Impact of Pharmacist-Led Antimicrobial Stewardship on Antibiotic Use in Intensive Care: A Prospective Audit and...

Antimicrobial stewardship programs (ASPs) aim to optimize antimicrobial use in intensive care units (ICUs), where high antimicrobial consumption, antimicrobial resistance, and complex pharmacokinetics complicate therapy.

This prospective, observational, pre-post study was conducted in the ICU of a tertiary hospital in Türkiye over 6 months (October 2024-April 2025), comprising a 3-month pre-ASP observation period and a 3-month ASP period. During the ASP period, a clinical pharmacist integrated within a interprofessional team, including infectious disease physicians, conducted prospective audit and feedback in collaboration with the ICU team. Antimicrobial appropriateness was evaluated as the primary objective, while antimicrobial consumption (days of therapy [DOT] and length of therapy [LOT]), intervention characteristics, acceptance rates, and 30-day mortality were assessed as secondary objectives.

A total of 160 patients and 466 antimicrobial treatments (235 pre-ASP; 231 post-ASP) were evaluated. Consistent with the primary outcome, antimicrobial appropriateness improved significantly following ASP implementation, with the inappropriateness rate decreasing from 81.7% to 8.7% (p < 0.001), corresponding to an 89.6% reduction in antimicrobial-related problems. Regarding secondary outcomes, overall antimicrobial exposure declined, with total DOT and LOT decreasing by 8.5% and 19.5%, respectively, although median DOT and LOT per patient-day did not differ significantly between periods. The most frequent pharmacist interventions were dose adjustment (38.3%), initial dose selection (35.2%), and infusion duration modification (15.4%), with a 98.1% acceptance rate. Thirty-day mortality decreased from 56.0% to 38.8% (relative risk [RR] 0.699, 95% confidence interval [CI] 0.505-0.968; p = 0.027). In adjusted patient-level analyses, pharmacist intervention was independently associated with lower mortality (adjusted odds ratio [OR] 0.331, 95% CI 0.148-0.743; p = 0.007).

Integration of a clinical pharmacist into a interprofessional audit and feedback process significantly improved antimicrobial appropriateness and reduced antimicrobial-related problems. An associated reduction in 30-day mortality was observed after adjustment for illness severity; however, this finding warrants confirmation in larger prospective studies.