Table 2.
FDA and SVM models that achieved the highest AUROC following cross-validation (CV) for each number of potential biomarkers. CV AUROC was calculated by using leave-one-out cross-validation and performing multiple imputations when needed (except in the *** model). Sensitivity and specificity are provided for the optimal operating point of the CV ROC curve.
| Number of Markers | Method | Model Constituents | Fitted AUROC |
CV AUROC | Sensitivity (TPR) | Specificity (TNR) |
|---|---|---|---|---|---|---|
| 2 | FDA | Free sulfate (plasma) Uridine (plasma) |
0.92 | 0.94 | 0.94 | 0.86 |
| 3 | FDA | Free sulfate (plasma) Uridine (plasma) Beta-amino isobutyrate |
0.95 | 0.96 | 0.92 | 0.89 |
| 4 | FDA | Free sulfate (plasma) Uridine (plasma) Homo cystine Beta-amino isobutyrate |
0.96 | 0.97 | 0.93 | 0.91 |
| 5 | FDA | Free sulfate (plasma) Uridine (plasma) Initial homo cystine Beta-amino isobutyrate Serum magnesium |
0.96 | 0.98 | 0.95 | 0.95 |
| 5 *** | FDA | Free sulfate (plasma) Uridine (plasma) Beta-amino isobutyrate Tryptophan (plasma) Homo cystine (plasma) |
0.96 | 0.97 | 0.93 | 0.89 |
| 5 ‡ | FDA | Glutathione (plasma) Uridine (plasma) Thallium (urine) Glutamate (plasma) Homo cystine (plasma) |
0.94 | 0.95 | 0.98 | 0.75 |
| 5 | SVM | Free sulfate (plasma) Magnesium (Serum) Homo cystine (plasma) Uridine (plasma) Beta-amino isobutyrate |
1.00 | 0.92 | 0.91 | 0.92 |
| 6 | FDA | Free sulfate (plasma) Uridine (plasma) Homo cystine (plasma) Beta-amino isobutyrate Serum magnesium RBC copper |
0.97 | 0.98 | 0.95 | 0.95 |
*** Represents cases in which only 27 metabolites without missing data were utilized. ‡ Represents cases in which sulfate metabolites were excluded.