Clinical and Economic Benefits of Antimicrobial Stewardship Programs in Hemodialysis Facilities: A Decision Analytic Model

Abstract

Background and objectives: Infections caused by multidrug-resistant organisms and Clostridium difficile are associated with substantial morbidity and mortality as well as excess costs. Antimicrobial exposure is the leading cause for these infections. Approximately 30% of antimicrobial doses administered in outpatient hemodialysis facilities are considered unnecessary. Implementing an antimicrobial stewardship program in outpatient hemodialysis facilities aimed at improving prescribing practices would have important clinical and economic benefits.

Design, setting, participants, & measurements: We developed a decision analytic model of antimicrobial use on the clinical and economic consequences of implementing a nationwide antimicrobial stewardship program in outpatient dialysis facilities. The main outcomes were total antimicrobial use, infections caused by multidrug-resistant organisms and C. difficile, infection-related mortality, and total costs. The analysis considered all patients on outpatient hemodialysis in the United States. The value of implementing antimicrobial stewardship programs, assuming a 20% decrease in unnecessary antimicrobial doses, was calculated as the incremental differences in clinical end points and cost outcomes. Event probabilities, antimicrobial regimens, and health care costs were informed by publicly available sources.

Results: On a national level, implementation of antimicrobial stewardship programs was predicted to result in 2182 fewer infections caused by multidrug-resistant organisms and C. difficile (4.8% reduction), 629 fewer infection-related deaths (4.6% reduction), and a cost savings of $106,893,517 (5.0% reduction) per year. The model was most sensitive to clinical parameters as opposed to antimicrobial costs.

Conclusions: The model suggests that implementation of antimicrobial stewardship programs in outpatient dialysis facilities would result in substantial reductions in infections caused by multidrug-resistant organisms and C. difficile, infection-related deaths, and costs.

Keywords: Anti-Bacterial Agents; Anti-Infective Agents; Antimicrobial Stewardship; Clostridium Infections; Clostridium difficile; Cost Savings; Enterococcus; Health Care Costs; Outpatients; Probability; cefazolin; chronic hemodialysis; costs; infections; maintenance hemodialysis; mortality; multidrug-resistant organisms; renal dialysis; vancomycin.

Graphical abstract

Figure 1.

Decision analytic tree simulates antimicrobial use under scenarios with and without an antimicrobial stewardship program. A, appropriate; CDI, Clostridium difficile infection; I, inappropriate; MDRGN, multidrug-resistant Gram negative; MDRO, multidrug-resistant organism; MRSA, methicillin-resistant Staphylococcus aureus; VRE, vancomycin-resistant enterococci.

Figure 2.

Tornado diagram displaying the univariable sensitivity analysis results (with ≥1% change around the base case) shows that the total annual incremental cost results are more sensitive to changes in event probabilities than to cost parameters. Parameters were tested with values that were 20% higher or lower than the base case. CDI, Clostridium difficile infection; MDRGN, multidrug-resistant Gram negative; MDRO, multidrug-resistant organism; MRSA, methicillin-resistant Staphylococcus aureus; VRE, vancomycin-resistant enterococci. A, B, E–J, and O, see Table 1 and Figure 1.

Figure 3.

Scenario analyses of different antimicrobial stewardship program effectiveness rates show greater cost savings in United States dollars (USD) and higher numbers of infections and infection-related deaths avoided with increasing program effectiveness.