Clinical Outcomes from a Community Antimicrobial Stewardship Program with Limited Resources

  Background: Antimicrobial resistance continues to increase, which parallels changes in antimicrobial use.  Given the impact of multi-drug resistant pathogens, appropriate use of antimicrobial agents has become a focus of patient safety.  In June, 2009, an Antimicrobial Stewardship Program (ASP) was developed at St. Joseph Mercy Health System, Ann Arbor, a 535 bed academic community center.  There is limited data on the development and outcomes from ASP in the community setting.  We present clinical outcomes from the first year of our program.

Objective: To decrease the incidence of Clostridium difficile infection (CDI), mortality, and inappropriate antimicrobial use and expenditures.

Methods: The ASP team consisted of two Infectious Diseases (ID) physicians (.3 FTE total), and three Intensive Care Unit pharmacists.  The team prospectively audited the new starts and weekly use of 8 ASP antibiotics (aztreonam, caspofungin, daptomycin, ertapenem, linezolid, meropenem, tigecycline, voriconazole).  Using administrative data, clinical outcomes from first year of the program, such as death within 30 days of hospitalization and incidence of CDI, were compared to outcomes from a similar period prior to the program

Results: 518 antibacterial or antifungal requests were reviewed in 344 patients during the first year.  Of these requests, (322) 62% were considered appropriate, (84) 16% required de-escalation to a narrow spectrum antibiotic, (53) 10% were denied, (27) 5% required an ID consultation.   On multivariate analysis, the intervention period was associated with about a 40% decreased odds of death at 30 days (OR = .59 (.37 - .94)) and about a 50% reduction in the odds of developing CDI (OR = .52 (.29 - .91)).  The antibiotic cost per patient day decreased by 17% in the year following the implementation of the ASP.  The antimicrobial budget decreased by 15% resulting in a savings of $228,911.  

Conclusions: Implementation of the ASP was associated with a reduction in CDI and a decrease in death at 30 days after admission.  The ASP has had a beneficial impact on antimicrobial utilization and costs.  Community ASP can be successful without the expertise of an Infectious Diseases pharmacist.   However, dedicated resources (pharmacy and ID physician FTE time) are critical for the continued success of our ASP.