Evaluation of DRS test performance. (A) Boxplot of DRS values from bacterial and viral infected samples using 1-transcript signature (IFI44L). Horizontal red dotted line indicates the optimal threshold value. (B) Boxplot of DRS values from bacterial and viral samples using 2-transcript signature. Horizontal blue dotted line indicates the optimal threshold value. (C) ROC curves generated from 2-transcript (blue) and 1-transcript (red) (IFI44L) DRS with AUC values and 95% CI. We used a t-test to evaluate statistical differences in DRS values between bacterial and viral patients in panels (A,B). The box represents the interquartile range (25th to the 75th) containing the middle 50% of the data, the line in the box represents the median, and the whiskers represent the ranges for the bottom 25% and the top 25% of the data values, excluding outliers.