Miss Daisy driving

When's the right time for seniors to hang up the car keys?
Striking a fine balance

By Wendy Banks

Marge Winters, 71-years-old, seems sharp enough as she makes polite small talk with the young mother seated next to her in the doctor's waiting room. But her daughter, Jill, is concerned. "Last week, on our way back from the post office, she drove straight through a red light," she confides to their family doctor. "She almost got us killed � and it wasn't the first time."

It's news to the doctor. Mrs Winters is basically healthy, has an active social life, and has never seemed less than fully 'with it' when she's seen her. But the daughter's admission means that she's legally obliged to report Mrs Winters to the Ministry of Transport. She could lose her license, and with it, a big part of her independence. It's a fine balance. How would the loss of mobility affect Mrs Winters' health? On the other hand, how great a risk does she pose to the public if it turns out she's showing early signs of dementia?

"Older people don't crash because of age per se," says Dr Malcolm Hing, a geriatric medicine specialist at the University of Ottawa. "They're more likely to develop medical conditions that potentially impact upon their driving ability, which then leads to higher crash rates." Although conditions such as arthritis, diabetes, cardiovascular disease and, of course, poor eyesight can cause crashes, the most dangerous health problem for older drivers is dementia.

"Most people who develop these conditions � say, eyesight difficulties � self-restrict, meaning they reduce their driving to whatever they feel comfortable with," says Dr Hing. "However, with most dementing illnesses, especially Alzheimer's disease, they lack insight into their cognitive deficits." It's hard to say how common this problem is, but one study suggested that 20% of drivers over the age of 80 who were renewing their licenses, suffered from cognitive problems.

OFF THE RADAR
These patients can slip under their family doctor's radar pretty easily, says Dr Hing. "Multiple studies have shown that most family physicians are unable to recognize persons in their practice who have mild dementia," he explains. "It's very subtle � they tend to hold on to their social skills, so in the brief office visit that the patients have with their physicians you'd never be able to pick it up. The usual way that family physicians clue into the fact that driving may be an issue with the person is that family members report it."

Which is where legal troubles rear their ugly heads. In most provinces in Canada, physicians are legally mandated to report to the Ministry of Transport all drivers they believe to have a medical condition that may impact on their driving. The problem is, they have no accurate measuring tools to help them evaluate these people � they have to rely on their clinical judgment. To complicate things, the American Academy of Neurologists has recently released a consensus statement that anyone with moderate to severe dementia should not be driving, but evidence suggests that people with mild dementia can be safe drivers.

Dr Hing, caught in this quagmire in his own practice, decided to take action. He and two of his colleagues, Dr Shawn Marshall, a physical medicine and rehabilitation specialist, and Dr Frank Molnar, a geriatrician, applied for a five-year research grant from the Canadian Institutes of Health Research to determine once and for all how to assess the risks posed by older drivers. The result is CanDRIVE, the Canadian Driving Research Initiative for Vehicular safety in the Elderly, a national, multidisciplinary research group interested in all aspects of the safety of older drivers, from screening to alternative transportation to re-education.

They're conducting a large prospective cohort study, enlisting 1,000 to 2,000 older drivers, performing an annual battery of tests on them, and following them for five years. They're hoping to develop a comprehensive and reliable assessment tool for family doctors across the country.

In the meantime, what's a doc to do? Don't despair � Dr Anna Byszewski, an Ottawa geriatrician, has developed A Driving and Dementia Toolkit, a practical approach for assessing older drivers with dementia. It's available for download on the Regional Geriatric Assessment Program of Ottawa website at www.rgapottawa.com.

For more information on CanDRIVE,
visit www.candrive.ca