Els van de Vijver

48 98.4) vs. 72.7% (CI: 63.8 to 81.0) compared to calprotectin. The numerical data are shown in supplementary file 2. Figure 4 I Diagnostic accuracy measures of the calprotectin (grey square) and calgranulin-C test (black diamond) to diagnose IBD in children. Graph A shows the results when predefined thresholds are used (resp. 50 μg/g and 0.75 μg/g). Graph B shows the results when ROC-based optimal thresholds (resp. 400 μg/g and 0.75 μg/g) are used. Whiskers represent the 95% credible interval. Optimal (ROC-based) thresholds The optimal (ROC-based) threshold for calprotectin was 400 μg/g, while the optimal threshold of calgranulin-C was equal to the pre-defined threshold (0.75 μg/g). The difference in specificity and positive predictive value disappeared when optimal thresholds were compared. A graphical representation of the equivalence between calprotectin and calgranulin-C for the complete study cohort (verified with either reference test) is shown in figure 4B . Concordant vs. discordant pairs Figure 5 shows that 306 of 337 pairs of calprotectin and calgranulin-C results were concordant (91%). Discordant pairs (n=31 (9%)) are described in detail in supplementary file 4. Thirteen Chapter 3