Targeted antimicrobial stewardship (AMS) is associated with improved prescribing quality and reduced broad-spectrum antibiotic use, according to a recent Danish study, supporting structured, pharmacist-inclusive interventions in hospital practice.
The prospective, quasi-experimental before-and-after study evaluated the impact of a multidisciplinary AMS programme on piperacillin–tazobactam (TZP) use at Copenhagen University Hospital in Denmark.
Published in the Journal of Hospital Infection, the study aimed to reduce broad-spectrum antibiotic use, improve prescribing quality and assess clinical safety following AMS implementation.
Following a pilot phase from September to December 2022 in which baseline TZP prescribing was assessed, the intervention was introduced in January 2023 and included prospective audit and feedback, education and monthly departmental reports.
The AMS team comprised infectious diseases specialists, a clinical microbiologist and a clinical pharmacist, supported by ward-level physician champions.
TZP and multidisciplinary AMS
Across the three-year study period, 156,035 hospital admissions were analysed, including 92,346 (59.2%) in departments exposed to AMS. The study population consisted of adult inpatients across medical and surgical specialties, with comparator departments receiving no AMS input.
Implementation of the AMS programme was associated with a 19.5% reduction in TZP use in participating departments (95% CI: −25.5 to −13.5%; P < 0.001), while its use increased by 26.7% in non-AMS departments (95% CI: 18.6–34.9%; P < 0.001).
Prescribing quality also improved significantly. Point prevalence survey data for 262 TZP prescriptions demonstrated increased guideline adherence (44.2% to 66.9%), improved documentation of indication (50.7% to 75.8%), treatment planning (4.3% to 30.6%) and reassessment within 72 hours (16.7% to 49.2%).
The intervention also drove a shift towards narrower-spectrum therapy, with increased use of benzylpenicillin (14.2%), ampicillin (20.2%) and aminoglycosides (36.4%) in AMS departments.
Importantly, clinical safety outcomes were maintained. In-hospital mortality remained stable (6.0% vs 6.1%; P = 0.962), while 30-day readmission decreased from 11.6% to 10.2% (P = 0.0001).
Evaluating stewardship impact
The authors acknowledged that the non-randomised design and structural differences between AMS and non-AMS departments introduced potential confounding. In addition, the point prevalence surveys were limited to two time points in 2021 and 2022, and the relatively small sample size may also restrict the statistical power of the results.
Patient-level data, microbiological outcomes and spectrum-based antibiotic metrics were not available, restricting assessment of appropriateness and resistance trends, they added. Therefore, future research should incorporate these to better evaluate stewardship impact.
Overall, the findings suggested that a structured, multidisciplinary AMS programme can reduce broad-spectrum antibiotic use and improve prescribing quality without adverse safety signals, reinforcing the value of pharmacist-led stewardship activities in routine hospital care.
The authors also highlighted that sustained impact required ongoing audit and feedback, noting reduced effect in 2024 when intervention intensity declined, and the need to integrate AMS into routine workflows instead of short-term project structures.
At ESCMID Global 2025, Dr Carolina Garcia-Vidal, infectious diseases consultant at Hospital Clinic Barcelona, Spain, discussed how the novel antibiotic combination cefepime/enmetazobactam outperformed piperacillin/tazobactam in clinical cure and microbiological eradication in clinical trial data.
She also called for greater inclusion of these microbiome considerations in clinical guidelines.
Reference
Holler JG et al. Impact of a multi-disciplinary antimicrobial stewardship programme on piperacillin–tazobactam use at a Danish university hospital: a before-and-after interventional study. J Hosp Infect. 2026;170:81–91.
This article was originally published by our sister publication Hospital Healthcare Europe.
