Decreased antimicrobial resistance and defined daily doses after implementation of a clinical culture-guided antimicrobial stewardship program in a local hospital

Background: We aimed to report the implementation of an antimicrobial stewardship program (ASP) guided by clinically significant cultures in a hospital to assess its pharmaceutical, microbiological, financial, and outcome effects. Methods: A 3-year cohort study of an antimicrobial restriction policy implementation was performed. The ASP with culture-guided de-escalation of antibiotics was instituted in a local hospital since January 1, 2012. The cost of antimicrobials, defined daily dose (DDD), susceptibility to antimicrobials, and outcome of all admitted patients were calculated and evaluated before and after the ASP implementation. Results: Average monthly length of stay of admitted patients decreased from 7.8 +/- 0.5 days in 2011 to 6.9 +/- 0.3 days in 2013 (p < 0.001). The average monthly cost of antimicrobials decreased 46.9% from US$ 30,146.8 in 2011 to US$ 16,021.3 in 2013 (p < 0.001). Total intravenous antimicrobial DDDs per 100 bed-days of the inpatients were 66.9, 54.1 and 48.4 in 2011, 2012 and 2013, respectively. A total of 18.6 DDDs per 100 bed-days of inpatients ( 27.7%) decreased from 2011 to 2013. By comparing data in 2013 to those in 2011, the ASP reduced antimicrobial resistance of Gram-positive bacteria (p = 0.013), Gram-negative bacteria (p < 0.001), and predominant species (all p < 0.05). The yearly mortality also decreased from 1.3% in 2011 to 1.1% in 2012 and 1.0% in 2013. Conclusions: The ASP with a culture- guided de-escalation of antibiotics successfully reduced length of stay, mortality, the cost of antimicrobials, DDDs, and antimicrobial resistance rate, and that is highly recommended for local hospitals. Copyright (C) 2015, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC.