SAN JUAN, P.R. — Not all older patients with dementia are dangerous drivers, making individual assessments of fitness to drive crucial for road safety, Dr. John C. Morris said at the annual meeting of the American Association for Geriatric Psychiatry.

It's no surprise that increasing dementia severity is a risk factor for unsafe driving. About 30% of demented people continue to drive. “We know that all demented drivers—at some point in the course of their dementia—will become unsafe,” said Dr. Morris, professor of neurology at Washington University, St. Louis.

Demented drivers have a twofold increased risk of crashing, compared with age-matched nondemented individuals. “In particular, they're at increased risk of fatal crashes,” Dr. Morris said.

Despite the potential danger, few older adults with dementia want to stop driving. “It's no surprise that older adults do not want to relinquish driving,” he said. Driving is a crucial means of transportation for many older adults—losing the ability to drive means losing autonomy. Without the ability to drive, older adults are at greater risk for social isolation and depression.

For many older adults, the issue of fairness also comes into play. They don't believe it is fair to have to give up driving when they have never had an accident.

“It's very important for older adults—if they are safe to drive—to be able to continue to do so,” Dr. Morris said. As a starting point, ask not only the patient but also family and caregivers about problematic driving behaviors whenever you evaluate an older adult. In particular, ask about the following unsafe behaviors that are typically exhibited by older adults with dementia:

▸ Failing to stay in their lane or to maintain proper distance.

▸ Driving at improper speeds (too fast or too slow).

▸ Ignoring or failing to comprehend road signs.

▸ Failing to signal, check traffic, or react to other drivers.

▸ Becoming lost.

▸ Having accidents, even “fender benders.”

▸ Receiving citations.

Driving simulators provide a safe testing environment and can help determine whether a person with dementia is safe on the roads.

Road tests, however, may be the standard by which other evaluation methods are measured, Dr. Morris said. These tests provide a reliable, direct measure of a person's driving ability but require special equipment and can be costly.

Finally, there is physician judgment based on information from the patient and family, cognitive measures, and physical examinations. Physicians actually do a fairly good job of evaluating a patient's ability to drive safely, Dr. Morris said. According to one study, physicians are accurate roughly three-quarters of the time in determining whether a person has the ability to drive safely (J. Am. Geriatr. Soc. 2005;53:94–8).

Age alone appears to be a risk factor for unsafe driving as well. Studies indicate that periodically monitoring older patients for driving ability is important. At-risk drivers should be reevaluated about every 6 months.

Here's the approach that Dr. Morris and his colleagues at Washington University's Alzheimer's disease research center use when dealing with the issue of dementia and driving:

▸ Routinely ask the patient and family members if the patient is driving and, if so, about any problems or risks.

▸ Assess any comorbid factors, such as medications and visual impairment.

▸ If the patient with dementia wishes to drive and reportedly can do so safely, require confirmation with a road test.

▸ If the patient performs safely on the road test, allow continued driving until a follow-up road test is done in 6–12 months.

▸ If the patient is determined to be an unsafe driver following a road test, initiate driving cessation.

“The most difficult part is, how do we get an older person to stop driving?” Dr. Morris asked. Appealing to the older driver's judgment usually does not work, but it is very important to maintain the patient's dignity during this process, he said. Going over with the patient and family the reasons why he or she should stop driving is sometimes helpful. “It has more weight coming from a physician,” said Dr. Morris, who also gives his patients a written reminder—a prescription—that they may not drive.

The family has to be involved in enforcing the decision. It's also important that the family work to provide an alternative means of transportation for the patient. In extreme situations, when the patient is determined to continue driving, the family may have to consider simply selling the car.

Dr. Morris recommended these Web sites for more information about older drivers or drivers with dementia:

▸ www.ama-assn.org/go/olderdrivers

▸ www.alz.org

▸ www.nhtsa.dot.gov

Monitor Driving Ability in Persons With Dementia : Ask the patient and family about specific driving behaviors, and consider vision, medications, and age.