Impact of an Antimicrobial Stewardship Initiative Focused on Staphylococcus aureus Bacteremia

BACKGROUND: Data exists to support a mortality reduction from S. aureus bacteremia with adherence to evidence-based recommendations. Therefore, our Antimicrobial Stewardship Team instituted a guideline focused on S. aureus bacteremia management. This study outlines improvements achieved through the implementation at an academic medical center. METHODS: A quasi-experimental approach evaluated pre-implementation (2014–15) and post-implementation (2015–17) periods. The Antimicrobial Stewardship Team provided a detailed standardized note and management guidelines. Adult patients with S. aureus bacteremia identified by a rapid diagnostic system were evaluated. Patients were excluded if discharged within 48 hours of a first positive blood culture or transitioned to comfort care. The primary outcome was all-cause 30-day mortality and secondary outcomes were total guideline adherence (TGA) and appropriateness of therapy. RESULTS: Overall, 263 patients (105 pre-implementation; 158 post-implementation) were included. No significant differences were observed in baseline characteristics (e.g., age, gender, ethnicity); however, the mean Pitt Bacteremia score was significantly lower in the post-implementation group (2 vs. 1; P = 0.01). Although no difference was observed in all-cause 30-day mortality (13% vs. 15%; P = 0.8), improved TGA (29% vs. 44%; P = 0.01) and appropriateness of therapy (68% vs. 74%; P = 0.26) were noted while duration of bacteremia decreased (3.6 days vs. 2.8 days; P = 0.02) in the post-implementation period. In uncomplicated bacteremia, TGA (15% vs. 38%; P = 0.02) and adequate duration of therapy (54% vs. 77%; P = 0.02) significantly improved. In complicated bacteremia, TGA (36% vs. 48%; P = 0.14) and targeted agents utilized (92% vs. 100%; P < 0.01) increased post-implementation. Additionally, achieving TGA significantly reduced all-cause 30-day mortality in complicated (33% vs. 1.5%; P < 0.01) and uncomplicated (26% vs. 5.6%; P = 0.01) bacteremia for the entire sample. CONCLUSION: The Antimicrobial Stewardship initiative significantly improved adherence to evidence-based guidelines for S. aureus bacteremia management. Though no impact on all-cause mortality was observed, a significant effect was noted when TGA was achieved. DISCLOSURES: All authors: No reported disclosures.