QRISK3

Click here for an online Qrisk calculator (QRISK3)

• Hippisley-Cox et al have derived a cardiovascular disease risk score (QRISK) for the United Kingdom and validated its performance against the established Framingham cardiovascular disease algorithm and a Scottish score (ASSIGN)
  • the authors undertook a prospective open cohort study using routinely collected data from general practice in order to develop their model
    • the practices involved in this study were UK practices which contributed to the QRESEARCH database
      • derivation cohort consisted of 1.28 million patients, aged 35-74 years, registered at 318 practices between 1 January 1995 and 1 April 2007 and who were free of diabetes and existing cardiovascular disease
  • a validation cohort was used to test the risk estimates derived from the QRISK model
    • validation cohort consisted of 0.61 million patients from 160 practices
• the developers of the QRISK model included the following model variables:
  • age, sex, ratio of serum cholesterol to high density lipoprotein levels, systolic blood pressure, body mass index, family history of premature cardiovascular disease, smoking status, Townsend deprivation score, and use of at least one blood pressure treatment
    • the final QRISK model also included an interaction term between systolic blood pressure and blood pressure treatment
    • left ventricular hypertrophy was omitted from the final model as the prevalence of recording was low and its inclusion made little difference to the overall model
    • area measure of ethnicity was also omitted from the final model since it did not improve the model fit over and above the inclusion of the area measure of deprivation
• from data from the validation cohort:
  • in patients aged 35-74
    • the Framingham algorithm over-predicted cardiovascular disease risk at 10 years by 35%, ASSIGN by 36%, and QRISK by 0.4%
    • QRISK predicted 9% of patients aged 35-74 to be at high risk compared with 13% for the Framingham equation and 14% for ASSIGN
    • QRISK estimated that 34% of women and 73% of men aged 64-75 would be at high risk compared with 24% and 86% according to the Framingham equation
  • the study results suggest that UK estimates of patients at high risk of cardiovascular disease
    • on the basis of QRISK, there were 3.2 million patients at high risk in 2005, compared with 4.71 million for the Framingham equation and 5.1 million for ASSIGN
    • overall, QRISK would reclassify about 1 in 10 patients from high to low risk or vice versa compared with the Framingham algorithm
• the QRISK developers concluded that (1):
  • QRISK performed at least as well as the Framingham model for discrimination and was better calibrated to the UK population than either the Framingham model or ASSIGN
  • QRISK is likely to provide more appropriate risk estimates to help identify high risk patients on the basis of age, sex, and social deprivation

QRISK2

• the authors built on our previous risk prediction algorithm (QRISK1)to develop a revised algorithm that incorporates self assigned ethnicity as well as a range of other potentially relevant conditions associated with cardiovascular risk such as type 2 diabetes, treated hypertension, rheumatoid arthritis, renal disease, and atrial fibrillation (QRISK2)
  • list of variables included in the QRISK2 calculation:
    • age
    • sex
    • cholesterol/HDL ratio
    • blood pressure
    • diabetes
    • smoking status
    • self assigned ethnicity
    • family history of premature coronary heart disease in a first degree relative under the age of 60
    • deprivation (measured using the Townsend deprivation score)
    • blood pressure treatment
    • body mass index
    • rheumatoid arthritis
    • chronic kidney disease
    • atrial fibrillation
• study evidence showed that by Incorporating ethnicity, deprivation, and other clinical conditions into the QRISK2 algorithm for risk of cardiovascular disease improves the accuracy of identification of those at high risk in a nationally representative population. At the 20% threshold, QRISK2 is likely to be a more efficient and equitable tool for treatment decisions for the primary prevention of cardiovascular disease (3)
• NICE suggest the use of QRISK2 in assessment risk of cardiovascular disease in the primary prevention setting (4)

Notes:

• Framingham
  • Framingham risk equations have major limitations
    • Framingham cohort is almost entirely white and recalibration may be needed in more ethnically diverse populations
    • Framingham risk equations were developed during the peak incidence of cardiovascular disease in America
      • may over-estimate risk by up to 50% in contemporary northern European populations where the incidence of cardiovascular disease is lower
    • does not include factors such as social deprivation, body mass index, family history of cardiovascular disease, and current treatment with antihypertensives
• QRISK versus Framingham
  • QRISK includes standard as well as additional risk factors for cardiovascular disease, such as deprivation, family history of premature coronary heart disease, body mass index, and the effect of existing antihypertensive treatment (1)
    • inclusion of antihypertensive treatment at baseline is of relevance to 1 in 10 of the population
  • a validation study concluded that (2):
    • QRISK is better calibrated to the UK population than Framingham and has better discrimination. Study results suggest that QRISK is likely to provide more appropriate risk estimates than Framingham to help identify patients at high risk of CVD in the UK

Reference:

• (1) Hippisley-Cox J et al. Derivation and validation of QRISK, a new cardiovascular disease risk score for the United Kingdom: prospective open cohort study.BMJ. 2007 Jul 21;335(7611):136
• (2) Hippisley-Cox J et al. Performance of the QRISK cardiovascular risk prediction algorithm in an independent UK sample of patients from general practice: a validation study. Heart. 2008 Jan;94(1):34-9.
• (3) Hippisley-Cox J et al. Predicting cardiovascular risk in England and Wales: prospective derivation and validation of QRISK2. BMJ. 2008 Jun 28;336(7659):1475-82.
• (4) NICE (July 2014). Lipid modification: cardiovascular risk assessment and the modification of blood lipids for the primary and secondary prevention of cardiovascular disease

Last edited 02/2021 and last reviewed 02/2021