Evaluating the impact of an Antimicrobial Stewardship Programme on antimicrobial resistance, multidrug resistance, and cost of therapy in a private hospital in Malaysia

The global rise of multidrug-resistant (MDR) organisms driven by inappropriate antimicrobial use has intensified the need for Antimicrobial Stewardship Programmes (ASPs). MDR organisms significantly increased the morbidity and mortality worldwide, which is prevalent in lower-income, middle-income, and developing countries. This study evaluates the impact of ASP implementation on antimicrobial utilization, therapy costs, and resistance trends in a Malaysian tertiary hospital. An ambidirectional cohort study analysed pre- and post-ASP data over one year. Antimicrobial consumption was measured using the Defined Daily Dose (DDD) per 1,000 patient days, and resistance patterns were analyzed. Statistical analyses (Kruskal-Wallis and Student’s t-test) assessed differences in utilization and resistance, while cost analyses determined financial effects. The mean DDD per 1,000 patient days for ASP-targeted antibiotics was significantly decreased by 17% from 161.52 to 134.49 due to the successful implementation of the ASP. Post-ASP observed a wider usage of third-generation cephalosporin, carbapenem, and colistin. Additionally, the annual expenditure for ASP-targeted antibiotics is significantly reduced from RM 30,580.50 to RM 20,590.60 after the implementation of ASP. Significant reductions in the mean MDR bacterial resistance rate were observed for extended-spectrum beta-lactamase Escherichia coli (E. coli) (from 27.48% to 17.85%), methicillin-resistant Staphylococcus aureus (from 22.25% to 15.73%), and MDR Acinetobacter spp. (from 71.46% to 49.34%). ASP implementation is significantly associated with reductions in antimicrobial utilization, therapy costs, and MDR bacterial rates. These findings highlight the effectiveness of ASPs and support their nationwide adoption across Malaysian healthcare institutions to combat antimicrobial resistance (AMR) and enhance clinical outcomes.