Antimicrobial stewardship in an Internal Medicine ward: effects on antibiotic consumption and on the use of carbapenems.

Assessing the effects of an antimicrobial stewardship program (ASP) implemented in a 78-bed Internal Medicine ward of an Italian mid-sized acute care hospital of 296 beds (26,820 bed days/year in 2015 and 26,653 in 2016). The ASP, implemented in May 2016, included: (a) formulation and dissemination of local guidelines on empiric antibiotic therapy; (b) educational training; and (c) restrictive control on the use of carbapenems. We included in the study all the patients who had received at least one systemic antibiotic as empiric therapy and who were discharged in two comparable time periods (Oct-Nov 2015: period 1 and Oct-Nov 2016: period 2), before and after the implementation of the ASP. Clinical data were collected to compare the two study periods. The percentage of patients treated with antibiotics was significantly lower in period 2 (272/635 = 42.8% vs 238/648 = 36.7%, - 6.1%, p < 0.01). A similar reduction was observed in terms of defined daily doses per 100 bed days (from 49.5 to 46.9; - 5.3%). In period 2, we observed a significant reduction of patients treated with carbapenems (5.7 vs 2.1%, p < 0.05). The length of hospital stay and in-hospital mortality was similar in the two study periods. The implementation of an ASP in our Internal Medicine ward has been associated with a significant reduction of patients treated with antibiotics. The reduction was particularly relevant for carbapenems, antibiotics which should be used only in selected cases. These results have been obtained without increasing length of hospital stay and in-hospital mortality.