Effect and sustainability of a stepwise implemented multidisciplinary antimicrobial stewardship programme in a university hospital emergency department

Objectives: To explore effectiveness and sustainability of guideline adherence and antibiotic consumption after establishing treatment guidelines and initiating antimicrobial stewardship (AMS) ward rounds in a university hospital emergency department (ED). Methods: Data were gathered retrospectively from 2017 to 2021 in the LMU University Hospital in Munich, Germany. Four time periods were compared: P1 (pre-intervention period); P2 (distribution of guideline pocket cards); P3 (reassessment after 3 years); and P4 (refresher of guideline pocket cards and additional daily AMS ward rounds for different medical disciplines). Primary outcome was adherence to guideline pocket cards for community-acquired pneumonia, cystitis, pyelonephritis and COVID-19-associated bacterial pneumonia. Secondary outcomes were reduction in antibiotic consumption and adherence to AMS specialist recommendations. Results: The study included 1324 patients. Guideline adherence increased in P2 for each of the infectious diseases entities. After 3 years (P3), guideline adherence decreased again, but was mostly on a higher level than in P1. AMS ward rounds resulted in an additional increase in guideline adherence (P1/P2: 47% versus 58.6%, P = 0.005; P2/P3: 58.6% versus 57.3%, P = 0.750; P3/P4: 57.3% versus 72.5%, P < 0.001). Adherence increased significantly, not only during workdays but also on weekends/nightshifts. Adherence to AMS specialist recommendations was excellent (91.3%). We observed an increase in use of narrow-spectrum antibiotics and a decrease in the application of fluoroquinolones and cephalosporins. Conclusions: Establishing treatment guidelines in the ED is effective. However, positive effects can be diminished over time. Daily AMS ward rounds are useful, not only to restore but to further increase guideline adherence significantly.