Improved use of antibiotics following implementation of antimicrobial stewardship in a neonatal intensive care unit.

Introduction: Inappropriate antibiotic use in infants can have multiple adverse effects and contribute to the development of bacteria resistant to antimicrobials. Antimicrobial stewardship programs can reduce unnecessary antibiotic use in children. The aim of this study was to evaluate the effect of an antimicrobial stewardship program implemented in 2017 in the Neonatal Intensive Care Unit (NICU) at The Children's Hospital Iceland.

Materials and methods: The study included all infants who were admitted to the NICU during the study period (January 1^st 2012-October 31^st 2020). Data was collected from hospital records. Three periods were defined: preimplementation (2012-2014), peri-implementation (2015-2016) and postimplementation (2017-October 2020). Antibiotic use was quantified using days of therapy (DOT) per 1000 bed days (BD). For statistical analysis the pre- and postimplementation periods were compared.

Results: Antibiotics were administered in 38.6% (1372) of admissions to the NICU during the study period. Antimicrobial use per year decreased from 584.6 to 317.1 DOT/1000 BD per year (P < 0.001). Use of broad-spectrum antibiotics decreased significantly. The average number of BD per month decreased from 297.8 to 220.9 BD/month (P = 0.0096). There were no significant changes in the length of stay for each infant or the proportion of readmissions or retreatment.

Conclusion: Increased awareness of appropriate use of antimicrobials in the NICU led to shorter treatments and less use of broad-spectrum antibiotics. No increase in adverse effects such as readmissions or retreatment was observed.