Receiver operating characteristic curves of the PIRO, MEDS and APACHE II scores for predicting outcomes. (a) ICU admission. (b) Development of multiple organ dysfunction. (c) Twenty-eight-day mortality. APACHE, Acute Physiology and Chronic Health Evaluation; MEDS, Mortality in Emergency Department Sepsis; PIRO, predisposition (P), infection (I), response (R), and organ dysfunction (O).