Australian CVD risk calculator
Introduction
Cardiovascular disease (CVD) is an umbrella term that includes heart, stroke, and blood vessel diseases. It is one of Australia’s largest health problems and a leading cause of death. An updated Australian 'Guideline for assessing and managing cardiovascular disease risk' was released in 2023. This update was released alongside a new Australian CVD risk calculator, by the Australian Heart Foundation with the Commonwealth of Australia (CA/DHAC 2023).
The Australian CVD risk calculator estimates the chance of an individual developing CVD within the next 5 years using data for multiple risk factors. Assessing CVD risk based on the combined effect of risk factors is more accurate than looking at risk factors individually and allows for more tailored risk factor management for each person (NVDPA 2012; Nelson 2020).
This page provides information for users who are interested in utilising the Australian CVD risk calculator when analysing results from the National Health Measures Survey (NHMS) and the National Aboriginal and Torres Strait Islander Health Measures Survey (NATSIHMS).
For more information on biomedical measures of CVD, refer to Cardiovascular disease (CVD) biomarkers.
Definition
The Australian CVD risk calculator produces estimated 5-year CVD risk scores, expressed as a percentage representing the person’s probability of dying or being hospitalised due to myocardial infarction, angina, other coronary heart disease, stroke, transient ischaemic attack, peripheral vascular disease, congestive heart failure or other ischaemic CVD-related conditions within the next 5 years.
The 2023 'Guideline for assessing and managing cardiovascular disease risk' replaces the previous 2012 version 'Guidelines for the management of absolute cardiovascular disease risk' (CA/DHAC 2023). The 2023 guideline incorporates a new risk calculator with more risk variables included and updated evidence-based recommendations on assessing and managing CVD risk to reduce cardiovascular events. For more information about the Australian CVD risk calculator, see the AusCVDRisk website.
The evidence base for the 2023 Australian CVD risk calculator has been updated since the previous 2012 Australian absolute CVD risk calculator was published, as have the age groups of people to whom it applies.
The 2023 Australian CVD risk calculator uses a predictive equation (PREDICT-CVD19) to estimate CVD risk, based on cohort health studies of the New Zealand population undertaken from 2002-2012 (Wells et al. 2017). This evidence base is considered more suitable for the Australian population than that used in the 2012 calculator, which used the Framingham predictive equation based on health studies on a US population undertaken in the 1970s (NVDPA 2012; NIH n.d.).
Analysing biomedical study data with the Australian CVD risk calculator
At the time of publication, the ABS has not published CVD risk profiles from the IHMHS. However, the ABS recognises that some users may be interested in using the Australian CVD risk calculator to analyse results.
The applicable population for the Australian CVD risk calculator is persons aged 45–79 years and 30–79 years for Aboriginal and Torres Strait Islander peoples who agreed to participate in the NHMS or NATSIHMS and provided a blood sample. Persons aged 80 years and over or with known CVD should be excluded from data analysis.
To conduct analysis using the 2023 Australian CVD risk calculator, users will need to utilise both biomedical study data items and data from other IHMHS surveys. However, the IHMHS does not collect all the data inputs required for the Australian CVD risk calculator. A summary of available inputs is provided in the table below.
| Variables used in Australian CVD risk calculator | Required input | Availability in the IHMHS |
|---|---|---|
| Age | Yes | Yes |
| Sex at birth | Yes | Yes |
| Smoking status(a) | Yes | Yes |
| Systolic blood pressure (BP) | Yes | Yes |
| Ratio of total cholesterol to high-density lipoprotein (HDL) cholesterol | Yes | Available only in the NHMS or the NATSIHMS. |
| Diabetes status | Yes | Available only in the NHMS or the NATSIHMS. |
Use of CVD medicines within the last 6 months including:
| Yes | The NHMS or the NATSIHMS collected information on cholesterol lowering prescription medication, but the period of use is not included in the question to participants. The National Health Survey collected prescription medication information sourced from the Pharmaceutical Benefits Scheme. For more information, see National Health Survey methodology, 2022. The National Aboriginal and Torres Strait Islander Health Survey collected information about medication use for participants in non-remote areas. For more information, see National Aboriginal and Torres Strait Islander Health Survey methodology, 2022–23. Other surveys in the IHMHS did not collect information on medicines. |
| Socio-Economic Indexes for Areas (SEIFA) quintile | No | Yes |
| Medical history of atrial fibrillation | No | Not available |
| Years since diabetes diagnosis(b) | Yes | Not directly available, however 'age when first told had diabetes' is asked of people who self-reported a diabetes diagnosis. |
| Glycated haemoglobin (HbA1c)(b) | Yes | Available only in the NHMS or the NATSIHMS. |
| Urinary albumin/creatinine ratio (ACR)(b) | Yes | Available only in the NHMS or the NATSIHMS. |
| Estimated globular filtration rate (eGFR)(b) | Yes | Available only in the NHMS or the NATSIHMS. |
| Body mass index (BMI)(b) | Yes | Yes |
| Use of insulin within the last 6 months(b) | Yes | Not available |
- Information on smoking status obtained from the IHMHS was not as detailed as required in the CVD risk calculator so can only be used as a proxy measure.
- Only required as additional diabetes-specific variables for people with Type 2 diabetes.
There is a diabetes-specific equation in the Australian CVD risk calculator that provides a more accurate estimate of CVD risk for people with Type 2 diabetes, but additional data inputs are required (see table above). The ABS advises that analysis using the diabetes-specific equation to assess the CVD risk for people with diabetes cannot be undertaken using IHMHS data as not all the required data inputs were collected.
Interpretation
Points to be considered when interpreting analysis with the 2023 Australian CVD risk calculator for this topic include the following:
- The calculator is not applicable for use with people with a high CVD risk (i.e. people with known CVD, chronic kidney disease or with a confirmed diagnosis of familial hypercholesterolaemia).
- Information was not collected on the history of atrial fibrillation, but this is an optional input into the calculator.
- Information on smoking status obtained from the IHMHS was not as detailed as required in the calculator so can only be used as a proxy measure.
- The equation on which the calculator is based has not been validated for people with Type 1 diabetes, or people aged 80 years and over.
- Whilst the biomedical indicators, uACR and eGFR, have been shown to independently improve prediction of cardiovascular events, they are only included as variables in the diabetes-specific equation for the calculator due to lack of availability of data in the reference population (New Zealand PREDICT cohort).
- In addition to physiological and lifestyle factors, socioeconomic status is also associated with increased CVD risk. Including socioeconomic status in risk prediction improves accuracy, compared with using risk factors alone.
- The data from this topic should be used with caution when comparing results from other studies using different biomedical test methods and/or CVD risk calculators.
Comparison to other CVD risk data
The ABS did not publish results on CVD risk profiles using the 2012 Australian absolute CVD risk calculator in previous biomedical collections. However, CVD risk profiles were available in the DataLab microdata.
Data generated using the 2023 Australian CVD risk calculator should not be directly compared to that from the previous 2012 calculator as the input parameters are different and reference population has changed (CA/DHAC 2023). An overview of the difference between the two calculators is provided in the table below.
| 2012 Australian absolute CVD risk calculator | 2023 Australian CVD risk calculator | |
|---|---|---|
| Purpose | Measures absolute risk of CVD within next 5 years | Estimates risk of CVD within 5-year period |
| Basis of calculation | Framingham-based equation | PREDICT-1 Equation |
| Reference population | Equation was based on Framingham Heart Study of US population (1970s) - original equation used to predict CVD risk for US populations within next 10 years, adapted for Australian populations to estimate CVD risk within 5 years (NIH n.d.). | Adapted from NZ large population cohort study (2002-2012) to Australian populations (Wells et al. 2017). |
| Risk groups | For use by:
Not for use by:
| For use by:
Separate diabetes-specific equation for people diabetes used to estimate CVD risk (additional data inputs required). Not for use by:
|
Data inputs
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Optional data inputs
Additional data inputs for diabetes-specific equation
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| Risk categories for reporting purposes |
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| Limitations | The Framingham Heart Study was based mainly on ethnically European, people of higher socio-economic status, not representative of younger age groups and different ethnicities. It is an older study (1970s) with US populations that had different diets, levels of smoking and other risk factors compared to today’s Australian population. It overestimated CVD risk for the general population but underestimated CVD risk for Aboriginal and/or Torres Strait Islander peoples. It may have underestimated CVD risk for other low socio-economic groups. | The PREDICT-1 equation is not validated for people with Type 1 diabetes, people aged ≥80 years old. CVD risk is higher in more socio-economically disadvantaged groups, so the CVD risk estimate is more accurate if postcode is added (linked to SEIFA quintile in the calculator). The determinants included in SEIFA may not fully capture the environmental, social, political and economic determinants of CVD and health inequality experienced by Aboriginal and/or Torres Strait Islander people. |
References
Commonwealth of Australia as represented by the Department of Health and Aged Care (CA/DHAC) (2023), Australian Guideline for assessing and managing cardiovascular disease risk, AusCVDRisk, Australian Government, accessed 20/02/2025.
National Institutes of Health (NIH) (n.d.), Framingham Heart Study: Laying the Foundation for Preventive Health Care, NIH, accessed 20/02/2025.
National Vascular Disease Prevention Alliance (NVDPA) (2012), Guidelines for the management of absolute cardiovascular disease risk [PDF 4458 KB], Heart Foundation, accessed 20/02/2025.
Nelson MR (2020), Absolute cardiovascular disease risk and the use of the Australian cardiovascular disease risk calculator, Australian Journal of General Practice, 49(8):471–473, accessed 20/02/2025.
Wells S, Riddell T, Kerr A, Pylypchuk R, Chelimo C, Marshall R, Exeter DJ, Mehta S, Harrison J, Kyle C, Grey C, Metcalf, Warren J, Kenealy T, Drury PL, Harwood M, Bramley D, Gala G, Jackson R (2017), Cohort Profile: The PREDICT Cardiovascular Disease Cohort in New Zealand Primary Care, (PREDICT-CVD 19), International Journal of Epidemiology, 46(1):22, accessed 20/02/2025.