This article provides a brief overview of the differentials in prevalence, risk factors, hospitalisations and trends in morbidity for cardiovascular disease in Australia using data from the 2001 ABS National Health Survey. The article also draws on data from the ABS Causes of Death collection.
For further information about these and related statistics, contact the National Information and Referral Service on 1300 135 070 or Jane Griffin-Warwicke on Canberra (02) 6252 6535.
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).
DISEASES OF THE CIRCULATORY SYSTEM ARE CLASSIFIED AS:
An underlying contributor to cardiovascular disease is atherosclerosis, a process that forms abnormal build-up of fat, cholesterol and other substances in the inner lining of the arteries (plaque). This process leading to atherosclerosis is slow and complex, often starting at childhood and it progresses with age. When blood supply to the heart is affected, it can result in angina, a heart attack or sudden death. Conversely, a stroke may be caused as a result of insufficient supply of blood to the brain (AIHW 2004).
Unless otherwise stated this article presents information sourced from the 1989-90 and 2001 ABS National Health Survey (NHS).
- Acute rheumatic fever (100-102);
- Chronic rheumatic heart disease (105-109);
- Hypertensive disease (110-115);
- Ischaemic heart disease (120-125);
- Pulmonary heart disease and diseases of pulmonary circulation (126-128);
- Other forms of heart disease (130-152);
- Cerebrovascular disease (160-169);
- Diseases of arteries, arterioles and capillaries (170-179);
- Disease of veins, lymphatic vessels and lymph nodes, not elsewhere classified (180-189); and
- Other and unspecified disorders of the circulatory system (195-199).
- In 2001, 17% (3.2 million) of people reported having cardiovascular disease as a long-term condition.
- The difference between the overall prevalence of cardiovascular disease for females (18.8%) and males (14.8%), was not statistically significant.
- However, women were more likely than men to report having oedema and varicose veins and men were more likely than women to report other ischaemic heart disease and diseases of arteries, arterioles and capillaries.
- The prevalence rate of cardiovascular disease increased with age, peaking at 40% for people aged 65 years and over.
- After adjusting for age differences, 19% of Indigenous Australians reported having long-term cardiovascular conditions compared with 17% of non-Indigenous Australians.
- Of Indigenous Australians aged 35-44 years, 16% reported a cardiovascular condition. The rate increased to 31% for those aged 45 to 54 years, and to 47% for those aged 55 years and over.
Persons reporting cardiovascular disease(a), 2001
LOWER SOCIOECONOMIC GROUPS
- The most commonly reported condition of the circulatory system was hypertension.
- The prevalence of hypertension increased rapidly from age 35 years, with the onset approximately 10 years younger for the non-Indigenous population.
- In Australia, people in lower socioeconomic groups are at greater risk of cardiovascular disease and related mortality (AIHW 2004).
- In 2001, after adjusting for age differences, those 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 (20% compared with 17%).
- The death rates for such groups are double that of people living in less socioeconomically disadvantaged areas. In 1997, in the 25-64 age group, the number of deaths from cardiovascular disease in those living in the most disadvantaged areas was twice the rate of those living in the least disadvantaged areas (AIHW 2001).
- In 2001, rates of prevalence were highest among those who were born in Southern-Eastern Europe (29.9%), North-West Europe (23.7%) and United Kingdom (23.7%) than those born in Australia (15.9%), North Africa and Middle East (13.6%) and South East Asia (13.0%).
- Major preventable risk factors for cardiovascular disease are tobacco smoking, high blood pressure, high blood cholesterol, insufficient 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).
- Since 1989-90, the proportion of adults who were current smokers has declined (down from 28% to 24% in 2001).
- After adjusting for age differences, a similar proportion of adults (aged 18 years and over) with and without cardiovascular disease reported being a current daily smoker (24% and 25% respectively). Those with cardiovascular disease were slightly more likely to be ex-smokers than those without cardiovascular disease (28% compared with 26%).
OVERWEIGHT AND OBESITY
- Physical inactivity is recognised as having a causal role in heart disease and stroke (AIHW 2004).
- The proportion of people exercising at a moderate to high level showed little change between 1989-90 to 2001 (remaining around 30% over the period).
- After adjusting for age differences, those aged 15 years and over with cardiovascular disease were more likely to report having little or no exercise in the last two weeks prior to the survey (73%) than those without cardiovascular disease (67%). They were also less likely to report having high (5% compared with 7%) or moderate (22% compared with 25%) level of exercise.
- Overweight and obesity are associated with diseases and conditions such as coronary heart disease, heart failure, stroke, high blood pressure, high blood cholesterol, Type 2 diabetes, certain cancers and psychosocial problems (AIHW 2004).
- In 2001, 30% of persons aged over 15 years were classified as being overweight and 14% were obese according to their reported body mass index (BMI). Males were more likely to be overweight (38% compared with 22% females), however the proportion of obese persons was similar for both males and females (14% and 15% respectively).
- There has been an increase in the proportion of overweight and obese Australians. In 1989-90, 36% of persons aged 15 years and over were overweight or obese, which increased to 39% in 1995 and 44% in 2001.
- After adjusting for age differences, people with cardiovascular disease aged 15 years and over were more likely to be obese than those people without cardiovascular problems (21% compared with 12%). A similar proportion of people with and without cardiovascular disease were in the overweight range (29% and 30% respectively).
- The effect of nutrition on the risk of cardiovascular disease results from the combined effects of individual dietary factors and total energy intake if it leads to overweight and obesity and cannot be attributed to any one dietary component alone (AIHW 2004).
- Dietary risk factors for cardiovascular disease include high intake of fat, dietary cholesterol, salt and low consumption of fruit and vegetables (AIHW 2001).
- In 2001, after adjusting for age differences, people aged 15 years and over with cardiovascular disease were more likely to report that they usually consumed low/reduced fat milk (32% compared with 30%) and skim milk (15% compared with 12%) than people without the disease. They were less likely to report having whole milk (43% compared with 49% ).
- After adjusting for age differences, a similar proportion of people with cardiovascular disease (aged 15 years and over) reported usually eating 2-3 serves of fruit a day to those without the disease (41% compared with 42%).
- Those with cardiovascular disease aged 15 years and over (after age standardisation) were more likely to have reported having 4-5 serves of vegetables a day (27% compared with 25%) and less likely to have 1 serve or less (19% compared with 22%) than people without cardiovascular disease.
- People with diabetes are at an increased risk of developing coronary heart disease, stroke and peripheral vascular disease (AIHW 2004).
- Diabetes is both a risk factor for cardiovascular disease and a condition in its own right. In 2001, 2.9% of the Australian population reported they had diabetes.
- In 2001, over half the people who reported having cardiovascular disease (54%) also reported having diabetes.
- In 1998-99 cardiovascular disease was the principal diagnosis for 437,717 hospitalisations in Australia (7% of all hospitalisations). More than a third (36%) of hospitalisations were attributable to coronary heart disease, 12% to stroke and 10% to heart failure (AIHW 2001).
- The average length of stay in hospital for cardiovascular disease has declined from 7.6 days in 1993-94 to 5.5 days in 1998-99. The number of same-day patients has increased, particularly for coronary heart disease (67%) (AIHW 2001).
- The use of calcium channel blockers (which reduces blood pressure and angina) have risen over the last decade (AIHW 2004).
- Angiotensin-converting enzymes (ACE) inhibitors and angiotensin receptor antagonists have become the most frequently used class of blood pressure lowering drug (AIHW 2004).
- Statins are a type of lipid-lowering drug and their use has increased since 1994, doubling between 1998-2000 (AIHW 2004).
- The use of antiplatelet drugs like aspirin has risen markedly since the late 1990s (AIHW 2004).
- In 2000, the cost of heart, stroke and vascular drugs sold under the PBS amounted to 34% of the government and patient costs for all prescription PBS drugs dispensed through pharmacies (AIHW 2004).
- Over 51 million prescriptions for heart, stroke and vascular drugs were dispensed in 2000; which is one-quarter of all prescriptions (AIHW 2004).
TRENDS IN MORBIDITY
- Cardiovascular disease continues to generate a considerable burden on the Australian population in terms of illness and disability. The issue of morbidity will become more acute in the future as the number of older Australians increases, among whom cardiovascular disease is more common (AIHW 2004).
- Cardiovascular disease is a leading cause of disability in Australia. In 1995, the rate of morbidity and disability from this disease was 2.8 per 1,000 population (AIHW: de Looper 2001).
- Cardiovascular morbidity directly affects one in three Australian families. In 1993-94 it accounted for the major proportion of total recurrent health expenditure (12% or $3.9 billion) (AIHW: de Looper 2001).
- 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).
- In 1998, of all cardiovascular conditions, strokes were the principal cause of serious long-term disability in adults in Australia. The 1998 Survey of Disability, Ageing and Carers estimated that there were 63,530 Australians with a disability caused mainly by stroke (ABS 1998).
- Despite declines in mortality rates in the past thirty years, cardiovascular disease (or diseases of the circulatory system) remains one of the leading causes of death in Australia in 2002, accounting for 50,294 or 38% of all deaths (ABS 2002). Cardiovascular disease is also one of the largest causes of premature death in Australia (AIHW & DHAC 1999).
Deaths from Cardiovascular disease(a), Age Standardised Rates(b) - 1992-2002
- The two cardiovascular diseases causing the highest number of deaths were ischaemic heart disease and cerebrovascular disease (stroke). In 2002, ischaemic heart disease accounted for 20% of all deaths of males, and 19% of all deaths of females. Stroke has been the second most common cause of cardiovascular death since 1968, causing 7% of all deaths of males and 12% of all deaths of females in 2002.
- In terms of hospitalisation, the Australian Institute of Health and Welfare (AIHW) reported that those hospitalised for stroke have the highest in-hospital mortality (10.7% of stroke hospitalisations). Heart failure (8.9%) had the next highest rate, followed by peripheral vascular disease (8.2%), coronary heart disease (2.9%) and rheumatic fever and rheumatic heart disease (2.4%) (AIHW 2001).
Australian Bureau of Statistics 2002, Causes of Death Australia, cat. no. 3303.0. ABS, Canberra.
Australian Bureau of Statistics 2001, National Health Survey: Summary of Results, Australia, 2001, cat. no.4364.0, ABS, Canberra.
Australian Bureau of Statistics 2001, National Health Survey: Aboriginal and Torres Strait Islander Results, Australia, 2001, cat. no. 4715.0, ABS, Canberra.
Australian Bureau of Statistics 1998, Disability, Ageing and Carers, cat. no. 4430.0, ABS, Canberra.
Australian Institute of Health and Welfare 2001, Heart, Stroke and Vascular Disease - Australian facts 2001. AIHW Cat. No. CVD 13, Canberra: AIHW, National Heart Foundation of Australia (Cardiovascular Disease Series No.14).
Australian Institute of Health and Welfare 2004, Heart, Stroke and Vascular Disease - Australian facts 2004. AIHW Cat. No. CVD 27, Canberra: AIHW, 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.
Australian Institute of Health and Welfare 1999, National Health Priority Areas Report, Cardiovascular health: a report on heart, stroke and vascular disease. AIHW Cat. No. PHE 9, Commonwealth Department of Health and Aged Care.