Evaluation of the effectiveness of antimicrobial stewardship program: results from a ten-year study in a multidisciplinary hospital

Abstract

Objective. To evaluate the results of the implementation of antimicrobial stewardship (AMS) program in a multidisciplinary hospital. Materials and Methods. A retrospective intervention study was performed in the 600-bed multidisciplinary hospital of the Pirogov National Medical and Surgical Center (Moscow, Russia). The study included a number of sequential interventions, aimed at improving the prevention, diagnosis and treatment of infections, with an assessment of the following indicators dynamics: the structure of microorganisms isolated in the hospital, the level of resistance to antimicrobial drugs (AMD) among the pathogens of the ESKAPE group, the structure of prescribed AMD, as well as an assessment of clinical and economic consequences of antimicrobial resistance changes. For a comprehensive assessment of trend in antibiotic resistance and its connection with consumption of antibiotics, the drug resistance index (DRI) was used. DRI is based on the ratio of the level of resistance of the microorganism and the frequency of administration of AMD, potentially effective against this pathogen. The intervention started in 2013, so the data of 2012 (pre-intervention period) and 2022 were compared in this study. Results. The implementation of AMS program measures helped to reduce the relative frequency of ESKAPE group microorganisms in the structure of nosocomial infection pathogens in the hospital from 36.5% to 22% (p < 0.0001). The proportion of gram-negative (Gr-) isolates resistant to meropenem decreased from 32.4% to 10.9% (p < 0.0001). As a result of the introduction of AMS program, DDDh has been reduced almost three times: from 48.1 to 17.2 DDDh. The median duration of the AMT course in a specialized intensive care unit for the treatment of patients with nosocomial infections decreased from 12 to 8 days (p < 0.0001), the number of AMT days per 1 patient decreased from 7.7 to 4.2 (p < 0.0001). The proportion of ESKAPE pathogens in the structure of bloodstream infections in the hospital decreased from 53.1% to 26% (p < 0.0001), which led to decrease in mortality from 28.4% to 12.8%, (p = 0.012) and length of hospital stay from 31 to 22 days (p < 0.001) in this group of patients. Conclusions. The implementation of AMS program in a multidisciplinary hospital helps to reduce the frequency of inappropriate use of antimicrobial drugs and reduces the consumption of antibiotics, decrease the level of antimicrobial resistance, and in such way improves the results of treatment of patients with nosocomial infections.