A cost analysis of introducing an infectious disease specialist-guided antimicrobial stewardship in an area with relatively low prevalence of antimicrobial resistance

BACKGROUND Antimicrobial stewardship programs have been widely introduced in hospitals as a response to increasing antimicrobial resistance. Although such programs are commonly used, the long-term effects on antimicrobial resistance as well as societal economics are uncertain. METHODS We performed a cost analysis of an antimicrobial stewardship program introduced in Malmö, Sweden in 20 weeks 2013 compared with a corresponding control period in 2012. All direct costs and opportunity costs related to the stewardship intervention were calculated for both periods. Costs during the stewardship period were directly compared to costs in the control period and extrapolated to a yearly cost. Two main analyses were performed, one including only comparable direct costs (analysis one) and one including comparable direct and opportunity costs (analysis two). An extra analysis including all comparable direct costs including costs related to length of hospital stay (analysis three) was performed, but deemed as unrepresentative. RESULTS According to analysis one, the cost per year was SEK 161 990 and in analysis two the cost per year was SEK 5 113. Since the two cohorts were skewed in terms of size and of infection severity as a consequence of the program, and since short-term patient outcomes have been demonstrated to be unchanged by the intervention, the costs pertaining to patient outcomes were not included in the analysis, and we suggest that analysis two provides the most correct cost calculation. In this analysis, the main cost drivers were the physician time and nursing time. A sensitivity analysis of analysis two suggested relatively modest variation under changing assumptions. CONCLUSION The total yearly cost of introducing an infectious disease specialist-guided, audit-based antimicrobial stewardship in a department of internal medicine, including direct costs and opportunity costs, was calculated to be as low as SEK 5 113.