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.