April 13, 2010 (Toronto) -- If a family member with Alzheimer's disease or other dementia is racking up traffic tickets, getting in repeated fender benders, or exhibiting road rage, it may be time to think about taking away the car keys.
About 4 million Americans have some type of dementia and nearly all will eventually have to give up driving, says Donald J. Iverson, MD, of the Humboldt Neurological Medical Group, Inc., in Eureka, Calif.
It’s one of the most wrenching decisions a family has to make, forcing the patient to face a loss of autonomy, Iverson tells WebMD. And there's no hard rule or simple test to tell when a person is poised to become a danger, he says.
In an effort to offer some guidance to patients and their families, Iverson and other experts convened by the American Academy of Neurology (AAN) recently combed through 6,000 studies and articles to arrive at new guidelines on dementia and driving.
The recommendations were released here at the AAN's annual meeting and simultaneously published online by the journal Neurology.
Crafting New Guidelines
The Academy's previous guidelines recommended that all people with mild dementia give up driving, Iverson says.
But recent studies present a conundrum, he says. "On the one hand, there is research showing people with dementia are up to 88% more likely to fail a driving test than people without dementia," Iverson says. "On the other hand, some studies show as many as 76% of people with mild dementia can pass an on-road driving test and can safely drive."
Faced with the conflicting research, the guidelines committee concludes that "patients with mild dementia should strongly consider stopping driving," he says.
The guidelines can help identify people at higher risk of unsafe driving, without unnecessarily restricting people who don't pose a danger, he says.
In creating the guidelines, the committee generally defined safe driving as being able to pass a road test. "It's not a perfect measure, but based on the evidence, it's the best we have," Iverson says.
Identifying Unsafe Drivers
One of the best ways to identify unsafe drivers, according to the guidelines, is a standard test called the Clinical Dementia Rating (CDR) scale. Administered by a doctor with input from caregivers, the CDR assesses people's memory and problem-solving skills as well as their ability to care for themselves.
Caregivers can be extremely helpful in identifying unsafe drivers -- but only if they're honest, Iverson says.
"If a caregiver says, 'I'm concerned,' or rates a patient's driving as 'marginal' or 'unsafe,' that really pans out," he says.
But studies show that caregivers who deem their loved one's driving as "safe" are rarely accurate, "probably because they are trying to protect the patient," Iverson says.
"And if a patient himself says their driving is fine, that doesn't help. In fact, the strongest evidence we found is that this doesn't correlate with safe driving," he says.
Warning Signs of Driving Problems
The guidelines say these are some of the warning signs caregivers should watch for:
- Accidents. Research shows that people who have had a crash in the past five years are more likely to have another accident, compared to people with mild dementia alone.
- Moving violations. One study showed that people over 70 who had two or more tickets in the past three years were more likely to have a crash than any other age group, including teenage boys, who recently held that spot.
- Driving less. "The magic number seems to be 60 miles a week. Driving less than that is associated with unsafe driving," although where you live and how frequently you typically drive factor in, Iverson says.
- Avoiding certain driving situations, such as driving at night or in the rain.
- Road rage. Research shows that aggressive or impulsive personality traits can be useful in identifying unsafe drivers, Iverson says.
Becoming lost on a familiar route may also be a warning sign, says David Knopman, MD, a spokesman for AAN who was not involved in writing the guidelines.
Getting lost once may mean nothing, he says. "But if a person arrives two hours late repeatedly with no good explanation or there are unexpected dents in the car, there may a problem, says Knopman, a neurologist at the Mayo Clinic in Rochester, Minn.
Caregivers and Doctors Take Charge
So is there anything a person with dementia can do to improve his or her driving skills?
Not really, Iverson says. One study showed that people over 85 who took an in-person test to renew their driving license slightly lowered their risk of being in a deadly crash. But otherwise there was no evidence supporting strategies such as driver training or licensing restrictions, Iverson says.
The bottom line, he says, is that even as dementia worsens, most patients are going to deny that they pose a hazard on the road. That places doctors and caregivers in charge.
Don't bring up giving up the car keys when a person is just recovering from the blow of being diagnosed with dementia, Iverson says.
"But over time, caregivers and doctors should begin the discussion," he says. "It's a process. And, it's not easy."
Doctors, patients, and caregivers must also know their state laws, because some states require that doctors report any medical conditions that may affect a patient's ability to drive safely.