In fact, the improvements of risk prediction/classification by the ERS are similar to the AUC improvements for coronary heart disease risk prediction by genetic risk scores (GRS) found in the Atherosclerosis Risk in Communities (ARIC) (from 0.742 to 0.749), Rotterdam Study (from 0.729 to 0.734) and Framingham Offspring Study (from 0.773 to 0.775) [49]. We also point out that for GWAS studies, a polygenic risk score has also contributed very modestly to risk prediction as measured by increment in AUC or R2, however, similar risk stratification properties across the quintiles of genetic risk scores have been noted [23]. Nonetheless, our findings imply that ERS can better determine potential risk stratification where individuals are at increased risk of high lipid levels and related cardio-metabolic diseases than single pollutant approaches. The proposed ERS may allow us to identify susceptible subpopulations where targeted interventions are necessary and could have the greatest benefits [27].
