Impact of full-time equivalent allocation on the effectiveness of antimicrobial stewardship activities: A multicenter study in Okayama, Japan.

Background: Optimized administration of antimicrobial agents is critical for mitigating the emergence of antimicrobial resistance. This study aimed to elucidate the relationship between antimicrobial stewardship (AS) activities and antimicrobial prescription trends and patterns.

Methods: This retrospective, multicenter, longitudinal study was conducted between April 2014 and March 2023 (9-year fiscal period). A structured, questionnaire survey, regarding institutional infrastructure and environmental parameters, service modalities provided by AS activities, resource allocation and systemic support, and data on the use of broad-spectrum antimicrobial agents, was distributed to co-investigators working at seven hospitals in Okayama, Japan. Full-time equivalent (FTE) allocation for each healthcare facility were calculated and subsequently compared among the hospitals. Temporal variations in the proportional distribution of broad-spectrum antimicrobial agents were statistically evaluated using joinpoint regression analysis.

Results: Two hospitals where pharmacists were exclusively dedicated to AS activities and met the recommended FTE allocation showed a statistically significant reduction in the proportion of broad-spectrum antibiotic administration, with average annual percentage changes of -8.0 % (95 % confidence interval [CI]: -10.5 to -5.8) and -3.1 % (95 % CI: -5.5 to -0.7), respectively. In contrast, two other hospitals with full-time AS members but insufficient FTE allocation exhibited inconsistent and statistically nonuniform trends. The remaining three healthcare institutions with poorly resourced AS teams demonstrated no statistically significant trends in their broad-spectrum antimicrobial prescriptions.

Conclusion: Our findings uncovered that hospitals with adequate FTE staffing metrics for AS activities exhibited statistically significant downward trends in the consumption of broad-spectrum antimicrobial agents.