Risk factors
Contents
- Why are risk factors included in the National Health Priority Areas initiative?
- Focus National Health Priority Area risk factors?
Why are risk factors included in the National Health Priority Areas initiative?
A variety of risk factors contribute to the development and maintenance of NHPA diseases and conditions. The NHPA initiative recognises that strategies are needed to control these risk factors to prevent the onset and reduce the long-term impact of NHPA diseases and conditions. The surveillance and monitoring of these risk factors also provide some insights into the underlying trends for the burden of disease associated with various NHPA diseases and conditions.
Several risk factors are commonly shared by NHPA diseases and conditions. Major among these are physical inactivity, excess body weight, tobacco smoking, and poor diet and nutrition. Diabetes, coronary heart disease, stroke and colorectal cancer between them share the most risk factors, namely physical inactivity, excess weight and poor diet and nutrition. Risk factors such as high blood pressure and high blood cholesterol are specific to coronary heart disease and stroke.
| NHPA disease or condition |
Risk factor | |||||
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| Tobacco smoking | Physical inactivity | Poor diet & nutrition | Excess body weight | High blood pressure | High blood cholesterol | |
| Type 2 Diabetes |  |
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| Asthma | |
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| Coronary heart disease | |
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| Stroke | |
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| Lung cancer | |
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| Colorectal cancer | |
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| Osteoarthritis | |
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| Osteoporosis | |
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Focus National Health Priority Area risk factors?
The initial focus, under the NHPA initiative, is on lifestyle and behavioural risk factors such as tobacco smoking, physical activity, and diet and nutrition. Emphasis is also placed on monitoring excess body weight, high blood pressure and high blood cholesterol.
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Tobacco smoking
Tobacco smoking is a major contributor to mortality and ill-health of Australians. Of all the health risk factors, smoking is responsible for the greatest burden of disease in Australia, around 12% of the total burden of disease in males and 7% in females in 1996.
Cigarettes and other tobacco products contain carcinogens (cancer-causing agents), nicotine (an addictive agent) and numerous other poisonous substances. People who use tobacco have an increased risk of developing coronary heart disease, stroke, heart failure, peripheral vascular disease, lung cancer, cervical cancer and osteoporosis. These risks increase with the number of cigarettes smoked daily, with the number of years of smoking, and especially when the habit is started at an early age.
Tobacco smoke affects not only the individual user, but also others who may be exposed to it. Environmental tobacco smoke has been shown to be associated particularly with the exacerbation of childhood respiratory diseases such as asthma.
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Physical inactivity
Physical inactivity, defined as people undertaking 'insufficient' physical activity to achieve measurable health outcomes, is a strong risk factor for a range of NHPA diseases and conditions. It can also contribute to other risk factors such as increases in blood pressure, blood cholesterol levels and overweight and obesity.
There is strong evidence that a lack of regular physical activity is associated with an increased risk of mortality and morbidity from heart and vascular diseases, particularly coronary heart disease. There is also some association between physical inactivity and an increase in risk of some types of stroke, heart failure and peripheral vascular disease. Insufficient physical activity increases the risk of Type 2 diabetes, osteoarthritis, osteoporosis and some cancers; in particularly, an increased risk for post-menopausal breast cancer and colorectal cancer.
Physical activity has a beneficial effect on improving various aspects of health including cardiovascular disease, musculoskeletal health and diabetes. Physical activity may also assist in the reduction in symptoms of depression and reduce the risks of developing some cancers, such as prostate cancer.
Physical inactivity has been ranked second only to tobacco smoking, in terms of the burden of disease and injury from risk factors in Australia.
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Poor diet and nutrition
Diet and nutrition play a major role in health and disease. In recent decades much evidence has shown that dietary patterns can contribute to the risk of various diseases and their immediate risk factors.
Poor diets often result from over-consumption of food in general, or diets high in energy-rich components such as fat. A poor diet may also be low in dietary fibres or complex carbohydrates, and deficient in certain vitamins and minerals.
In developed nations, the problem is more closely associated with excess consumption rather than nutritional deficits that are experienced in developing nations.
Poor diet plays a key role in the development and progression of NHPA diseases such as coronary heart disease, stroke, Type 2 diabetes and some forms of cancer such as colorectal cancer and post-menopausal breast cancer. It may also increase the risk of prostate cancer, although this link is less clear. Poor diet and nutrition also contributes to a variety of other health risk factors such as high blood pressure, excess weight and high blood cholesterol.
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Excess body weight
Excess body weight, a term used to refer to both overweight and obesity, is a condition that occurs due to excess body fat resulting from an energy imbalance, where energy consumption (nutritional patterns) exceeds energy expenditure over a considerable period of time.
Excess body weight has been clearly linked with increased risk of mortality and morbidity from heart and vascular diseases, such as coronary heart disease, stroke, heart failure and peripheral vascular disease. There is also substantial evidence for a causal relationship between excess body weight and increased risk for a number of NHPA diseases such as Type 2 diabetes, gestational diabetes and some cancers such as colorectal cancer, prostate cancer and post-menopausal breast cancer.
Excess body weight is also associated with a range of other NHPA risk factors, such as high blood pressure, impaired glucose tolerance and high blood cholesterol. The risk of developing more than one NHPA disease or condition also increases with increasing levels of excess weight. Overweight was estimated to account for 4.3% of the total burden of disease in Australia in 1996.
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High blood pressure
High blood pressure (hypertension) is a condition that is defined by the WHO as when either the systolic blood pressure is 140 mmHg or more; or diastolic blood pressure is 90 mmHg or more. The term 'blood pressure' refers to the forces exerted by blood on the walls of the arteries and is measured as systolic pressure over diastolic pressure. Systolic blood pressure reflects the maximum pressure in the arteries when the heart muscle contracts to pump blood. Diastolic blood pressure reflects the minimum pressure in the arteries when the heart muscle relaxes.
High blood pressure is a major risk factor for a range of cardiovascular diseases. The risk of disease increases as the level of blood pressure increases. It can be controlled via changes in nutrition, weight, physical activity and medication. The burden of disease in Australia that can be attributed to high blood pressure was estimated to be more than 5% of the total burden in DALY terms among Australians in 1996.
Increased risk to two major forms of cardiovascular disease, coronary heart disease and stroke, as well as other serious complications are directly associated with high blood pressure. It can increase the risk of these two cardiovascular diseases by two to four times. High blood pressure is also associated with an increased risk of heart failure and peripheral vascular disease.
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High blood cholesterol
High blood cholesterol (hypercholesterolemia) means there is too much cholesterol (a fat-like substance) in the blood. This leads to the build up of cholesterol, on the walls of the arteries of the heart and other parts of the body, in a process called atherosclerosis, resulting in the arteries becoming clogged and having decreased or inhibited blood flow.
High blood cholesterol is a major risk factor for coronary heart disease, the single greatest cause of death and disability in Australia. It is also associated with an increased risk of ischaemic stroke, heart failure and peripheral vascular disease. For most people, a diet high in saturated fat is the main factor that raises blood cholesterol levels. High blood cholesterol accounted for almost 3% of the total burden of disease of Australians in 1996.
The set of indicators for risk factors covers the major underlying risk factors which commonly contribute to the NHPA diseases and conditions. This includes tobacco smoking, insufficient physical activity, excess body weight, high blood pressure, high blood cholesterol and diet and nutrition.
The list of National Health Priority Area Risk Factor indicators can be found here.
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Last reviewed by on 28 February 2005