Bob Hogarth was a big, gregarious man with a playful twinkle in his blue eyes. But when he was told at the age of 83 that he could no longer drive, he became angry and bitter.

"He was mad at everyone for [him] not being able to drive: friends, family, and the doctor who told him he couldn't drive any more," says Marion, his wife of 63 years.

For someone who had driven since he was 15, it was a blow to his ego and freedom.

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"The denial was unbelievable. We had to hide the keys on him. If my mom wasn't around, he'd try to steal the car," says son Tom, a Windsor, Ont., lawyer. "For his generation, it was always the man who did the driving."

Tom realized his father had lost his driving touch when he spotted the Grand Marquis in the garage one day, "and it was totally banged up." His dad never did tell him what happened.

A senior's deteriorating skills at the wheel can have a devastating effect on their quality of life and self-esteem. Without their car, the senior fears a new reality of isolation, loneliness and inconvenience.

Like many people would, Tom waited and watched his dad until he could no longer avoid taking action.

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Hogarth's experience is an issue baby boomers can't swerve to avoid. Of Canada's more than five million seniors (65 and older), 28 per cent are 80-plus. Mandatory driver screening begins at 80 in most provinces, a sensitive topic made more so with Ontario's new cognitive test added to the existing medical and vision tests, beginning April 21.

But not everyone agrees with mandatory screening. The Canadian Association of Retired Persons (CARP) assails the age discrimination, and claims the testing is arbitrary and – while improved since announced – not an accurate measure of cognitive ability.

CARP prefers that every driver get remedial testing periodically, regardless of age, says Susan Eng, vice-president for advocacy. Distracted and bad driving is distributed across all ages, CARP contends. "In all of Canada, there are 1.3 million people 80 and over. You're not going to tell me it's legitimate to tar them all with the same brush."

Statistics support part of CARP'S position. In 2010, there were 3.5 million drivers age 65 and older in Canada. Besides young men, reports Statistics Canada, drivers 70 and older have the highest rate of accidents. They're also more vulnerable to being killed in a collision.

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Prescription side effects, illnesses such as diabetes and dementia, physical disabilities, impaired vision and other indignities of aging all compromise driving ability.

No one relishes taking away someone's keys. Laura Diachun deals with this on a weekly basis in her practice as a geriatrician at Parkwood Hospital in London, Ont. "I feel really guilty and sad at times doing this to people, but it's the law," she says.

Mild cognitive impairment and dementia is common among those 75-plus, she says; 17.5 per cent have dementia and 15 to 20 per cent have mild cognitive impairment.

Even so, she's not convinced the new screening is an adequate way to determine cognitive ability.

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"I do think we need to change the way we screen older drivers. I think [the new screening] is a step in the right direction, but I think we are nowhere done yet," she says.

A simple cognitive test at the family doctor ended Hogarth's driving days. The doctor took the role of bad cop, telling son Tom, "I'll tell him so he won't blame you."

In spite of that, as soon as they left the office, Hogarth told his son, "Thanks a lot for taking my licence away," says Tom, chuckling at the memory.

Diachun knows that scenario well. "No matter how cognitively impaired an adult is, they always remember the face of the person who said they can no longer drive."

Lisa Monforton begins her twice-monthly column today.

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