Impact of the COVID-19 pandemic on hospital antimicrobial consumption in Croatia

Objectives: The aim of the study was to assess the impact of the COVID-19 pandemic on antimicrobial consumption (AMC) in the hospital sector in Croatia by analysing data reported to the European Surveillance of Antimicrobial Consumption Network (ESAC-Net) between 2016 and 2020. Methods: AMC was measured as the number of DDDs/1000 inhabitants/day and as the number of DDDs/100 bed days. To assess trends, linear regression was performed. To assess the impact of the pandemic on AMC, the compound annual growth rate was calculated for the years preceding the pandemic based on which AMC for 2020 was forecasted and compared with the actual consumption. Results: While hospital AMC expressed as DDDs/1000 inhabitants/day between 2019 and 2020 decreased by 17%, when expressed as DDDs/100 bed days, an 8% increase was observed. Hospital consumption of antibacterials for systemic use in the 5 year period did not significantly change when expressed as DDDs/1000 inhabitants/day, while it statistically significantly increased when expressed as DDDs/100 bed days. An increasing trend in consumption of broad-spectrum antimicrobials was found. Conclusions: During the pandemic there was an increase in hospital AMC with a shift towards broad-spectrum antimicrobials requiring further in-depth qualitative analysis based on patient-level data. Contrasting results obtained using different denominators indicate that the metric DDDs/1000 inhabitants/day is not sensitive enough to evaluate hospital AMC. When assessing hospital AMC, the population under surveillance should be relevant for healthcare context. Antimicrobial stewardship remains one of the most important strategies to tackle antimicrobial resistance and antimicrobial surveillance methods must be as sensitive as possibl