A comprehensive assessment of carbapenem use across 90 Veterans Health Administration hospitals with defined stewardship strategies for carbapenems.

OBJECTIVES 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 analysed a cohort of all patients hospitalized at Veterans Health Administration (VHA) acute care hospitals during 2016 and a mandatory survey 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). Carbapenem use was compared 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 cases. Auditors assessed carbapenem appropriateness with an assessment score on Day 4 of therapy. RESULTS There were 429 062 admissions in 90 sites (24 NS, 8 PAF, 58 RP). Carbapenem use was lower at PAF than NS sites [rate ratio (RR) 0.6 (95% CI 0.4-0.9); P = 0.01] but similar between RP and NS sites. Carbapenem prescribing was considered appropriate/acceptable in 215 (50.6%) of the reviewed cases. Assessment scores were lower (i.e. better) at RP than NS sites (mean 2.3 versus 2.7; P < 0.01) but did not differ significantly between NS and PAF sites. ID consultations were more common at PAF/RP than NS sites (51% versus 29%; P < 0.01). ID consultations were associated with lower (i.e. better) assessment scores (mean 2.3 versus 2.6; P < 0.01). CONCLUSIONS In this VHA cohort, PAF strategies were associated with lower carbapenem use and ID consultation and RP strategies were associated with more appropriate carbapenem prescribing. AS and ID consultations may work complementarily and hospitals could leverage both to optimize carbapenem use.