Hospital antibiotic consumption—an interrupted time series analysis of the early and late phases of the COVID-19 pandemic in Poland, a retrospective study

Background COVID-19 has been challenging for the entire healthcare system, due to the lack of sufficient treatment protocols, especially during initial phases and as regards antibiotic use. The aim of this study was to identify the trends of antimicrobial consumption in one of the largest tertiary hospitals in Poland during COVID-19. Methods This is a retrospective study conducted at the University Hospital in Krakow, Poland, between Feb/Mar 2020 and Feb 2021. It included 250 patients. All included patients were hospitalized due to COVID-19 with confirmed SARS-CoV-2 infection without bacterial co-infections during the first phase of COVID-19 in Europe and following 3-month intervals: five equal groups of patients in each. COVID severity and antibiotic consumption were assessed according to WHO recommendations. Results In total 178 (71.2%) patients received antibiotics with a incidence rate of laboratory-confirmed healthcare-associated infection (LC-HAI) was 20%. The severity of COVID-19 was mild in 40.8%, moderate in 36.8%, and severe in 22.4% cases. The ABX administration was significantly higher for intensive care unit (ICU) patients (97.7% vs. 65.7%). Length of hospital stay was extended for patients with ABX (22.3 vs. 14.4 days). In total, 3 946.87 DDDs of ABXs were used, including 1512.63 DDDs in ICU, accounting for 780.94 and 2522.73 per 1000 hospital days, respectively. The median values of antibiotic DDD were greater among patients with severe COVID-19 than others (20.92). Patients admitted at the beginning of the pandemic (Feb/Mar, May 2020) had significantly greater values of median DDDs, respectively, 25.3 and 16.0 compared to those admitted in later (Aug, Nov 2020; Feb 2021), respectively, 11.0, 11.0 and 11.2, but the proportion of patients receiving ABX therapy was lower in Feb/Mar and May 2020 (62.0 and 48.0%), whereas the highest during the late period of the pandemic, i.e., in Aug, Nov. 2020 and Feb. 2021 (78% and both 84.0%). Conclusions Data suggest great misuse of antibiotics without relevant data about HAIs. Almost all ICU patients received some antibiotics, which was correlated with prolonged hospitalization.