Impact of Antimicrobial Stewardship Program (ASP) on Outcomes in Patients with Acute Bacterial Skin and Skin Structure Infections (ABSSSIs) in an Acute-Tertiary Care Hospital

INTRODUCTION: Acute bacterial skin and skin structure infections (ABSSSIs) are among the most common infections treated in hospitals, but to date, there has been little information with regards to the implementation of Antimicrobial Stewardship Programs (ASPs) for patients with ABSSSIs. Hence, we aim to evaluate the impact of ASPs on the following outcomes in patients with ABSSSIs: duration of therapy and hospital stay, 14-day reinfection, infection-related readmissions and mortality. METHODS: A retrospective review of the ASP database was conducted, focusing on selected outcomes (as above) among all patients in whom the institution’s ASP recommended a change in antibiotic regimen—de-escalation of the antibiotic based on culture results; discontinuation of the antibiotic; narrowing of the empirical coverage; and intravenous-to-oral (i.v.-to-p.o.) switch between September 2009 and December 2012. Data were expressed as mean ± standard deviation for continuous variables, and unpaired Student’s t test was performed to determine intergroup differences between mean values. For categorical variables, data were presented as number and percentage and analyzed using the χ (2) test or Fisher’s exact test, as appropriate. RESULTS: ASP recommended 407 interventions with an overall acceptance rate of 66.8%. ASP interventions significantly reduced median duration of therapy by 2 [from a median (interquartile range, IQR) of 8 (6–12) days to 6 (4–9) days] and median length of stay by 5 days [from median (IQR) of 12 (5–32) days to 7 (3–18) days]. This led to an estimated total cost avoidance of USD 0.7 million. There were no significant differences in the 14-day reinfection, infection-related readmission and mortality rates between patients whose physicians accepted and those who rejected ASP interventions. CONCLUSION: Interventions recommended by the ASP in Singapore General Hospital were safe and associated with a significant reduction in duration of therapy and hospital stay. The results of our study have affirmed the role of ASP in optimizing the care of patients with ABSSSI.