279. A Decision Tree Using Clinical Characteristics to Predict a Hospitalized Child’s Risk of a Multidrug-Resistant Gram-Negative Bloodstream Infection

BACKGROUND: As the threat of multidrug-resistant Gram-negative (MDRGN) bacteria rises, recognizing children at high risk of bloodstream infections with bacteria resistant to commonly prescribed empiric antibiotics is critical. We developed a decision tree to predict which pediatric bloodstream infections were due to MDRGN bacteria resistant to cefepime or piperacillin–tazobactam, commonly prescribed empiric antibiotics. METHODS: We conducted a longitudinal retrospective cohort study at the Children’s Hospital of Pittsburgh including all admitted patients with a Gram-negative bloodstream infection from June 2009 to June 2015. Episodes of bloodstream infection were considered unique if at least 30 days had elapsed since the previous bloodstream infection. Logistic regression was performed to identify notable risk factors. A decision tree describing the risk of an MDRGN infection was developed using recursive partitioning based on clinical characteristics available at the time of presentation. RESULTS: Six hundred eighty-nine episodes of Gram-negative bloodstream infections occurred during the study period among 387 patients. Twenty-eight percent of infections were multidrug-resistant (MDR). The decision tree separated patients into higher or lower risk groups based on history of prior carbapenem treatment for seven or more days, having a prior MDR infection within 6 months, intestinal transplant status, age 3 years or older, and seven or more prior episodes of bacteremia. The sensitivity to classify high risk of MDR was 46% and the specificity was 92% based on leave one out cross validation. For patients who had more than one episode, 30% of initially non-MDR infections were subsequently MDR. CONCLUSION: A decision tree using readily available clinical characteristics may be helpful to identify pediatric patients at higher risk of bloodstream infection due to an MDRGN organism resistant to common empirical antibiotic therapy. DISCLOSURES: All authors: No reported disclosures.