Risk of Death in Canada : What We Know and How We Know It
by Simon P. Thomas (Author), Steve Hrudey (Author)
Paperback: 280 pages Publisher: The University of Alberta Press (Dec. 1, 1997)

Reviewed by Ron Truman, Regulatory Solutions Group

Actuaries can tell you how many Canadians are going to die next year; hit men can name a few names. But until recently, there’s been no middle ground — information that has a personal meaning for a wide variety of Canadians — about the risk of dying in the next 12 months.

University of Alberta environmental health sciences professor, Dr. Steve Hrudey, who led a study of 60 years of Canadian death data, can fill part of that gap.

For instance, Hrudey asks, “Would you buy a lottery ticket, a chance on the 6/49 draw if you were guaranteed one chance in 200 of winning? You bet. Unfortunately, if you are a male Canadian between the ages of 50 and 54, one in 200 is your chance of dying in the next 12 months.”

That’s got to be debilitating news for a 50-ish man on the cusp of deciding whether to keep putting in overtime at work and climbing the ladder, or just cutting loose.

Hrudey has more bad news. Canadians brag that their life expectancy keeps going up and up. We puff with pride when the United Nations mentions it as one of the reasons why Canada is the world’s best place to live.

But Hrudey and his fellow researchers point out that we haven’t truly solved the problems of old age and actually extended the life span of the Canadian human.

What we have done is reduce the number of preventable deaths. Longer life expectancy means we have more companions the same age as ourselves as we get older, not that the upper limits to human life span have been extended in Canada.

But if you have the urge to grin in the face of the grim reaper, Hrudey suggests you smile at your spouse. In Canada, married people, both men and women of all age groups, have substantially lower death rates than single, divorced or widowed individuals. Hrudey, after analyzing the data about married people, says this consistent pattern suggests personal social factors like having a spouse are “very determinant in reducing mortality.”

Hrudey’s research has produced one thing for Canadians not to worry about: a cancer epidemic caused by modern technology. “Contrary to popular belief,” he says, “we are not experiencing an epidemic of cancer. Cancer mortality rates for women — taking into account the increasing size and average age of the population — have not increased, despite a sharp increase in lung cancer mortality. The overall increase observable for men is primarily caused by lung cancer, which is attributable to smoking.”

And if you are one of the Canadians who have been inflating your grocery bill by consuming only “all natural” products purchased in health food stores to avoid the risks of cancer from synthetic chemicals, Hrudey recommends saving your money. “There is no evidence in support of the popular thesis regarding synthetic chemicals and cancer in actual mortality rates in Canada,” he says.

So what can Canadians do to reduce their risk of death besides being married? Hrudey says, “Don’t smoke. The research shows smoking is a preventable cause for approximately 42,000 deaths per year in Canada from cancer, heart and respiratory diseases. That’s over 20% of all deaths in any year.”

But you can’t modify the really big determinants that affect your risk of death because they are pretty well pre-determined. They are sex and age. Females are always at less risk of death than males of the same age.

But the steadily increasing life expectancy for both sexes in Canada isn’t as remorselessly pro-female, Hrudey says. “Life expectancy at birth for Canadian women increased by about 15 years for a woman born in 1990 compared with one born in 1930,” he said. “But in that same time period, the increase was only about 8 years for women who survived to the age of five and only about five years for women who survived to the age of 25.

“We concluded that much of the improvement in female life expectancy has resulted from reduction in overall infant mortality and reduction in female mortality during childbirth, both major causes of death until the 1970s. That means those who expect our world of modern medicine will continue to extend life expectancy are likely to be disappointed.”

The most important factor determining our probability of death in any given year is first our age, then our sex. “Our first year is our most dangerous year of life until we reach 55,” Hrudey said. “From 20 to 24, males are three times more likely to die in any given year than are females.

“Although motor vehicle fatalities are an important factor here, the greatest risk of death for males in this age group is from suicide.

“By the time a man reaches 55, his annual chance of dying from any cause in Canada becomes one in 120. As you get older, your annual risk of dying gets higher until beyond 90 it increases to over one in four.”

Although scientists can record and analyze what causes of death exist for Canadians as a group, the odds of dying, says Hrudey, are like the odds in a game of chance, like taking one, six-sided die and rolling it. You can’t predict which number will actually appear.

We worry more about the risk of death than our ancestors did, says Hrudey. “A hundred years ago, Canadians faced enormous obstacles to survive the rigours of our climate and wilderness and the scourges of infectious disease,” he said. “Recently, we have experienced a transition from acute diseases as major causes of death to the dominance of chronic diseases such as cancer and cardiovascular disease.”

Hrudey and his research associate, Simon Thomas, began researching risk because not all risk estimates are equally valid.

Some are solidly based on reliable data available, for example, from autopsies. Other risk estimates, far less certain, are inferred from epidemiological studies on selected samples of human populations or predicted from toxicology experiments with animals.

As a result the public, the media, and health professionals often encounter a fog of confusing and conflicting information when seeking answers about risk.

The research is summarized in a 270-page book titled Risk of Death in Canada: What We Know and How We Know It. With more than 150 figures and tables, it is a reference work designed for health professionals rather than a citizen’s guide to health risk.

Despite the overall interest in risk in our society, the book has caused some curious reactions. Says Hrudey: “Some people aren’t comfortable with the subject. Perhaps that’s the reason my own university bookstore displayed it for less than a week in their new book window in the hospital.”