Fig. 3

Final results from classification analyses using random forests in a two-stage cross-validation scheme with 20 inner and 20 outer loops (Additional file 1: Figure S1). Left panel: Ten most important metabolites ranked by a weighted (area under the curve) mean Gini index (orange triangle). Boxplots indicate distribution across 20 outer runs. Right panel: Receiver operating characteristic (ROC) curve and boxplot of the area under the curve from 20 outer loops. Overlapping ROCs are displayed by darker shades