Consumption of anti-meticillin-resistant Staphylococcus aureus antibiotics in Swiss hospitals is associated with antibiotic stewardship measures

Background: Consumption of antibiotics active against meticillin-resistant Staphylococcus aureus (MRSA) has been described in numerous European studies. However, the underlying predictors of consumption are still poorly understood. Aim: To describe the consumption of anti-MRSA antibiotics (daptomycin, intravenous glycopeptides, linezolid) in Switzerland over time and to identify underlying predictor variables. Methods: A retrospective observational multi-centre study was conducted in 21 Swiss hospitals over a period of 11 years (2009-2019). Multiple linear regression models were built to identify regional and hospital-specific predictor variables affecting the consumption of anti-MRSA antibiotics. Findings: Consumption of anti-MRSA antibiotics increased between 2009 and 2019 from 12.7 to 24.5 defined daily doses per 1000 bed-days (+93%). In the first model presented, which includes data of the whole study period, the following variables were associated with higher anti-MRSA antibiotic consumption: number of MRSA cases (P < 0.01), year (P < 0.01), hospital type (tertiary care university hospitals vs others, P < 0.01), hospital department (intensive care unit vs others, P < 0.01) and linguistic region (French vs German and German vs Italian, P < 0.01). In a second model including data from a query on hospital policies in place in 2019, the presence of an antibiotic stewardship group (P < 0.01) and prescription restrictions (P < 0.01) were associated with consumption of antiMRSA antibiotics. Conclusion: Our study shows that both the presence of an antibiotic stewardship group and the implementation of prescription restrictions, i.e. factors that can be controlled by the hospital itself, were associated with a lower consumption of anti-MRSA antibiotics. (c) 2021 The Authors. Published by Elsevier Ltd on behalf of The Healthcare Infection Society. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).