Trends in and Predictors of Carbapenem Consumption across North American Hospitals: Results from a Multicenter Survey by the MAD-ID Research Network

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Antimicrobial agents and chemotherapy


Introduction: We sought to define trends in and predictors of carbapenem consumption across community, teaching, and university-affiliated hospitals in the United States and Canada.Materials and Methods. We conducted a retrospective, multi-center, survey of carbapenem and broad-spectrum non-carbapenem beta-lactam consumption between 1/2011 and 12/2013. Consumption was tabulated as defined daily doses (DDD) or as days of therapy (DOT) per 1000 patient days (PD). Multivariate mixed-effects models were explored, and final model goodness-of-fit was assessed by regressions of observed vs. predicted values and residual distributions.Results. 20 acute-care hospitals responded. Centers treated adult (n=19/20) and pediatric/neonatal patients (n=17/20). The majority of centers were non-profit (n=17/20) and not affiliated with medical/teaching institutions (n=11/20). Median (IQR) carbapenem consumption was 38.8 (17.4-95.7) DDD/1000 PD and 29.7 (19.2-40.1) DOT/1000 PD, overall. Carbapenem consumption was well described by a multivariate linear mixed-effects model (fixed-effects: R(2)=0.792; fixed+random-effects: R(2)=0.974). Carbapenem consumption increased by 1.91-fold/quarter from 48.6 DDD/1000 PD (P=0.004) and by 0.056-fold/quarter from 45.7 DOT/1000 PD (P=0.93) over the study period. Non-carbapenem consumption was independently related to increasing carbapenem consumption (beta=0.31 for increasing non-carbapenem beta-lactam consumption; P<0.001). Regular antibiogram publication and promotion of IV to PO conversion independently affected carbapenem consumption rates. In the final model, 58.5% of the observed variance in consumption was attributable to between-hospital differences.Conclusions Carbapenem consumption across 20 North American hospitals was highly variable, and the observed variability was correlated with hospital-specific demographics. Additional studies focusing on the drivers of hospital-specific carbapenem consumption are needed to determine whether these rates are justifiable.

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