This article provides a brief overview of the prevalence, risk factors, hospitalisations and trends in morbidity for cardiovascular disease in Australia principally using data drawn from the National Health Survey (NHS). Some data are also provided on specific cardiovascular conditions and a subset of cardiovascular conditions referred to in this article as heart, stroke and vascular conditions.
Information for this article is drawn from the ABS 2001 and 2004-05 National Health Surveys, the 2004-05 National Aboriginal and Torres Strait Islander Health Survey, 2004 Causes of Death collection and the 2003 Survey of Disability, Ageing and Carers.
Cardiovascular conditions were recorded in the NHS if the respondent reported that they had been told by either a doctor or nurse that they had the condition. The 2001 and 2004-05 NHS collected data from persons living in private dwellings in rural and urban areas, and excluded persons living in remote areas and in non private accommodation such as hospitals, nursing and convalescent homes, hotels, motels and short stay caravan parks.
For further information about these and related statistics, contact the National Information and Referral Service on 1300 135 070 or email <firstname.lastname@example.org>.
Despite steady improvement over the last three decades, cardiovascular disease remains one of the biggest causes of death in Australia and continues to generate a considerable burden on the population in terms of illness and disability. In relation to direct health care expenditure, cardiovascular disease is the most expensive health condition, costing 11% or 5.4 billion dollars of the total allocated health system expenditure in 2000-01 (AIHW 2005a). The incidence of cardiovascular disease increases with age and the number of people with cardiovascular disease may increase in the future as the number of older Australians increases (AIHW 2004).
TYPES OF CARDIOVASCULAR DISEASE
Cardiovascular disease, or diseases of the circulatory system, includes all diseases of the heart and blood vessels. Diseases of the circulatory system are classified according to the International Classification of Diseases (ICD-10) and are classified as:
An underlying contributor to cardiovascular disease is atherosclerosis, a process involving abnormal build-up of fat, cholesterol and other substances (plaque) in the inner lining of the arteries. This development of atherosclerosis is slow and complex, usually starting in childhood and progressing with age. When blood supply to the heart is affected, it can result in angina, a heart attack or sudden death. When an artery supplying blood to the brain suddenly becomes blocked or bleeds, this may result in a stroke causing paralysis, speech and other problems (AIHW 2004).
A subset of cardiovascular conditions referred to in this article as heart, stroke and vascular conditions includes:
- Acute rheumatic fever (I00-I02);
- Chronic rheumatic heart disease (I05-I09);
- Hypertensive disease (I10-I15);
- Ischaemic heart disease (I20-I25);
- Pulmonary heart disease and diseases of pulmonary circulation (I26-I28);
- Other forms of heart disease (I30-I52);
- Cerebrovascular disease (I60-I69);
- Diseases of arteries, arterioles and capillaries (I70-I79);
- Disease of veins, lymphatic vessels and lymph nodes, not elsewhere classified (I80-I89); and
- Other unspecified disorders of the circulatory system (I95-I99).
- Other ischaemic heart disease
- Cerebrovascular diseases
- Oedema and heart failure
- Diseases of arteries, arterioles and capillaries
- In 2004-05, 18% (approximately 3.5 million) of Australians reported having a long-term cardiovascular condition.
- The most common cardiovascular condition was hypertension (high blood pressure), reported by 11% (2.1 million).
- The proportion reporting heart, stroke or vascular conditions was 3.8% of the Australian population.
- Of those reporting heart, stroke and vascular conditions, 28% reported having angina, 20% an other ischaemic heart disease, 12% a cerebrovascular disease, 35% oedema and heart failure and 27% reported having a disease of the arteries, arterioles and capillaries (footnote 1).
- The number of Australians with heart, stroke or vascular conditions decreased from 4.3% of the population in 2001, to 3.8% in 2004-05 (age adjusted) (footnote 2).
Prevalence of heart, stroke and vascular conditions, 2004-05
Source ABS, National Health Survey: Summary of Results, Australia, 2004-05 cat. no 4364.0
AGE AND SEX
- The prevalence of cardiovascular disease increases with age. In 2004-05, of those aged 35 to 44 years, 13% reported a long term cardiovascular condition. This increased to 23% for those aged 45 to 54 years and 63% for those aged 75 years and over.
- The proportion of females reporting cardiovascular disease was higher than for males in every age group except 75 years and over.
- Overall, 20% of females reported having a cardiovascular disease compared to 16% for males.
- The proportion of males and females who reported having heart, stroke and vascular diseases was similar (51% and 49% respectively).
- Of reported heart, stroke and vascular diseases females were more likely than males to report oedema and heart failure (23% compared to 11%).
- Males were more likely than females to have angina and other ischaemic heart diseases (30% compared to 18%) and diseases of the arteries, arterioles and capillaries (17% compared to 10%).
Reported prevalence of cardiovascular conditions, 2004-05
Age group (years)
Source ABS, National Health Survey: Summary of Results, Australia, 2004-05 cat. no 4364.0
- In 2004–05, 12% of Indigenous Australians reported having a cardiovascular condition.
- The most commonly reported cardiovascular condition among Indigenous Australians was hypertension which affected 22% of those aged 35 years and over.
- One in five Indigenous Australians aged 35–44 years (21%) reported a cardiovascular condition. The proportion increased to 31% for those aged 45–54 years, and to 54% for those aged 55 years and over.
- The prevalence of cardiovascular conditions increased rapidly for Indigenous people from around 35 years of age onwards, some 10 years earlier than in the non-Indigenous population.
- After adjusting for age differences between the two populations, Indigenous Australians were 1.3 times more likely than non-Indigenous Australians to report cardiovascular condition in 2004–05.
Reported prevalence of cardiovascular conditions, 2004-05
Source: ABS, National Aboriginal and Torres Strait Islander Health Survey, 2004-05, cat. no. 4715.0
COUNTRY OF BIRTH
- In 2004-05, the prevalence of cardiovascular disease was highest amongst those who were born in North-West Europe (29%) followed by the United Kingdom and Southern Eastern Europe (both at 28%), North Africa and the Middle East (19%), Australia (17%) and South East Asia (15%).
- In Australia, people in lower socioeconomic groups are at greater risk of cardiovascular disease and related mortality (AIHW 2006b).
- In 2004-05, people with cardiovascular disease were more likely to live in the most disadvantaged socioeconomic areas (those in the lowest SEIFA quintile) than those without cardiovascular diseases (22% compared with 17%) (footnote 3).
- Similarly for those with heart, stroke and vascular disease, 5.2% of those in the most disadvantaged areas reported a heart, stroke and vascular disease compared to those in the least disadvantaged areas (2.7%).
- The death rates for people suffering from cardiovascular disease are also affected by socioeconomic disadvantage with death rates around 20% higher for those living in disadvantaged areas (AIHW 2004).
- People who had cardiovascular disease reported their overall health as being lower than those without a cardiovascular disease. Of those with cardiovascular disease 33% reported their own health as being poor/fair. Of those without cardiovascular disease only 11% rated their own health as poor/fair, while 62% reported their health to be very good/excellent.
- Of those who had a cardiovascular disease, 12% also had diabetes, 39% also had arthritis and 14% also had a mental and behavioural health problem.
- For those who had both a cardiovascular disease and diabetes 57% reported that their own health was poor/fair while only 14% reported their health as very good/excellent. There was also a larger difference reported by those with both a cardiovascular disease and arthritis (46% and 24% respectively) and for those with both a cardiovascular disease and a mental and behavioural problem (52% and 22%).
- Major preventable risk factors for cardiovascular disease include tobacco smoking, hypertensive disease (high blood pressure), high blood cholesterol, inadequate physical activity, overweight and obesity, poor nutrition and diabetes (AIHW 2004).
- Tobacco smoking increases the risk of coronary heart disease, stroke, and peripheral vascular disease as well as a range of cancers and other diseases and conditions (AIHW 2004).
- The proportion of adults who are current smokers has changed marginally over time dropping from 24% in 2001 to 23% in 2004-05 (age adjusted).
- Older people, aged 75 years and over, the age group most likely to have a cardiovascular disease, are less likely to be current smokers (4% in 2005) than people in the younger age groups (10% of those aged 65-74 years, and 26% of those aged 18-64 years were current smokers in 2005).
- Of those adults reporting having a cardiovascular disease 15% also reported being a current daily smoker. This compares to 23% for those without cardiovascular disease. Those with a cardiovascular disease were also more likely to be ex-smokers than those without cardiovascular disease (39% compared with 27%).
Hypertension (high blood pressure)
High blood cholesterol
- Hypertension is a risk factor for other cardiovascular diseases as well as a common cardiovascular condition (footnote 4).
- Data from the 2004-05 NHS showed that prevalence rates for hypertensive disease increased with age with 14% of those aged 45-54 years reporting the disease compared to 41% for those aged 75 years and over.
- Every year 3% of the adult population develop hypertensive disease with the risk increasing from 1% for those aged between 25 and 34 years to 8% for those aged between 65 and 74 years (IDI 2006).
- In 2004-05, 7% of the population reported having been told by a doctor or nurse that they have high blood cholesterol. The rate for those aged over 65 years was higher at 22% (footnote 5).
- Of Australians reporting a cardiovascular condition, 40% also reported having high blood cholesterol.
Overweight and obesity
- Despite the publicised importance of physical activity there have been no increases in the level of physical exercise reported by Australians in recent National Health Surveys.
- Data from the 2001 and 2004-05 surveys (age adjusted) has shown that the proportion of adults exercising at a sedentary to low level has remained steady at around 70% of the population.
- Those aged 15 years and over with cardiovascular disease were slightly more likely to report having little or no exercise in the two weeks prior to the survey (74%) compared to those without cardiovascular disease (68%).
- Overweight and obesity are associated with diseases and conditions such as coronary heart disease, heart failure, stroke, high blood pressure and high blood cholesterol (AIHW 2004).
- In 2004-05, 34% of persons aged 15 and over years were classified as being overweight, and 17% were obese, according to their reported height and weight (footnote 6).
- The proportion of overweight and obese Australians is increasing. In 1995, 39% of persons aged 15 years and over were classified as overweight or obese. This increased to 44% in 2001 and 47% in 2004-05 (age adjusted).
- People aged 15 years and over with cardiovascular disease were more likely to be classified as overweight or obese than those people without cardiovascular disease (63% compared with 48%).
- Australians reporting heart, stroke and vascular diseases aged 15 years and over were much more likely to be classified as overweight or obese than those without heart stroke and vascular disease (65% compared with 51%).
- People with diabetes are at an increased risk of developing coronary heart disease, stroke and peripheral vascular disease (AIHW 2004).
- In 2004-05, 60% of people reporting diabetes also reported having a cardiovascular disease.
- The use of calcium channel blockers (which reduces blood pressure and angina) have risen over the last decade (AIHW 2004). In 2004-05, 21% of those reporting the use of a medication for a circulatory condition in the previous two weeks reported using Calcium channel blockers.
- Angiotensin-converting enzymes (ACE) inhibitors and angiotensin receptor antagonists have become the most frequently used class of blood pressure lowering drug (AIHW 2004).
- Of those reporting the use of a medication for a circulatory condition in the previous two weeks prior to being interviewed in 2004-05, the most commonly reported were ACE inhibitors (34%) followed by Angiotensin II antagonists (27%).
- Disabilities and core activity restrictions can be long-term consequences of cardiovascular conditions, particularly stroke, and can have a severe impact on the quality of life of the sufferer (AIHW: de Looper 2001) (footnote 7).
- The 2003 Survey of Disability, Ageing and Carers estimated that of all those Australians who had a disability, 69,800 or 1.8 % were caused mainly by stroke (ABS 2004b).
- In 2003-04, cardiovascular disease was the principal diagnosis for 7% or 448,859 hospitalisations in Australia. Of these, more than a third (37%) were attributable to coronary heart disease, 14% to heart rhythm disorders, 9% to heart failure, 7% to stroke and 6% to peripheral vascular disease (AIHW 2006a).
- In 2003-04, the average stay for those staying at least one night was six days with the length of stay for stroke and peripheral heart disease being at least twice as long as that for coronary heart disease (AIHW 2006a).
1. Because persons have reported having more than one type of heart, stroke and vascular condition the total percentage of persons reporting to have a heart, stroke and vascular condition will add up to more than one hundred. Back
2. Since many health characteristics are age-related, the age profile of the populations being compared needs to be considered when interpreting the data. To account for the differences in age structure, the data comparing characteristics over time in this article are shown as age standardised percentages. For further detail, see the Explanatory Notes of the 2004-05 National Aboriginal and Torres Strait Islander Health Survey: Users' Guide - Electronic Publication, Australia (4715.0.55.004). Back
3. This is one of four Socio Economic Indexes for Areas (SEIFAs) compiled by ABS following each Census of Population and Housing. The indexes are compiled from various characteristics of persons resident in particular areas; the index of disadvantage summarises attributes such as low income, low educational attainment, high unemployment and jobs in relatively unskilled occupations. For further information about SEIFAs see Chapter 6 of the 2004-05 National Health Survey: Users' Guide. Back
4. Rates of self reported hypertension may not accurately reflect real levels. Data from the 1999-2000 Australian Diabetes, Obesity and Lifestyle (AusDiab) obtained using diagnosis show that one in three Australians aged over 24 years have high blood pressure (IDI 2006). Back
5. Rates of self reported high blood cholesterol may not accurately reflect actual levels as data from the 1999-200 AusDiab study suggest that levels of high blood cholesterol in the Australian population may be as high as 51% (AIHW 2005b). Back
6. Categories reported against are those set out by the World Health Organisation (WHO) and the National Health and Medical Research Council (NHMRC) guidelines. Those men (5%) and women (11%) who either declined or were unable to provide their height and /or weight are excluded from calculations. Obesity was derived from self reported height and weight. Studies have shown that people tend to under-estimate their weight and over-estimate their height. (ABS 1998). This means that the estimate for people that are obese is likely to be an under-estimate. Back
7. Core activities comprise communication, mobility and self care. Back
LIST OF REFERENCES
Australian Bureau of Statistics 2006a, National Health Survey: Summary of Results, Australia, 2004-05, cat. no.4364.0, ABS, Canberra.
Australian Bureau of Statistics 2004a, Causes of Death Australia, cat. no. 3303.0. ABS, Canberra.
Australian Bureau of Statistics 2004b, Disability, Ageing and Carers: Summary of Results, Australia, 2003, cat. no. 4359.0, ABS, Canberra.
Australian Bureau of Statistics 1998, How Australians Measure Up, Australia, 1998, cat. no.4364.0, ABS, Canberra.
Australian Institute of Health and Welfare 2006a, Australia's Health, 2006, AIHW Cat. No. AUS 73, AIHW, Canberra.
Australian Institute of Health and Welfare 2006b, Socioeconomic inequalities in cardiovascular disease in Australia, Bulletin no. 37, AIHW Cat. No. AUS 74, AIHW, Canberra.
Australian Institute of Health and Welfare 2005a, Health system expenditure on disease and injury in Australia, 2000-01. 2nd edition, AIHW Cat. No. HWE 26, AIHW, Canberra.
Australian Institute of Health and Welfare 2005b, Living dangerously: Australians with multiple risk factors for cardiovascular disease, Bulletin no. 24, AIHW Cat. No. AUS 57, AIHW, Canberra.
Australian Institute of Health and Welfare 2004, Heart, Stroke and Vascular Disease - Australian Facts 2004, AIHW Cat. No. CVD 27, AIHW, Canberra National Heart Foundation of Australia (Cardiovascular Disease Series No.22).
Australian Institute of Health and Welfare: de Looper, M & Bhatia, K 2001, Australian Health Trends 2001, AIHW Cat. No. PHE 24. Canberra: AIHW.
International Diabetes Institute 2006, Tracking the Accelerating Epidemic: Its Causes and Outcomes, The Australian Diabetes, Obesity and Lifestyle Study (AusDiab) 2006, Melbourne.
- Although mortality rates for cardiovascular disease (or diseases of the circulatory system) are continuing to fall, cardiovascular disease remains one of the leading causes of death in Australia, accounting for 47,637 or 36% of deaths in 2004 (ABS 2006a).
- Cardiovascular disease is also one of the largest causes of premature death in Australia (AIHW 2004).
- The two cardiovascular diseases causing the highest number of deaths were ischaemic heart disease and cerebrovascular disease. In 2004, ischaemic heart disease accounted for 19% of all deaths of males, and 18% of all deaths of females. Stroke has been the second most common cause of cardiovascular death since 1968, causing 7% of all deaths for males and 11% of all deaths for females in 2004 (ABS 2004a).