211. A Comprehensive Assessment of Carbapenem Use across 90 Veterans Health Administration Hospitals with Defined Stewardship Strategies for Carbapenems

Background Carbapenems are an important target for antimicrobial stewardship (AS) efforts. In this study, we sought to compare different hospital-based strategies for improving carbapenem use. Methods We analyzed a cohort of all patients hospitalized at Veterans Health Administration (VHA) acute-care hospitals during 2016 and mandatory survey data that characterized each hospital’s carbapenem-specific AS strategy into one of three types: no strategy (NS), prospective audit-and feedback (PAF), or restrictive policies (RP). Sites that could not be classified were excluded. Inpatient carbapenem use was compared across strategies using risk-adjusted generalized estimating equations that accounted for clustering within hospitals. Two Infectious Disease (ID) physicians independently performed manual chart reviews in 425 randomly-selected carbapenem-treated cases (100 for PAF/NS and 225 for RP). Auditors assessed for the presence of ID consultation and carbapenem appropriateness on day 4 of therapy. Assessments were categorized as follows: appropriate (1), acceptable (2), suboptimal (3), unnecessary (4) and inappropriate (5). Assessment scores across strategies were compared with the Kruskal-Wallis test. Results There were 429,602 admissions in 90 sites (8 PAF, 24 NS, 58 RP). Median carbapenem use across sites was 17.4 (IQR 8.6–28.4) days of therapy/1,000 days-present. Inpatient carbapenem use was lower at PAF than NS sites [RR 0.67 (95% CI, 0.46–0.98); p=0.04] but similar between RP and NS sites [RR 0.86 (95% CI, 0.61–1.22); p=0.41]. Carbapenem use was considered appropriate or acceptable in 215 (50.6%) of the reviewed cases. Assessment scores were higher (i.e. worse) at NS than RP sites (mean 2.7 vs 2.3; p< 0.01) but did not differ significantly between NS and PAF sites (mean 2.7 vs 2.5; p=0.14). ID consultations were more common at PAF/RP than NS sites (51% vs 29%; p< 0.01). ID consultations were associated with lower (i.e. better) assessment scores (2.3 vs. 2.6; p< 0.01). Conclusion In this VHA cohort, AS strategies and ID consultations were associated with either less or more appropriate carbapenem-prescribing. The use of AS and ID consultations may be complementary, and hospitals could leverage both to optimize carbapenem use. Disclosures Daniel J. Livorsi, MD, MSc, Merck and Company, Inc (Research Grant or Support)