COST-EFFECTIVENESS OF SCREENING-BASED STRATEGIES TO PREVENT MRSA TRANSMISSION AND INFECTION

Purpose: We created a policy model to evaluate the projected health benefits, costs and cost-effectiveness of active surveillance culture (ASC)-based screening strategies to prevent MRSA colonization and infection. 

Methods: We constructed a Markov microsimulation model for a hypothetical cohort of 100,000 ICU patients admitted to U.S. hospitals. We compared 4 strategies to standard precautions: (1) ASC using chromogenic culture with contact precautions (CP) for MRSA positive patients; (2) ASC using PCR with CP for MRSA positive patients; (3) ASC using chromogenic culture plus selective decolonization; and (4) ASC using PCR plus selective decolonization. We also varied the timing of test result availability by test type (1 and 2 days for PCR; 1, 2, and 3 days for chromogenic culture). For each strategy, both efficacy and compliance of the strategy’s components were considered and our main outcomes were cases of MRSA colonization and infection averted and incremental CE.

Results: For a cohort of 100,000 patients, 18,100 and 4,800 cases of MRSA colonization and infection, respectively, occurred with standard precautions. ASC-PCR with a 1-day turn-around time + selective decolonization prevented the most cases of MRSA colonization (48%) and infection (53%) followed by ASC-chromogenic culture with a 1-day turn-around + selective decolonization. 2-day turnaround times for ASC-PCR and ASC-chromogenic culture with selective decolonization resulted in up to 5% and 7% fewer cases of colonization and infection averted.  ASC-chromogenic culture with 1-day turn-around + selective decolonization was the least expensive strategy, saving ~$31 million compared to standard precautions due to disease burden averted.  ASC-PCR with 1-day turn-around + selective decolonization resulted in incremental CE ratios of $300 per colonization averted and $730 per infection averted.

Conclusion: ASC-PCR with 1-day turn-around + selective decolonization resulted in the greatest number of cases of MRSA colonization and infection averted.  Both ASC-based + decolonization strategies were cost saving compared to standard precautions. Our model provides useful guidance for hospitals who are choosing between multiple available screening-based strategies to prevent MRSA transmission.