The absolute risk method has been promoted internationally for many years. This approach moves away from the traditional single risk factor assessment, to a more accurate prediction of an individual's overall cardiovascular disease (CVD) risk. By using a more accurate prediction, health providers can make more informed decisions about how to care for their patients. Absolute risk assessment provides a quick and effective way to identify those who are most at risk of CVD, and therefore those who can benefit the most from intensive management.

The Guidelines for the management of absolute cardiovascular disease risk, released in May 2012,  incorporates and builds on the previous NVDPA Guidelines for the Assessment of Absolute Cardiovascular Disease Risk (2009) and consolidates a number of other evidence-based guidelines to provide clear guidance to prevent first-ever CVD events.

The Guidelines for the management of absolute CVD risk and the Quick reference guide for health professionals can be accessed here.

Further information on the guidelines can be found on the Heart Foundation's website here.

On the home page of this website you can use the calculator provided to measure absolute risk of having a CVD event within 5 years.

Step 1

Enter a value for each variable listed on the calculator. These variables are:

Sex: Please indicate whether you are male or female (biological gender).

Age: Please enter the age in years. The calculator can be used for all Australian adults between the ages of 45-74 years. For Aboriginal and Torres Strait Islander peoples the calculator can be used from 35 years. For those over the age of 74 years please enter an age of 74 which will provide the risk, expressed as a percentage % of having a CVD event in the next 5 years.

Systolic blood pressure: Please enter your systolic blood pressure. Blood pressure is recorded as two numbers, for example 120 over 80 (120/80 mmHg). The first number (120 in the example) is called systolic blood pressure. This indicates the pressure in the arteries as the heart squeezes blood out during each beat. In this calculator you can enter a systolic blood pressure value up to 179 mmHg (above this is considered as high risk and doesn't need a calculation).

Smoking status: Please indicate whether you are a smoker. A smoker is defined as currently smoking or quit within the last year.

Total cholesterol: Please enter your total cholesterol level. There are different types of cholesterol in the human body. Your  total cholesterol  reading is a value that adds together the different types of cholesterol in your body. In this calculator you can enter a cholesterol value up to 7.5 mmol/L (above this is considered as high risk and doesn't need a calculation). When you get a blood test that includes your cholesterol, it will give you a reading for your total cholesterol level.

HDL cholesterol: Please enter your HDL cholesterol level. HDL cholesterol stands for High Density Lipoprotein cholesterol. This cholesterol is sometimes described as "good cholesterol" because higher levels of HDL appear to have a protective effect on heart disease, while lower levels of HDL increase the risk of getting heart disease. When you get a blood test that includes your cholesterol, it will give you a reading for your HDL cholesterol level.

Diabetes: Please indicate whether you have diabetes  it doesn't matter what type. Diabetes increases the chances of getting heart disease. The World Health Organisation definition for the diagnosis of diabetes includes a fasting blood sugar of 7 mmol/L, or a 2-hour blood sugar reading of 11.1mmol/L.

ECG-LVH: Please indicate whether you have ECG-LVH. ECG-LVH stands for Left Ventricular Hypertrophy (LVH) as diagnosed by an Echocardiogram (ECG). In the original cohort of Framingham, which this calculator is based on, it was found that those who had LVH had a higher risk of CVD. You can find out if you have LVH by visiting your doctor.

Step 2

Once you have entered a value for each of the above variables click on Go. The number that comes up on the right-hand side of the screen is your absolute risk score. You can find out what this risk score means by going to the 'Your risk score'  page on this website.

Step 3

If you want to change one or more of your risk factors to see how they might affect your risk of CVD, click on compare and change any of the variables. Then click go to see the score compared with your first score.

The most recently recorded pre-treatment value should ideally be used for individuals taking antihypertensive medication. Where this is not possible decisions about increasing or decreasing therapy should be made with their doctor (rather than calculating risk on treatment).

It may take some time for a recent non-smoker to return to a non-smoker level of health, therefore this type of patient should be categorised as smoker in the risk assessment calculation.

The absolute risk guidelines were developed according to the standards outlined in the NHMRC Standards and Procedures for Externally Developed Guidelines (2007)

Guidelines for the Assessment of Absolute Cardiovascular Disease Risk:

1. A systematic review was completed in order to formulate recommendations (using literature up to April 2006). The resulting report, titled Technical report: review of the evidence and evidence-based recommendations for practice is available on NVDPA member websites.
2. Where the systematic review identified insufficient evidence to answer a clinical question, a consensus-based approach was used to formulate recommendations. A steering group with broad representation completed this. Consensus statements were formulated based on available evidence (using literature up to August 2007) and expert clinical judgement.
3. Public consultation process to review the full guideline (April-May 2008).
4. Independent review of the full guideline by the National Health and Medical Research Council (NHMRC) (July-October 2008).
5. Finalisation of the guideline based on feedback from the review.
6. Endorsement by the NHMRC, received in January 2009.

Guidelines for the Management of Absolute Cardiovascular Disease Risk:

1. A systematic literature review was completed to answer pre-defined clinical questions. The search used literature from 2006 to June 2010 for the assessment of CVD risk, and 2002 to June 2010 for the remaining questions relating to management of absolute CVD risk. Hand searching was conducted between June 2010 and May 2011. More information on the search strategy is available in the full guideline.
2. Where the systematic review identified insufficient evidence to answer a clinical question, a consensus-based approach was used to formulate recommendations. A steering group with broad representation completed this. Consensus statements were formulated based on available evidence and expert clinical judgement.
3. The public consultation process invited feedback during a month-long period in April 2011. A broad group of stakeholders, networks and consumer organisations were also invited to comment.
4. Independent review of the full guideline by the National Health and Medical Research council (NHMRC).
5. Endorsement by RACGP and NHMRC, received in April 2012.

The absolute risk calculator and risk charts are based on the prediction equation known as the Framingham Risk Equation. This equation has been tested for its validity and has shown to have good predictive ability. The systematic reviews for both the assessment and management guidelines compared the predictive ability of different absolute cardiovascular disease risk assessment methods. The reviews found that the Framingham Risk Equation was the most thoroughly tested method of assessing absolute cardiovascular risk (in adults not known to have diabetes or existing cardiovascular disease) and had higher or equivalent predictive ability compared with other absolute cardiovascular disease risk assessment methods.

For more detailed information see Chapter 1 of the NVDPA Guidelines for the Management of Cardiovascular Disease Risk.

The Framingham Risk Equation is a predictive equation borne out of the Framingham Heart Study, which started in 1948 and has been operational for more than 60 years. You can read about the Framingham Heart Study by clicking here.

The Framingham Risk Equation was developed for several cardiovascular disease endpoints by Anderson and colleagues in 1991. The citations for the relevant scientific papers are:

Anderson KM, Odell PM, Wilson PW, Kannel WB. Cardiovascular disease risk profiles. Am Heart J 1991; 121 (1 Pt 2): 293-298.

Anderson KM, Wilson PW, Odell PM, et al. An updated coronary risk profile. A statement for professionals. Circulation 1991; 83: 356-362.

Absolute risk is a method of determining an individual's overall heart and stroke risk level over a defined time period (for example, 5 or 10 years). In the NVDPA guidelines, absolute risk is defined as the chance of an individual experiencing a cardiovascular event (including a heart attack or stroke), over a 5 year period, expressed as a percentage.

In contrast, relative risk is a ratio of the rate of events in the population exposed to a risk factor compared with the rate among the population not exposed to this risk factor. It tells you little about an individual's actual risk over time.

Management that is based on absolute risk has the potential to deliver treatments to those who can benefit the most, because absolute risk is a more meaningful way of measuring a person's actual risk.

Some well known risk factors for cardiovascular disease, such as obesity, are not included in the risk calculations. This is not because they are not important for reducing cardiovascular disease risk, but because either research showed that they did not increase the predictive value of the final equation, or the Framingham Risk Equation has not been specifically assessed in these populations (e.g. the overweight and obese).

Nevertheless, the guidelines do recognise that consideration of these factors is important when completing a comprehensive assessment of absolute risk. The guidelines recommend that a comprehensive risk assessment include:

• those factors assessed in the risk calculator, as well as
• consideration of other issues such as the patient's socioeconomic status, family history, cultural and ethnic identity, waist circumference, body mass index, nutrition, alcohol intake, physical activity level and any other related conditions (kidney function, familial hypercholesterolaemia, and atrial fibrillation).

The Framingham Risk Equation has not been specifically assessed across diverse populations. The NVDPA does recognise that consideration of this is important when completing a comprehensive assessment of absolute risk.

The absolute risk calculator is based on the Framingham Risk Equation. Separate Framingham equations were developed for use of systolic blood pressure and diastolic blood pressure. Except for the blood pressure covariate, the models are identical for both blood pressures and for most outcomes differences in predictive probabilities are slight. However, because the log likelihoods are slightly higher when systolic blood pressure is used, it has been recommended by Anderson et al. (1991) that systolic blood pressure be used where possible.

While both the Australian and New Zealand risk charts are based on the Framingham Risk Equation, you will see some differences in the Australian charts, including:

1. The charts include values for systolic blood pressure up to 179 mmHg, rather than 180 mmHg. This is because individuals with a systolic blood pressure of 180 mmHg or more should be considered at increased absolute risk of cardiovascular disease and do not require risk calculation using the risk charts.
2. A footnote has been added indicating that individuals with a total cholesterol level greater than 7.5 mmol/L should be considered at increased absolute risk of cardiovascular disease and do not require risk calculation using the risk charts.
3. The charts are categorised by diabetes status, rather than sex.
4. A note has been added that individuals with diabetes and age over 60 should be considered at increased absolute risk of cardiovascular disease and do not require risk calculation using the risk charts.

The NVDPA Guidelines for the Management of Absolute Cardiovascular Disease Risk provides the recommended assessment pathway, interventions, targets and follow-up. It incorporates the recommendations from the assessment guidelines and consolidates recommendations for lifestyle and drug therapy for cholesterol and blood pressure lowering into a single guideline.

The Guidelines for the management of absolute CVD risk and the Quick reference guide for health professionals can be accessed here.

High risk of CVD begins early among Aboriginal and Torres Strait Islander peoples and is mainly due to diabetes and renal disease. 1 in 7 adults aged 18-74 years are at high absolute CVD risk. CVD, chronic kidney disease and diabetes are often associated with each other and share risk factors, and the presence of one can exacerbate the other. 

Assessment of absolute cardiovascular risk should begin earlier for Aboriginal and Torres Strait Islander patients. 

From the age of 18 years at the latest, undertake combined early screening for diabetes, chronic kidney disease and CVD risk factors. This should include assessment of blood glucose level or glycated haemoglobin, estimated glomerular filtration rate, serum lipids, urine albumin to creatinine ratio, and other risk factors such as blood pressure, history of familial hypercholesterolaemia, and smoking status. 

From the age of 30 years at the latest, undertake assessment of absolute CVD risk using an Australian CVD risk calculator. 

Note: The Australian absolute CVD risk calculator does not allow calculations using an age of less than 35 years. For these ages it is recommended that an age of 35 is used for the purposes of the calculation. As the Framingham Risk Equation underestimates the risk of CVD events in Aboriginal and Torres Strait Islander people aged less than 35 years, the use of a slightly older age is unlikely to significantly inflate CVD risk.