Evaluation of dedicated infectious diseases pharmacists on antimicrobial stewardship teams

Purpose. Patient care improvements and cost savings achieved by a large integrated health system through the implementation of antimicrobial stewardship programs (ASPs) at two hospitals are reported. Methods. A pre-post analysis was conducted to evaluate cost and quality outcomes at the two ASP sites and three similar sites within the same health system not included in the ASP initiative. The utilization of 15 targeted antimicrobials and associated costs at the five sites during designated preimplementation and postimplementation periods were compared; changes in Hospital Standardized Mortality Ratio (HSMR) values for specific infections among Medicare patients were also assessed. Results. In the year after ASP implementation, aggregate direct antimicrobial acquisition costs at the two study sites decreased 17.3% from prior-year levels and increased by 9.1% at the three comparator sites. Significant decreases in the consumption of targeted antimicrobial classes (antipseudomonals, quinolones, and agents active against methicillin-resistant Staphylococcus aureus) were observed at the ASP sites. Among the 2446 ASP interventions recorded, 72% involved discontinuing or narrowing the use of broad-spectrum antimicrobials. Although rates of health care-associated Clostridium difficile infection were little changed at both study sites after ASP implementation, HSMR data indicated substantial gains in combating sepsis and C. difficile and respiratory infections. Conclusion. After implementation of ASPs at two study sites, the utilization of all classes of antibiotics decreased and antimicrobial costs per 1000 patient-days decreased. While HSMR values for sepsis (including C. difficile-associated cases) and respiratory infections improved, the rate of C.difficile infections stayed the same.