Chapter 4
Health Outcomes
When considering health outcomes from cardiovascular disease (heart disease and stroke), mortality tends to receive the greatest attention due to the availability of the data. But since many individuals live with cardiovascular diseases, it is important to consider who develops it (incidence), who is currently living with it (prevalence), and the nature of their disabilities and the quality of their lives.
Incidence and Prevalence
Unfortunately, since the existing surveillance system for cardiovascular diseases in Canada relies on administrative physician billing, and hospitalization and mortality data, the incidence of the diseases (the rate of people developing cardiovascular diseases) is not routinely determined. In fact, few reports on the incidence of cardiovascular diseases in Canada exist.
Some sense of the prevalence of cardiovascular diseases (the proportion of the population with heart disease or stroke) can be obtained from Statistics Canada’s National Population Health Survey (NPHS) and, more recently, its Canadian Community Health Survey (CCHS). This approach is limited, however, by the fact that the collected data are self-reported and dependent not only on the individuals having already been diagnosed with heart disease by a physician, but also on their reporting this correctly in the survey.
In 2000, the prevalence of self-reported heart problems was low among men and women up to the age of 50 years (Figure 4-1). Prevalence increased after this age, with the increase much greater among men than women. By the age of 70 years, 1 in 5 women and 1 in 4 men reported having been told by a physician that they had heart problems.
Quality of Life
Heart disease has a major impact on quality of life. In 2000, 90.0% of the population without heart disease reported their health as being good, very good or excellent. The percentage was much lower among those with self-reported heart disease (51.0%) or stroke (36.8%). Among people with chronic diseases, those with stroke had one of the lowest percentages reporting good or better health.
In 2000, a high percentage of individuals who had had a stroke reported having activity restrictions and needing help with activities of daily living (Figure 4-3). The percentage was also high among those with self-reported heart disease, but lower than among those with stroke. Slightly more than one-quarter of individuals with either heart disease or stroke reported more than one disability day in the previous 14 days. Of those with heart disease, 16.0% reported being depressed during the previous 12 months, as did 18.4% with stroke. A much lower percentage of individuals without heart disease or stroke reported specific limitations in their lives.
Mortality
Leading Cause of Death
In 1999, cardiovascular diseases were the leading cause of death in Canada (36%) (Figure 4-4). Ischemic heart disease accounted for the greatest percentage of deaths (20%), of which half were attributable to acute myocardial infarction. Cerebrovascular disease (mainly stroke) accounted for 7% of deaths.
The percentage of all deaths due to cardiovascular diseases has decreased since 1987 by 14% among men and 16% among women (Table 4-1).
|
Table 4-1 Percent of Total Deaths Due to Cardiovascular Diseases by Sex, Canada, 1987-1999 |
|||
|
Year |
Men |
Women |
All |
|
1987 |
40.48 |
43.97 |
42.06 |
|
1988 |
39.47 |
43.42 |
41.26 |
|
1989 |
39.06 |
42.61 |
40.67 |
|
1990 |
37.34 |
41.21 |
39.12 |
|
1991 |
37.11 |
40.95 |
38.88 |
|
1992 |
37.12 |
40.72 |
38.78 |
|
1993 |
37.03 |
40.19 |
38.50 |
|
1994 |
36.35 |
39.75 |
37.94 |
|
1995 |
35.99 |
39.29 |
37.54 |
|
1996 |
35.93 |
38.84 |
37.32 |
|
1997 |
36.03 |
38.64 |
37.28 |
|
1998 |
35.34 |
37.53 |
36.40 |
|
1999 |
35.02 |
36.97 |
35.96 |
|
Source: Health Canada, using data from Mortality File, Statistics Canada |
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Among men of all ages, 35% of deaths in 1999 were attributable to cardiovascular diseases, while the percentage among women was slightly higher at 37% (Figure 4-5; Table 4-2). Among women, the percentage of all deaths due to cardiovascular diseases increased after the age of 50 years. In men, the percentage of all deaths due to cardiovascular diseases increased steadily after the age of 40 years.
In 1999, 78,942 deaths were attributed to cardiovascular diseases - 39,134 women and 39,808 men (Table 4-2). Ischemic heart disease accounted for 48.6% of these deaths among women and 59.3% among men. Cerebrovascular disease (mainly stroke) caused 15,409 deaths - 9,038 (8.5% of all deaths) among women and 6,371 (5.6% of all deaths) among men.
The total number of deaths from cardiovascular diseases was almost identical for men and women. More men died from ischemic heart disease and acute myocardial infarction, however, more women died from cerebrovascular disease and congestive heart failure.
|
Table 4-2 Numbers and Percent of Deaths Due to Cardiovascular Diseases by Age and Sex, Canada, 1999 |
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|
Age |
All Deaths |
All CVD1 |
IHD2 |
CBVD3 |
AMI4 |
CHF5 |
|||||
|
|
|
Number |
Percent of All Deaths |
Number |
Percent of All Deaths |
Number |
Percent of All Deaths |
Number |
Percent of All Deaths |
Number |
Percent of All Deaths |
|
Women |
|
|
|
|
|
|
|
|
|
|
|
|
<30 |
2,225 |
111 |
5.0 |
7 |
0.3 |
24 |
1.1 |
5 |
0.2 |
3 |
0.1 |
|
30-39 |
1,524 |
147 |
9.6 |
39 |
2.6 |
42 |
2.8 |
20 |
1.3 |
0 |
0.0 |
|
40-49 |
3,501 |
478 |
13.7 |
176 |
5.0 |
143 |
4.1 |
96 |
2.7 |
8 |
0.2 |
|
50-59 |
6,309 |
1,121 |
17.8 |
553 |
8.8 |
253 |
4.0 |
324 |
5.1 |
17 |
0.3 |
|
60-69 |
11,575 |
2,900 |
25.1 |
1,567 |
13.5 |
530 |
4.6 |
884 |
7.6 |
74 |
0.6 |
|
70-79 |
25,380 |
8,862 |
34.9 |
4,621 |
18.2 |
1,845 |
7.3 |
2,540 |
10.0 |
393 |
1.5 |
|
80-89 |
35,729 |
16,067 |
45.0 |
7,759 |
21.7 |
4,043 |
11.3 |
3,631 |
10.2 |
1,119 |
3.1 |
|
90+ |
19,618 |
9,448 |
48.2 |
4,280 |
21.8 |
2,158 |
11.0 |
1,478 |
7.5 |
1,032 |
5.3 |
|
All Ages |
105,861 |
39,134 |
37.0 |
19,002 |
17.9 |
9,038 |
8.5 |
8,978 |
8.5 |
2,646 |
2.5 |
|
Men |
|
|
|
|
|
|
|
|
|
|
|
|
<30 |
4,231 |
148 |
3.5 |
18 |
0.4 |
20 |
0.5 |
8 |
0.2 |
6 |
0.1 |
|
30-39 |
3,054 |
294 |
9.6 |
150 |
4.9 |
37 |
1.2 |
80 |
2.6 |
1 |
0.0 |
|
40-49 |
5,775 |
1,330 |
23.0 |
868 |
15.0 |
146 |
2.5 |
492 |
8.5 |
18 |
0.3 |
|
50-59 |
9,972 |
3,094 |
31.0 |
2,176 |
21.8 |
287 |
2.9 |
1,238 |
12.4 |
34 |
0.3 |
|
60-69 |
19,140 |
6,388 |
33.4 |
4,221 |
22.1 |
753 |
3.9 |
2,377 |
12.4 |
138 |
0.7 |
|
70-79 |
33,745 |
12,636 |
37.4 |
7,579 |
22.5 |
1,993 |
5.9 |
3,944 |
11.7 |
485 |
1.4 |
|
80-89 |
29,596 |
12,355 |
41.7 |
6,810 |
23.0 |
2,428 |
8.2 |
3,148 |
10.6 |
787 |
2.7 |
|
90+ |
8,155 |
3,563 |
43.7 |
1,795 |
22.0 |
707 |
8.7 |
661 |
8.1 |
376 |
4.6 |
|
All Ages |
113,668 |
39,808 |
35.0 |
23,617 |
20.8 |
6,371 |
5.6 |
11,948 |
10.5 |
1,845 |
1.6 |
|
Table does not include deaths with a missing age. 1 All CVD = All cardiovascular diseases (ICD code 9th revision 390-459) 2 IHD = Ischemic heart disease (ICD code 9th revision 410-414) 3 CBVD = (ICD code 9th revision 430-438) 4 AMI = Acute myocardial infarction (heart attack); (ICD code 9th revision 410), AMI is a sub-category of IHD 5. CHF = Congestive heart failure (ICD code 9th revision 428) Source: Health Canada; Statistics Canada, 2002 |
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Mortality Trends
Between 1969 and 1999, mortality rates for all cardiovascular diseases decreased by 56% (Figure 4-6). Rates for ischemic heart disease and cerebrovascular disease decreased by 62%, and for acute myocardial infarction by 70%. In comparison, between 1979 and 1999 the mortality rate due to congestive heart failure decreased by only 14%.
Among women, since 1969 mortality rates due to cardiovascular diseases decreased by 58% and by 64% due to ischemic heart disease, 62% due to cerebrovascular disease, and by 68% due to acute myocardial infarction (Figure 4-7). Rates for congestive heart failure decreased by 12%.
Mortality rates for cardiovascular diseases among men showed a decrease of 55% between 1969 and 1999 (Figure 4-8). Ischemic heart disease mortality rates decreased by 61%; rates for cerebrovascular disease decreased by 59%, and the decrease in rate for acute myocardial infarction was 71%. Between 1979 and 1999, mortality among men due to congestive heart failure decreased by 16%.
In 1999, 39,808 and 39,134 women died from cardiovascular diseases. Although mortality rates for all cardiovascular diseases have been declining during the 1990s, the actual number of deaths has remained steady at approximately 40,000 among men since the early 1990s, and at approximately 39,000 among women since the mid-1990s. This reflects the increase in the size of the population over the age of 65 years during this time period.
Based on Statistics Canada population projections and current trends in age-specific mortality rates, projections to 2025 suggest that, while the number of cardiovascular disease deaths for men will not increase, the number for women will increase until 2015 and then decrease (Figure 4-9). The number of deaths among women will likely surpass deaths among men in the near future, since women tend to live longer than men and the cardiovascular disease mortality rate increases with age.
The number of deaths due to ischemic heart disease among men is projected to continue on its downward trend (Figure 4-10). Among women, the numbers are projected to plateau and then decrease after 2010.
Figure 4 - 10
The number of deaths from acute myocardial infarction appears to be on a continuous downward trend for both men and women (Figure 4-11). After 2015, deaths among men are projected to fall below deaths among women.
Figure 4 - 11
Deaths due to congestive heart failure among both men and women increased between 1985 and 1995 (Figure 4-12). Since then, the number of deaths has been constant. The numbers are projected to increase for both men and women, however, due to increasing numbers in the elderly population.
Figure 4 - 12
The number of deaths from cerebrovascular disease is expected to increase among women until 2015, and then plateau (Figure 4-13). Among men, deaths are projected to increase through to 2025.
Figure 4 - 13
Age‑ and Sex‑Specific Death Rates
In 1999, mortality rates for cardiovascular diseases increased rapidly after age 65 and are higher for men than women at all ages (Figures 4-14).
Figure 4 - 14
Mortality rates for ischemic heart disease increased with age (Figure 4-15). While the rates among men were higher than among women for all ages, the male:female ratio decreased steadily with age: from 5:1 in the 40-49 year age group, to 4:1 in the 50-59 year age group, 3:1 among those aged 60-69 years, 2:1 in the 70-79 year age group, 1.6:1 in the 80-89 year age group and 1.2:1 among those aged 90+ years.
Figure 4 - 15
While mortality rates for acute myocardial infarction were lower than for ischemic heart disease, they showed very similar patterns by age group and sex (Figure 4-16).
Figure 4 - 16
In 1999, mortality rates due to congestive heart failure were very low among individuals under the age of 80 years (Figure 4-17). Over the age of 80 years, rates among men and women were very similar.
Figure 4 - 17
In 1999, men and women under the age of 60 years had very similar mortality rates for cerebrovascular disease (Figure 4-18). Men had slightly higher death rates between the ages of 60 and 89 years, after which the rate among women was higher than among men.
Figure 4 - 18
Potential Years of Life Lost
Calculating potential years of life lost (PYLL) provides an indication of the impact of premature death on society. PYLL is calculated as the sum of the number of years of life that individual Canadians “lost” - that is, did not live - due to premature death (considered, arbitrarily, as death prior to age 75 years).
In 1999, PYLL from cardiovascular diseases was responsible for an estimated 277,100 years and exceeded only by injuries and cancer, respectively (Figure 4-19).
Figure 4 - 19
Regional Comparisons
The average cardiovascular disease mortality rates during 1995-1999 were much higher for men and women in Newfoundland than in all other provinces or territories (Figure 4-20). Rates in B.C., the Northwest Territories and Nunavut were at the lower end (provincial/territorial cardiovascular disease rates have been age-adjusted).
Figure 4 - 20
Mortality rates due to ischemic heart disease among men followed a generally upward west-east gradient with the exception of New Brunswick, where rates for men were lower than in Manitoba, Ontario and Quebec (Figure 4-21). No clear pattern was seen among women.
Figure 4 - 21
Quebec and Newfoundland had higher
mortality rates than the rest of the provinces and territories due to acute
myocardial infarction, while Alberta, Nunavut, Northwest Territories and the
Yukon had lower rates
(Figure 4-22).
Figure 4 - 22
The highest mortality rate among women due to congestive heart failure during 1995-1999 was found in Nunavut. It was 3 times higher than in any other province or territory, and higher than the rate for men in any of the provinces or territories (Figure 4-23). The rate for men in the Northwest Territories was also very high compared to other provinces and territories. Lower rates were found in the Yukon, Alberta and Ontario.
Figure 4 - 23
Between 1995 and 1999, Nunavut reported the lowest rate of mortality from cerebrovascular disease in Canada for both men and women (Figure 4-24). For men, Newfoundland reported the highest rates, followed by P.E.I. and Manitoba, while Quebec and Nova Scotia reported the lowest. In the Yukon, rates among women were higher than among men.
Figure 4 - 24
International Comparisons
In the 1990s, cardiovascular diseases were the leading cause of death worldwide, but rates varied considerably among countries (international cardiovascular disease rates have been age-adjusted). Among the 20 countries with the lowest mortality rates as reported to WHO, Canada ranked 4th for cardiovascular disease mortality among men and 3rd among women (Figure 4-25). While these international rates provide an overview of the worldwide situation, they were derived from the different countries in different years, using different methods, depending on when statistics were collated. Caution must be used, therefore, in making comparisons between countries.
Figure 4 - 25
Overall, Canada ranks 14th lowest in mortality from ischemic heart disease among men and women (Figure 4-26). France has the lowest mortality rate (approximately 50% less than Canada). While the mortality rates from ischemic heart disease have been declining in Canada and other Western countries during the past decade, they have been increasing in the Russian Federation and in a number of countries in the developing world.
Figure 4 - 26
For cerebrovascular disease, Canada ranked 2nd lowest for men (behind Switzerland) and 3rd lowest for women behind Switzerland and France (Figure 4-27)
Figure 4 - 27
Although differences in risk factors and quality of treatment may account for international differences in mortality rates, much of the difference remains unexplained. The expectation is that, given the change to a western diet and increase in smoking rates, the rate of cardiovascular diseases in less-developed countries will rise in the future and become a major burden to their respective populations.
Discussion
The data regarding mortality and quality of life show the tremendous burden of cardiovascular diseases in Canada.
Cardiovascular diseases are the underlying cause of death for 1 in 3 Canadians. The number of deaths, and by proxy the number of Canadians with cardiovascular diseases, will likely increase as the population ages. Thus, the burden of cardiovascular diseases will continue for many more years.
The mortality figures provide only part of the picture, however. Overall, 5.7% of Canadian adults, and nearly 1 in 4 aged 70+ years, report having heart problems and they, with their families, know personally the challenges of living with cardiovascular diseases. They feel less healthy than the rest of the Canadian population, many must restrict their activities, and many need help with the normal activities of daily living. While the 70+ age group has the highest rates of cardiovascular diseases, many Canadians develop the condition in their forties and fifties.
In comparison to other countries, Canada has one of the lowest mortality rates due to stroke. In contrast, Canada does not appear to fare as well when comparing its ischemic heart disease mortality rate to other countries (international cardiovascular disease rates have been age-adjusted). Canada may be able to learn successful approaches to reducing both the incidence and premature death rate due to ischemic heart disease from other countries.
Within Canada, cardiovascular disease rates vary among the provinces/territories (provincial/territorial cardiovascular disease rates have been age-adjusted). Newfoundland has consistently higher mortality rates than the other provinces/territories for cardiovascular diseases overall, and for ischemic heart disease, acute myocardial infarction and cerebrovascular disease. Newfoundlanders also reported a higher prevalence of all modifiable risk factors than the Canadian population overall (Chapter 1). With the exception of congestive heart failure, mortality rates from cardiovascular diseases were lower in the north than in Canada as a whole.
Mortality rates for both men and women for ischemic heart disease, acute myocardial infarction and cerebrovascular disease continue to decrease. The rate for congestive heart failure is decreasing as well, but at a slower pace. This may be a result of both the rising incidence of the disease and a possible shift in diagnostic labelling from ischemic heart disease.
Even though cardiovascular disease mortality rates have decreased, in the future the number of women who will die from cardiovascular diseases is expected to increase due to the aging population. As a result, the burden of cardiovascular diseases in the population will increase.
Cardiovascular diseases affect men and women differently. More men than women die from ischemic heart disease and acute myocardial infarction but more women than men die from congestive heart failure and cerebrovascular disease.
One of the gaps in our knowledge of health outcomes is the lack of data on the incidence and prevalence of cardiovascular diseases and the lack of more detailed data on its impact on quality of life and on outcomes of treatment.
Implications for Action
· Increase home care, pharmacare and palliative care services to cope with the projected increase in the number of people who will be dying from cardiovascular diseases in the future.
· Explore reasons behind the higher ischemic disease mortality rates in Canada compared to other countries.
· Develop an ongoing system of data collection to monitor the incidence and prevalence of cardiovascular diseases, their impact, and treatment outcomes.