The overuse of antimicrobials during the COVID-19 pandemic: data from 25 general hospitals in Shanxi, China

BACKGROUND: During the coronavirus disease 2019 (COVID-19) pandemic, widespread empirical antimicrobial use was reported globally, often without confirmed bacterial infection. This study aimed to assess antimicrobial prescribing patterns, bacterial coinfection rates, and clinical outcomes among inpatients during the Omicron surge in Shanxi Province, China. METHODS: We conducted a multicentre retrospective study using data from 25 hospitals. Non-surgical inpatients discharged between December 1, 2022, and January 31, 2023, were included. Patients were categorized by COVID-19 status and antimicrobial use. Antimicrobial consumption was measured using defined daily doses (DDDs), days of therapy (DOT), and antimicrobial use density (AUD). Clinical outcomes, microbiological data, and adverse events were analyzed. RESULTS: Among the 2064 inpatients included, 701 (34.0%) were diagnosed with COVID-19. Of these, 511 (72.9%) received antimicrobial therapy, while only 382 (54.5%) had a documented bacterial infection. Microbiological testing was positive in only 123 (6.0%) patients, yielding 139 isolates, of which 21 (15.1%) were multidrug-resistant. Consistently, COVID-19-positive patients were exposed to broad-spectrum agents more frequently: the proportions of both highly-restricted and restricted antimicrobials were significantly higher than in COVID-19-negative patients (4.7% vs. 2.8% and 68.2% vs. 61.9%, respectively; P < 0.05). Overall antimicrobial pressure was also greater in the positive group: antimicrobial-use density reached 84.28 vs. 47.07 DDDs/100 bed-days (P < 0.001), and days of therapy were 811.06 vs. 541.43 /1000 patient-days (P < 0.001). These differences translated into higher costs (median total hospitalization expense CNY 8013 vs. CNY 6447; P < 0.001) and prolonged stays (36.0% stayed 11–20 days vs. 22.4%; P < 0.001). Mortality did not differ across groups (P = 0.779). CONCLUSION: This study highlights the excessive use of antimicrobials in COVID-19 inpatients, often without confirmed bacterial infection. This overuse did not improve outcomes but contributed to increased healthcare costs and antimicrobial resistance risk. Rational antimicrobial management and improved diagnostic practices are crucial to combat this challenge in health care settings. CLINICAL TRIAL: Not applicable.