Mortality Due to Nervous System Diseases

Key Messages

Putting mortality due to nervous system diseases in context

Diseases of the nervous system accounted for about 5 per cent of all deaths in Canada (12,037 deaths) in 2011—the latest year of published data.¹ There are many types of nervous system diseases, including bacterial meningitis, Parkinson’s disease, Alzheimer’s disease, Huntington’s disease, multiple sclerosis, and epilepsy. More than half of the deaths due to nervous system diseases in Canada are due to Alzheimer’s disease, and almost 20 per cent are due to Parkinson’s disease.² While Alzheimer’s and Parkinson’s are both diseases of the nervous system, they are very different. Alzheimer’s disease is a fatal, degenerative disease that destroys brain cells, while Parkinson’s disease is a slowly progressing disease that causes people to lose control over their muscles. Although the causes of both diseases are unclear, they typically affect the elderly.

Mortality rates due to nervous system diseases must be put into perspective. Given that most of these deaths are due to Alzheimer’s, a disease that affects the elderly, regions with lower life expectancies may actually see a low number of deaths due to nervous system diseases, simply because the population is dying prematurely from other causes.

How do the provinces and territories rank relative to Canada’s international peers?

N.W.T. and Nunavut are the top-ranked on this report card in Canada, with a three-year average mortality rate due to nervous system diseases of less than 20 per 100,000 population. Both territories score an “A” and rank just behind Japan, the top performer with a mere 10.3 deaths per 100,000 population due to nervous system diseases between 2009 and 2011. Germany, Austria, and the Netherlands are the other top-ranked peer countries with “A” grades.

Canada ranks 12th among the 16 peer countries and scores a “B” grade. Between 2009 and 2011, an average of 35.2 Canadians per year died per 100,000 population due to nervous system diseases. All provinces earn “B” grades, with New Brunswick, Newfoundland and Labrador, Nova Scotia, and Quebec ranking below the Canadian average. Quebec ranks third-worst overall, with an average annual mortality rate of 45 deaths per 100, 000 population. Yukon also scores a “B” and ranks below the Canadian average with 40.1 deaths per 100,000 population due to nervous system diseases. Finland is the only region to earn a “D” grade, with an average mortality rate of 83.9 deaths per 100,000 population—more than one-and-a-half times higher than the mortality rate of the second-worst performer, the United States.

Almost all of the regions score “B” grades on this indicator because Finland is an outlier. If we exclude Finland, most of the provinces and Canada become “C” performers on this indicator, while Yukon, Nova Scotia, and Quebec earn “D” grades.

How do the provinces and territories perform relative to each other?

N.W.T., Nunavut, and British Columbia have the lowest mortality rates due to nervous system diseases in Canada, while Quebec and Nova Scotia stand out as the worst performers on this indicator. There is a large discrepancy between the top and bottom performers, as the rate of mortality from nervous system diseases in N.W.T. is almost three times lower than the rate in Quebec.

Why do N.W.T. and Nunavut rank so high?

The reason N.W.T. and Nunavut score so well on mortality due to nervous system diseases might be same reason they score so well on mortality due to heart disease and stroke. Like heart disease and stroke, nervous system diseases usually occur later in life. Life expectancy is only 71.8 years in Nunavut and 77.1 years in the Northwest Territories. Only 3.5 per cent of Nunavut’s population and 6 per cent of N.W.T.’s population is 65 years and older—much lower than the national average share of the population in this age range, 15 per cent.³ With the highest rates of mortality due to cancer and respiratory diseases in Canada, coupled with the high suicide rates, Nunavut and N.W.T. residents may not live long enough to suffer from Alzheimer’s and Parkinson’s disease.

Do the rankings change much when looking only at mortality due to Alzheimer’s disease?

The rankings on mortality rates due to Alzheimer’s disease mirror the overall rankings on mortality rates due to nervous system diseases. Japan remains the top performer, while N.W.T. and Nunavut have the lowest Alzheimer’s mortality rates in Canada. About 2.7 people per 100,000 population died per year as a result of Alzheimer’s disease in N.W.T. between 2009 and 2011, significantly below the Canadian average of 18.6. Nova Scotia and Quebec rank at the bottom on mortality due to Alzheimer’s. From 2009 to 2011, an average of 26.7 people per 100,000 population died per year as a result of Alzheimer’s disease in Nova Scotia—just a little higher than the Quebec figure. Only the U.S. and Finland fared worse than these provinces.

B.C. fares worse on mortality due to Alzheimer’s, placing 14th among the 29 comparator regions—much lower than its 7th place finish on overall mortality rates due to nervous system diseases.

Is Alzheimer’s disease preventable?

The most common risk factors for Alzheimer’s are age and family history. Since these are normally out of an individual’s control, it was thought that Alzheimer’s is inevitable for some people. But research is now beginning to reveal clues about other risk factors that people may be able to influence through general lifestyle and wellness choices.

For example, there may be a strong link between serious head injury and future risk of Alzheimer’s, especially when trauma occurs repeatedly or involves loss of consciousness. As well, growing evidence suggests that the risk of developing Alzheimer’s appears to be increased by any condition that damages the heart or blood vessels.⁴ In fact, it is possible that up to half the cases of Alzheimer’s disease worldwide may be the result of seven key risk factors: diabetes, high blood pressure, obesity, smoking, depression, cognitive inactivity or low educational attainment, and physical inactivity.⁵ A healthy lifestyle that includes healthy eating, maintaining a healthy weight, taking part in regular physical activity, maintaining normal blood pressure and cholesterol levels, and participating in activities that involve socializing and stimulating brain activity can help reduce the chance of developing Alzheimer’s disease.⁶

It is a common misconception that a person can’t die from Alzheimer’s disease. However, once a person reaches the mild or severe stage of the disease, the brain has deteriorated enough that normal activities become extremely difficult. This can lead to a lack of self-awareness and even a prolonged time in bed being cared for by a caregiver.⁷ As a result, Alzheimer patients are unable to provide themselves with proper nutrition, putting them at risk for other life-threatening diseases. Typically, multi-organ failure is the cause of death in Alzheimer patients, caused by complications due to heart attacks, strokes, and lung infections, among others.⁸

What is being done to address Alzheimer’s disease in Canada?

Life expectancy is close to 80 years in most regions of the country, and age is a leading risk factor of Alzheimer’s disease. With the aging Canadian population, Alzheimer’s is expected to become more widespread in the coming years. And with lifestyle now considered a risk factor, even more Canadians could potentially suffer from the disease.

In 2011, the Canadian government announced $8.6 million for new research on Alzheimer’s disease, with the goal of better understanding the disease to develop effective strategies for its prevention, early diagnosis and treatment.⁹ It has been recommended that simple things like early intervention, services that allow people to access treatment early, and workplace support initiatives can make a significant difference.¹⁰

More recently, Health Canada announced it will work with all provinces and territories to develop a national strategy to fight dementia. Currently, Canada is the only G7 nation without a national dementia strategy. In September 2014, the federal government launched the Canadian Consortium on Neurodegeneration in Aging, providing $31.5 million over five years in funding. The consortium will focus on research in three areas:

Footnotes

1    Statistics Canada, CANSIM table 102-0526, Deaths, by Cause, Chapter VI: Diseases of the Nervous System (G00 to G99), Age Group and Sex, Canada (accessed October 28, 2014).

2    Ibid.

3    Statistics Canada, CANSIM table 051-0001, Estimates of Population, by Age Group and Sex for July 1, Canada, Provinces and Territories (accessed October 28, 2014).

4    Alzheimer’s Association, Risk Factors (accessed October 28, 2014).

5    D. E. Barnes and K. Yaffe, “The Projected Effect of Risk Factor Reduction on Alzheimer’s Disease Prevalence,” The Lancet Neurology 10 no. 9 (September 2011), 819–28.

6    Alzheimer Society of Canada, Risk Factors (accessed October 28, 2014).

7    National Institute on Aging, Alzheimer’s Fact Sheet, July 2011.

8    Agingcare.com, Why Do People Die From Alzheimer’s Disease?(accessed October 28, 2014).

9    Canadian Institutes of Health Research, Government of Canada Takes Action on Alzheimer’s Disease, news release, January 28, 2011.

10    Mental Health Commission of Canada, Making the Case for Investing in Mental Health in Canada, 2013.

11    Government of Canada, Harper Government Invests in National Initiative to Tackle Dementia, news release, September 10, 2014.