Comparison of antimicrobial consumption indicators in the emergency department

Monitoring antimicrobial use in the emergency department is complex due to the wide variety of existing indicators. We evaluated the differences between various indicators used to evaluate antimicrobial use in these units.

Retrospective analysis of administrative data from all adult patients admitted to an emergency unit (2019-2024). Aggregated quarterly data included the percentage of patients treated, DDDs/100 admissions, DDD/100 patients-day and DOT/100 admissions. An autoregressive integrated moving average (ARIMA) model was used to investigate the association between DDD/100 admissions and the other antimicrobial use indicators.

Annual median antimicrobial drug use measured by DDDs/100 admissions was 11.7 (IQR 10.8-12.4). Significant differences in antimicrobial consumption correlation were noted when comparing DDD/100 admissions and DDD/100 patient-days for cephalosporins, lincosamides, and carbapenems. Significant differences in the comparison between DDD and DOT were found for imipenem, clindamycin, piperacillin-tazobactam, gentamicin, and vancomycin.

Aggregate antimicrobial use measured by DDDs or DOTs is consistent, though discrepancies in correlation may occur for antibiotics with multiple daily doses. DDD/100 admissions is a suitable indicator, but complementing it with DDD/100 patient-days, DOT, and percentage of patients receiving antibiotics provides valuable information for monitoring antimicrobial use.