Framingham has ‘no clinical utility’ for predicting cardiovascular events

GPs should use an alternative cardiovascular risk prediction score to Framingham to assess patients for statin treatment, as the algorithm has ‘no clinical utility' compared with the latest version of QRISK, researchers have concluded.

The damning conclusions of the study provide solid evidence for GPs to switch to use the QRISK2 equation, as it identified up to five more cases per thousand patients than Framingham.

Current NICE guidelines leave it open to GPs to decide which cardiovascular risk score they wish to use, including a modified version of Framingham or QRISK2.

UK researchers looked at over two million patients, aged between 30 and 74 years and with no previous diagnosis of cardiovascular disease, recorded on The Health Improvement Network (THIN) database. The median follow-up was five years, and each patient's first diagnosis of cardiovascular disease was recorded.

The independent analysis found the 2011 version of QRISK2 identified five more cases of patients at high risk of cardiovascular disease per 1,000 in males, compared with the NICE version of the Framingham equation.

For women, QRISK2-2011 identified two more cases of high risk patients per 1,000 than Framingham.

This suggested an increased accuracy in estimating cardiovascular risk in UK patients, and did not come with any significant increase in the number treated unnecessarily.

When predicted risk was compared with observed risk, all three QRISK models showed good agreement across all age groups. But the NICE Framingham equation showed a near-constant over-prediction of about 5% across all age groups in men.

The authors from the University of Oxford concluded: ‘If the Framingham equation is to continue to be used and doctors advised to treat patients if their predicted risk is 20% or higher, then it is necessary for it to be recalibrated and updated to reflect current characteristics of the UK population.'

Dr John Ashcroft, a GP in Derbyshire and member of the Derbyshire CHD committee, said a switch to QRISK would be a wise choice.

He said: ‘It includes risk factors that are important and are often over looked, or difficult to factor in, including family history, atrial fibrillation, and renal dysfunction.'

But he said that it might have implications for the current NICE threshold for primary prevention set at a 20% ten-year risk of CVD

He said: ‘NICE recommendations to treat risk at 20% was set too high, but it appears the use of Framingham that over assesses risk effectively has cancelled out some of this "error".'

‘NICE are starting the process of reviewing their guidance, but it will be July 2014 before we see the result. Hopefully this time they will get it right, but in the meantime I will use QRISK2, and discuss with my patients about treating down to a 10% risk.'

QRISK versus Framingham