IL6 and systemic inflammatory response syndrome: A model including four clinical parameters (length of PICU stay until onset of non-infectious SIRS/sepsis, presence of a central line, core temperature, cumulative number of sepsis and non-infectious SIRS episodes prior to diagnosis) as well as four laboratory parameters (IL-6, platelet count, PCT, CRP) was identified as the best model showing an out-of-bag area under the curve (OOB-AUC) of 0.82 (Fig. 2, Table 2).