1089. Implementation of a Febrile Neutropenia Management Algorithm on Antibiotic Use and Outcomes: An Interrupted Time Series Analysis

Background Febrile neutropenia (FN) is a common complication of cancer therapy and often necessitates prolonged antibiotic treatment. Antibiotic de-escalation can be challenging given tenuous clinical status. Furthermore, a microbiological or clinical etiology is identified in a minority of FN patients. In 2016 we implemented several evidence-based strategies to guide antibiotic use in high-risk FN patients including specifying vancomycin use indications, minimizing carbapenem escalation in stable patients with ongoing fevers, and defining antibiotic durations regardless of neutrophil count. The study objective was to characterize and evaluate our experience implementing these strategies on antibiotic use and clinical outcomes. Methods Interrupted time series analysis of all admissions to the Malignant Hematology service at the University of California, San Francisco between June 2014 and December 2018. The primary outcome was monthly days of therapy (DOT) per 1,000 patient-days of broad-spectrum IV antibiotics (aztreonam, cefepime, piperacillin–tazobactam, meropenem, and vancomycin). Secondary outcomes included DOT/1,000 patient-days for each IV antibiotic, incidence rates of bloodstream infections (BSI) and C. difficile infections (CDI), and in-hospital all-cause mortality. A segmented regression analysis was conducted to evaluate the impact of the FN management algorithm implementation on antibiotic use and clinical outcomes. Summary statistics and time series scatter plots were used to visualize the trends and outliers. Results 2319 unique patients with 6,788 encounters were included. The median (IQR) age was 59 (46–68) years and 60% were male. Regression results and time series plots are shown in Table 1 and Figures 1–3. Conclusion Implementation of an evidence-based FN management algorithm led to decreased vancomycin and meropenem use without a statistically significant impact on overall antibiotic use, CDI rates, or mortality.While BSI rates fluctuated in the 2 months post-implementation, rates returned to baseline thereafter. A multidisciplinary effort facilitated successful implementation of this stewardship project. This collaboration remains essential to addressing future antimicrobial management strategies in this population. Disclosures All authors: No reported disclosures.