Els van de Vijver

41 sapovirus). Laboratory technicians were blinded to symptoms filled in on the website. The attending paediatricians were informed of the calprotectin and PCR result for bacteria and Giardia lamblia, but they were blinded to the calgranulin-C and PCR result for viruses. The predefined thresholds used in this study were 50 µg/g for calprotectin and 0.75 µg/g for calgranulin-C. Reference tests We used an automated IBD Risk Stratifier ( figure 1 ) to advice paediatricians whether patients should proceed to endoscopy (the preferred reference standard) for verification of IBD, or whether they should be followed up clinically for possible latent IBD to become visible (the alternative reference standard). Head-to-head comparison Calgranulin C and Calprotectin 41