Driving and Dementia
"Mrs. Jones" looked like any kid's grandmother. She was in her 60s, lucid and well-spoken. When asked by the driver rehabilitation specialist (CDRS) why she thought her daughter had brought her in for evaluation, Mrs. Jones intimated that her family was concerned but had no need to be.
Then the CDRS asked Mrs. Jones a few questions. What month is it? (At the time it was November, but Mrs. Jones said October.) How many miles do you drive each year? (Though she said most of her driving took place on neighborhood roads, Mrs. Jones estimated she drove 100,000 miles per year.)
Simple puzzles designed to reveal mental function were similarly discouraging. The CDRS handed Mrs. Jones a piece of paper with a series of numbers and letters and asked her to connect them using a specific pattern – 1 to A to 2 to B, etc. Mrs. Jones couldn't do it.
The point? With older drivers, mental decline serious enough to impair safe driving is not always obvious to the naked eye.
While giving his address at the University of Wisconsin School of Medicine and Public Health's Wisconsin Alzheimer’s Institute annual conference in Madison last week, Dr. Meuser was careful not to condemn all older drivers.
"The majority (of older drivers) are safe and capable," he said. "But there is a minority experiencing dementia, and they must be monitored."
That's easier said than done, because "we have a curious system for licensing drivers in this country," Dr. Meuser said.
State departments of transportation are responsible for licensing drivers in the United States, and their standards and methods of evaluation vary as any state policy might. And most reporting mechanisms are voluntary, meaning that drivers are not legally required to prove that they are capable drivers as they get older.
People are living longer, too, so their driving lives are more likely to be encumbered by symptoms of dementia often undetected because stringent, consistent mechanisms are not in place.
"If you live long enough, you're going to outlive your driving expectancy," Dr. Meuser said. "But drawing these lines is difficult."
It all adds up to a potentially dangerous situation on the roads, and Dr. Meuser's research confirms his call for attention.
While at Washington University Dr. Meuser was involved in a study that measured the skills of drivers in their 70s by looking at their ability to obey traffic signs, turn, change lanes and maintain speed. The participants were divided into three groups according to their clinical dementia ratings (CDR). The control group had a CDR of zero, meaning they showed no evidence of dementia. The two test groups had respective CDRs of .5 (very mild dementia) and one (mild dementia).
The results? Whereas in the control group (CDR of zero) only three percent of the drivers were considered unsafe, 41 percent of drivers with CDRs of one – which is still considered mild – were found to be unsafe drivers.
"With dementia, retirement from driving is an inevitable endpoint," Dr. Meuser said. "The critical period is the very mild to mild stage," because those drivers may be unsafe without exhibiting any obvious signs of mental erosion.
Given the barriers to effective monitoring, Dr. Meuser acknowledged there is no easy prescription.
"We don't have a simple battery of tests that will say test (a driver's competence) or don't test," he said.
But he does believe unsafe drivers can be detected if people occupying unofficial channels – notably, family members and physicians – pay close attention.
Wisconsin, for example, is one of the states with no mandatory review process for older drivers. However, the Wisconsin Department of Transportation can request information about any driver who is suffering from a medical condition that may hamper his driving. The key is awareness, and that's where the family and physician can help.
"There are red flags," Dr. Meuser said. "Family reporting is huge. They are on the front lines. They'll notice."
And when they do, they should arrange for a physician evaluation. The results of that evaluation may compel the physician to submit a "Driver Condition or Behavior Report" to the DOT. That's the first step in restricting or revoking the license of an unsafe driver. In fact, under Wisconsin law, MDs, DOs (osteopaths) and advanced practice nurse prescribers are given the authority to recommend immediate cancellation of a driver's license based on the evaluation.
The ultimate objective, Dr. Meuser says, is not to castigate all older drivers as unfit for the road but rather identify the small number of people who shouldn't be driving, for their safety and the safety of other motorists and pedestrians.
Date Published: 11/11/2008