Ethnic group differences in cardiovascular risk assessment scores: national cross-sectional study

Objectives. There are marked inequalities in cardiovascular disease (CVD) incidence and outcomes between ethnic groups. CVD risk scores are increasingly used in preventive medicine and should aim to accurately reflect differences between ethnic groups. Ethnicity, as an independent risk factor for CVD, can be accounted for in CVD risk scores primarily using two methods, either directly incorporating it as a risk factor in the algorithm or through a post hoc adjustment of risk. We aim to compare these two methods in terms of their prediction of CVD across ethnic groups using representative national data from England. Design. A cross-sectional study using data from the Health Survey for England. We measured ethnic group differences in risk estimation between the QRISK2, which includes ethnicity and Joint British Societies 2 (JBS2) algorithm, which uses post hoc risk adjustment factor for South Asian men. Results. The QRISK2 score produces lower median estimates of CVD risk than JBS2 overall (6.6% [lower quartile-upper quartile (LQ-UQ) = 4.0-18.6] compared with 9.3% [LQ-UQ = 2.3-16.9]). Differences in median risk scores are significantly greater in South Asian men (7.5% [LQ-UQ = 3.6-12.5]) compared with White men (3.0% [LQ-UQ = 0.7-5.9]). Using QRISK2, 19.1% [95% confidence interval (CI) = 16.2-22.0] fewer South Asian men are designated at high risk compared with 8.8% (95% CI = 5.9-7.8) fewer in White men. Across all ethnic groups, women had a lower median QRISK2 score (0.72 [LQ-UQ = - 0.6 to 2.13]), although relatively more (2.0% [95% CI = 1.4-2.6]) were at high risk than with JBS2. Conclusions. Ethnicity is an important CVD risk factor. Current scoring tools used in the UK produce significantly different estimates of CVD risk within ethnic groups, particularly in South Asian men. Work to accurately estimate CVD risk in ethnic minority groups is important if CVD prevention programmes are to address health inequalities.