Figure 4.

Concentrations of NGAL. Each graph shows the concentrations of NGAL (ng/L) for each of the categories of the PERFORM classification algorithm (top row) and of the SBI classification algorithm (bottom row) in the Alder Hey ED cohort (left), the Alder Hey PICU cohort (middle) and the St. Mary's hospital cohort (right). Each bar represents median concentration values, with the black lines representing the interquartile range, and the gray dots representing individual values. Overall significance for the PERFORM classification algorithm is given using the Kruskal Wallis test, and for the SBI classification using the Wilcoxon rank sum test. In addition, significance value for “definite bacterial” vs. “definite viral” of the PERFORM algorithm was calculated using the Wilcoxon rank sum test.