Study Analyzes Targeted Cost-Saving Method for MRSA and VRE Surveillance in VA Hospitals

BACKGROUND:
Emerging antibiotic-resistant bacteria, including MRSA (methicillin-resistant Staphylococcus aureus) and VRE (vancomycin-resistant enterococcus), are leading causes of infections in hospitalized patients that result in significant costs, morbidity, and mortality. Efforts to decrease these types of infections have included attempts to reduce transmission through active detection and isolation. Many institutions have adopted active surveillance culturing for MRSA (culturing all patients at hospital admission), including VA, which has mandated this practice since 2007. Because this practice is costly, targeted active surveillance (using a prediction rule to identify a group of patients at high risk for MRSA or VRE among general hospital admissions) has been proposed to contain costs while preserving the potential benefits of active surveillance; hospitalization in the past year has been shown to be a potential prediction rule. This prospective study investigated alternative methods for targeted active surveillance among 585 Veterans admitted to the medical and surgical wards of one VA hospital between 8/07 and 10/09 (non-ICU patients only). Investigators identified potential prediction rules from self-reported and electronic medical record (EMR)-documented variables (e.g., demographics and potential risk factors), and performed surveillance cultures for MRSA and VRE within 48 hours of hospital admission. Prediction rules were evaluated for sensitivity, specificity, and the ability to identify and prevent days of exposure to MRSA and VRE.

FINDINGS:

• Antibiotic exposure documented by VA’s EMR in the year prior to admission was the best prediction rule for MRSA and VRE infections, identifying 84% of MRSA exposure risk and 98% of VRE exposure risk, while culturing only 51% of inpatients.
• During the 26-month study period, active surveillance for MRSA on all non-ICU inpatients would cost $86,773. Targeted active surveillance with EMR documentation of antibiotics would cost $45,255, resulting in a 48% savings. Active surveillance for VRE would cost $77,275 compared to $42,468 for targeted active surveillance, resulting in a 45% savings. An overall cost savings of 47% would result if targeted surveillance or both MRSA and VRE were included.
• Overall, 10.4% of the Veterans in this study were MRSA positive and 6.3% were VRE positive.

LIMITATIONS:

• Results may not be applicable to non-VA hospitals with different sociodemographic and disease distributions.
• Using the prediction rule to culture patients resulted in not identifying approximately 16% of MRSA and 2% of VRE carrier patients. The potential impact of not detecting and isolating these patients is unknown.

IMPACT:

• If validated at other VA facilities, this method has the potential to drastically reduce the cost of the MRSA mandate, while providing a high level of patient safety.

AUTHOR/FUNDING INFORMATION:
This study was partly funded by HSR&D (IIR 04-123). Dr. Perencevich is part of HSR&D’s Center for Research in the Implementation of Innovative Strategies in Practice, Iowa City, IA.

Morgan D, Day H, Furuno J, Young A, Johnson J, Bradham D, and Perencevich E. Improving Efficiency in Active Surveillance for Methicillin-Resistant Staphylococcus Aureus (MRSA) or Vancomycin-Resistant Enterococcus (VRE) at Hospital Admission. Infection Control & Hospital Epidemiology December 2010;31(12):1230-35.