Impact of monitoring surgical prophylactic antibiotics and a computerized decision support system on antimicrobial use and antimicrobial resistance.

•Monitoring of surgical prophylactic antibiotics and a computerized decision support system for antibiotics prescription were implemented sequentially.•We examined the effects of 2 interventions on antimicrobial use, resistance rates of major nosocomial pathogens, and cost of antibiotics.•Previously increasing trends of antimicrobial use density have been reversed or decreased in slope after interventions.•Trends of the resistance rates of some major pathogens have been reversed or decreased in slope.•Monitoring of surgical prophylactic antibiotics and implementation of a computerized decision support system can be effective measures for antimicrobial stewardship.