older person loses their license," McCarthy says.

By Salynn Boyles
Reviewed by Louise Chang, M.D.
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