Independent external validation of the QRISK3 cardiovascular disease risk prediction model using UK Biobank

Abstract

Objective: To externally evaluate the performance of QRISK3 for predicting 10 year risk of cardiovascular disease (CVD) in the UK Biobank cohort.

Methods: We used data from the UK Biobank, a large-scale prospective cohort study of 403 370 participants aged 40-69 years recruited between 2006 and 2010 in the UK. We included participants with no previous history of CVD or statin treatment and defined the outcome to be the first occurrence of coronary heart disease, ischaemic stroke or transient ischaemic attack, derived from linked hospital inpatient records and death registrations.

Results: Our study population included 233 233 women and 170 137 men, with 9295 and 13 028 incident CVD events, respectively. Overall, QRISK3 had moderate discrimination for UK Biobank participants (Harrell's C-statistic 0.722 in women and 0.697 in men) and discrimination declined by age (<0.62 in all participants aged 65 years or older). QRISK3 systematically overpredicted CVD risk in UK Biobank, particularly in older participants, by as much as 20%.

Conclusions: QRISK3 had moderate overall discrimination in UK Biobank, which was best in younger participants. The observed CVD risk for UK Biobank participants was lower than that predicted by QRISK3, particularly for older participants. It may be necessary to recalibrate QRISK3 or use an alternate model in studies that require accurate CVD risk prediction in UK Biobank.

Keywords: Epidemiology; Risk Factors.

Figure 1

Flow chart of the female and male population used for this study after exclusions for missing Townsend deprivation scores, statin prescription and previous diagnoses of CVD. CVD, cardiovascular disease.

Figure 2

Calibration of QRISK3 at 10 years for female and male participants of UK Biobank overall. The cumulative Kaplan-Meier observed CVD probability in each 10th of risk is denoted by the orange circular markers and the mean predicted QRISK3 score in each 10th of risk is denoted by the blue square markers. CVD, cardiovascular disease.

Figure 3

Calibration of QRISK3 at 10 years for female and male participants of UK Biobank in each age group. The cumulative Kaplan-Meier observed CVD probability in each 10th of risk is denoted by the orange circular markers and the mean predicted QRISK3 score in each 10th of risk is denoted by the blue square markers.