889. Another Respiratory Culture Nudge Improves Pneumonia Prescribing

Abstract Background Nudging with purposeful, directed comments to microbiology results appears to improve antibiotic prescribing. The study objective was to assess prescribing before and after a β-lactamase interpretative comment for Haemophilus influenzae and Moraxella catarrhalis lower respiratory tract infections (LRTI). Methods IRB approved, quasi-experiment. Included: hospitalized adults prescribed antibiotics for H. influenzae or M. catarrhalis LRTI from 8/20/17-3/19/19 (pre-group) and 3/20/19-8/20/21 (post-group). Excluded: non-LRTI, polymicrobial infections, antibiotic prophylaxis, IgE-mediated β-lactam allergy. Intervention- automated comment for β-lactamase negative: “this organism is predictably susceptible to ampicillin or amoxicillin”; β-lactamase positive: “this organism is predictably susceptible to ampicillin-sulbactam or amoxicillin-clavulanate”. Primary endpoint: optimal de-escalation, defined as ampicillin, amoxicillin or aminopenicillins for β-lactamase negative; amoxicillin/clavulanate or ampicillin/sulbactam for β-lactamase positive. Secondary endpoints: clinical success, antibiotic duration, time to de-escalation. Sample size: 200 calculated for 30% difference in de-escalation, α=0.05, β=0.2. Results Enrolled 100 pre- and 101 post. 61% vs. 64% male; 63% vs. 73% community-acquired pneumonia; 20% vs. 15% hospital acquired pneumonia; 17% vs. 12% ventilator associated pneumonia; 81% vs. 77% H. influenzae; 46% vs. 52% β-lactamase positive; 4% vs. 7% non-IgE β-lactam allergy, respectively. Optimal de-escalation: 19 (19%) pre-, 51 (51%) post- (p< 0.001). After adjustment, post-group associated with 5-fold increased odds of optimal de-escalation (Table 1). Secondary endpoints pre and post: median (IQR) duration 7 (6, 8) and 7 days (6, 10); median time to de-escalation: 1 (0, 2) and 0 (0, 1) days; clinical success: 79 (79%) and 81 (80%). Conclusion An automated, β-lactamase nudge was associated with a reduction in definitive broad-spectrum antibiotics. Stewardship programs should continue to evaluate persuasive comments as an effective and efficient intervention. Disclosures All Authors: No reported disclosures.