Australia's CVD risk calculator shifted millions into the 'grey zone'

There is a number sitting in your medical records — probably from the last time your GP did a health check — called your CVD risk score. It tells you, as a percentage, the likelihood of a heart attack or stroke in the next five years. And as of 2023, the tool used to calculate that number in Australia changed significantly.

A study just published in the Medical Journal of Australia has quantified what that change actually means at a population level: for people aged 45–74, the new calculator is reclassifying far more people into the intermediate-risk zone than the old one did.

That sounds technical. But it has a direct implication for what your GP should be discussing with you in a routine health check — and whether a conversation that was closed is now worth reopening.

The old calculator was American, and it was wrong for Australians

The previous CVD risk tool used in Australia was based on the Framingham study — a decades-old American dataset from Massachusetts. It was the best tool available for a long time, but it had a known limitation: it was calibrated for a US population with higher baseline cardiovascular mortality than Australians. The result was that it systematically overestimated CVD risk for most Australians.

The updated calculator, validated in the MJA study and built on data from more than 400,000 New Zealanders with Australian recalibration, corrects this. It also includes a diabetes-specific equation — which matters because cardiovascular risk in people with diabetes wasn’t accurately captured in the old tool.

Here is what the reclassification looks like in practice:

• High risk (above 15% five-year event risk): dropped from 17.6% to 9.7% of the study population
• Intermediate risk (5–15%): nearly doubled, from 11.6% to 26.4%
• Low risk (below 5%): increased from 64.5% to 76.4%

In plain terms: many people who were told they were at high risk — and may have been started on statins or other preventive medication on that basis — are more accurately classified as intermediate risk. And a separate group who were previously low-risk may now sit in the intermediate zone.

What intermediate risk actually means

The intermediate zone is not a bureaucratic nuisance category. It is where medicine is supposed to do its best work.

Low risk means: modify lifestyle, come back for a check in a few years, the likelihood of an event is small. High risk means: here are the medications that will meaningfully reduce your event rate, the evidence is strong enough that the conversation is mostly about which ones and when. Intermediate risk means neither of those scripts applies cleanly. It is the zone where your risk level alone doesn’t decide the conversation — your full picture does.

As Melbourne GP Associate Professor Ralph Audehm puts it in the newsGP commentary on this study: calculators are “a good first step” but what matters is “knowledge of the whole person.” Factors like chronic kidney disease, family history of premature heart disease, prior blood pressure trends, and even stress load aren’t captured in the calculator — and they can move an intermediate score in either direction.

This is actually good news for patients. Not because being reclassified to intermediate risk feels good — it doesn’t, necessarily — but because the intermediate zone is where shared decision-making properly lives. A number that was previously telling your GP to act can now open a conversation instead.

Both-and: hold the uncertainty

Here is the tension worth naming honestly.

A doctor who moved a patient from intermediate to high risk on the old calculator — and started a statin on that basis — wasn’t wrong at the time. They were using the best tool available. The updated calculator isn’t a retrospective error. It’s an improvement.

But it does mean that some people are on preventive cardiovascular medication that, calculated on updated figures, they may not require. And it means some people who were dismissed as low risk have quietly moved to intermediate — and may benefit from a review they haven’t been prompted to seek.

Neither group is wrong to ask questions.

The RACGP guidelines for cardiovascular risk management are in the process of being updated to reflect the new calculator. The direction is clear. The detail is in progress.

2 cents: what this means for your terrain this week

Women in their 40s and 50s are particularly worth flagging here. Cardiovascular risk climbs steeply in the perimenopause transition — oestrogen has a protective role that diminishes as levels fall — and the decade between 45 and 55 is when the recalculation matters most. If your last formal health check used the old Framingham-based tool, a reassessment gives you a more accurate current number.

Specifically worth asking at your next GP appointment:

1. “Has my CVD risk been calculated using the updated Australian tool, not the old Framingham one?”
2. “Given the reclassification data, does my score change how you’d approach the conversation about medication?”
3. If you’re already on a statin: “Does my current risk level still justify ongoing treatment, or is a review warranted?”

These are not challenging questions. They are exactly the questions the updated evidence base supports you asking.

Your cardiovascular risk is not fixed — it is a calculation made with a tool, at a point in time, against population data. Better data produces a better estimate. Asking for the updated one is entirely reasonable.

Verdict: yes — worth knowing about.

---

Sources cited

1. More Australians at ‘intermediate’ risk of CVD: Study — newsGP, 20 Oct 2026
2. Updated CVD risk calculator study — Medical Journal of Australia
3. RACGP Guidelines for absolute cardiovascular risk management