Table 3 Comparison of C-index and net reclassification index (NRI) across models. Models are predicting cardiovascular disease mortality in the testing dataset of the National Health and Nutrition Examination Survey

Cox Proportional Hazards Model

 Model 1: Traditional Predictors^b

0.845

10

 Model 2: + Blood Metals^c

0.847

0.23 (0.09, 0.38)

13

 Model 3: + Urinary Metals^d

0.843

0.21 (0.07, 0.35)

28

 Model 4: + Metals quadratic/interaction terms^e

0.773

0.35 (0.21, 0.48)

177

Elastic-Net

 Model 5: Traditional Predictors^b

0.828

10

 Model 6: + Blood Metals^c

0.830

0.66 (0.52, 0.80)

12

 Model 7: + Urinary Metals^d

0.830

0.51 (0.37, 0.64)

14

 Model 8: + Metals quadratic/interaction terms^e

0.830

0.76 (0.62, 0.90)

13

Survival Random Forest

 Model 9: Traditional Predictors^b

0.833

10

 Model 10: + Blood Metals^c

0.826

-0.18 (-0.32, -0.04)

13

 Model 11: + Urinary Metals^d

0.826

-0.49 (-0.63, -0.35)

28