QRISK2 Cardiovascular Risk Score

This is an innovative new cardiovascular disease risk calculator, based on the QRESEARCH database of anonymised UK primary care patients. In 2003 the database was established jointly by University of Nottingham and EMIS GP computing company, and now contains over 10 million patients (over 550 practices) spread throughout the UK, with encrypted records being updated daily.¹

Using this data, a cohort of 1.28 million patients without evidence of diabetes mellitus or cardiovascular disease (CVD) was identified, and followed up for >5 years looking for the first development of CVD as an endpoint.²

The current version of the calculator (QRISK2) uses the following parameters (if known - missing values are calculated by a complex averaging procedure called multiple imputation):^3,4

• Patient age (35-74)
• Patient gender
• Current smoker (yes/no)
• Family history of heart disease aged <60 (yes/no)
• Existing treatment with blood pressure agent (yes/no)
• Postcode (postcode related Townsend score) - an area measure of deprivation
• Body mass index (height and weight)
• Systolic blood pressure (use current not pre-treatment value)
• Total and HDL cholesterol
• Self assigned ethnicity
• Rheumatoid arthritis
• Chronic kidney disease
• Atrial fibrillation

The calculator is available at http://www.qrisk.org/

Comparing with the existing Joint British Societies Cardiovascular Risk Calculation (which is based on Framingham data and the one currently recommended by NICE):⁵

Advantages

• Calculated risk is calibrated to the contemporary UK population, so is likely to provide more appropriate risk estimates to help identify high risk patients.
• Calculated risk is adjusted for additional variables - social deprivation and current treatment with antihypertensives.
• It has been validated in the UK using an alternative research database.⁶

QRISK identifies a different high risk group of patients than the Framingham equation, with one in ten patients being reclassified into high or low risk

Disadvantages

• Although the calculator uses a complicated algorithm to estimate missing variables, cholesterol risk behaves more as expected if full values are used.
• Still can't be used legitimately for "what if" scenarios

There is also a specific ETHRISK calculator based on Framingham data which may be appropriate for British black and ethnic minority groups.⁷

Although NICE still recommend the Framingham based primary cardiovascular risk calculator, in practice it may be appropriate to feed in a specific patient's data into a number of calculators and use the slightly different results to fuel any subsequent discussions about risk factor modification with that particular patient.