Mark Cobain on understanding cardiovascular risk

Amidst all the debate regarding CVD risk scores, Rod Jackson’s recent editorial ‘QRISK or Framingham for predicting cardiovascular risk?’  evaluated the usefulness of two risk scores: QRISK and Framingham.  It is worth recalling that it is nearly twenty years since Framingham, the UK’s most widely used risk score was developed. Is it time we reassess how we measure CVD risk?

With the emergence of high quality datasets in other countries there has been a move towards the development of region or country-specific CVD risk scores (such as the European SCORE project and the UK Q-RISK function).

These new risk scores have their pros and cons. However, as with all risk scores, they face a common problem – how to motivate people to take action and reduce their risk.

The notion that someone is at ‘low’ or ‘moderate’ risk when their risk is <20% makes sense in the context of cost effective drug treatment, but this risk threshold has no biological meaning.

Everyone in young and mid-life will benefit from maintaining or lowering blood pressure and cholesterol, quitting smoking and avoiding diabetes. The danger is that absolute risk levels below 20% are communicated as ‘low’ or ‘moderate’ risk can lead to false reassurance or a ‘certificate of good health’.

We incorporated Heart Age into the most recent CVD risk function publication from the Framingham Study. Heart Age is the age at which the estimated risk would be considered normal (the absolute risk associated with normal risk factors for the age). We find people are more likely to understand their absolute risk if it is presented to them as an age, especially in individuals (typically <20%) with a higher level of modifiable risk factors.

It is important to identify which risk scores best estimate absolute risk in the UK as important treatment decisions are made which have consequences for the individual and the public purse. However, no matter which function we choose, the same ‘modifiable risk factors’ are incorporated and we should not forget that unless we help people across the continuum of risk to understand and act to make changes to these risk factors the bills will keep rolling in.

Dr Mark Cobain, works for Unilever as a research platform director for Nutrition and Health and conducts research into risk communication and perception. He has worked with the Framingham Heart Study data to develop communication tools for CVD primary prevention (Heart Age: in collaboration with investigators from Boston University.