Impact of an Antimicrobial Stewardship Program on Unnecessary Double Anaerobic Coverage Prescription

BACKGROUND: Co-administration of two or more antimicrobials with anti-anaerobic activity is not recommended except in certain circumstances. We therefore conducted an intervention to reduce unnecessary double anaerobic coverage (DAC) prescription. MATERIALS AND METHODS: The intervention consisted of education using an institutional intranet and prospective audits and feedback provided through collaboration between a pharmacist and an infectious diseases physician in Seoul National University Bundang Hospital, a tertiary hospital in Seongnam, Republic of Korea, in 2013. The study period was 1 year which contained 6 months of pre-intervention period and 6 months of intervention period. To estimate the overall effect of the intervention, we compared the monthly number of patients receiving unnecessary DAC for more than 3 days and the proportion of patients receiving unnecessary DAC for more than 3 days among all patients receiving DAC. RESULTS: The average monthly number of patients receiving unnecessary DAC for more than 3 days after screening decreased by 73.9% in the intervention period from 26.8 to 7.0. Wilcoxon rank sum test revealed there was a significant statistical difference in the monthly number of patients receiving unnecessary DAC for more than 3 days (P = 0.005). The proportion of patients receiving unnecessary DAC for more than 3 days after screening among all patients identified as receiving necessary or unnecessary DAC also decreased by 67.8% in the intervention period from 42.3% to 13.6% (P < 0.001). CONCLUSION: The multidisciplinary antimicrobial stewardship program with combined methods reduced unnecessary DAC prescription successfully.