To the Editor—We appreciate the letter from O’Riordan et alReference O’Riordan, Harrington, Mac Lellen, Ryan and Humphreys ¹ in response to our article on the cost benefit of methicillin-resistant Staphylococcus aureus (MRSA) screening followed by contact precautions in the hospital setting.Reference McKinnell, Bartsch, Lee, Huang and Miller ² We agree that MRSA screening can have an important role as part of infection and control measures. We would like to take the opportunity to highlight 2 important considerations related to cost and benefits of MRSA screening: (1) who is paying for the intervention and who realizes the benefit—that is, the economic perspective, and (2) what we are doing with the MRSA screening data, and particularly what is the resultant intervention efficacy.

Our analysis demonstrated that universal MRSA screening followed by contact precautions would reduce hospital-associated MRSA infections but would result in costs to a hospital. Our findings of increased costs to the hospital remained robust, regardless of number of body sites tested or MRSA identification method. These results are consistent with the literature, including the excellent references presented by O’Riordan et al,Reference O’Riordan, Harrington, Mac Lellen, Ryan and Humphreys ¹ and support the notion that hospital-wide, universal surveillance followed by contact precautions would incur significant costs to a single hospital.

Interestingly, if we look at how universal MRSA screening followed by contact precautions impacts the healthcare system as a whole, the program could result in cost savings.Reference Lee, Bailey and Smith ^{3 ,} Reference Hubben, Bootsma and Luteijn ⁴ The fundamental dilemma is that the costs of hospital-based screening and isolation are borne by the individual hospital performing the screening, but the individual benefits of screening may be reaped only later or by external beneficiaries (eg, other hospitals or non–hospital-based care entities). We suggest that the payment and incentive structure in the US system should be changed to support the expenditures necessary for infection prevention programs to realize both local and regional benefit.

Another key finding from our study was that our results were sensitive to the efficacy of the MRSA intervention. Our intervention efficacy estimates were based on the assumption that MRSA screening results were used to apply contact precautions after a positive test result. We did not model a strategy of preemptive isolation or MRSA decolonization programs.Reference Tubbicke, Hubner, Hubner, Wegner, Kramer and Flessa ⁵ Using a more efficacious intervention would have resulted in our model having lower costs for hospitals and potentially cost saving for the hospital.

We would like to highlight a recent analysis of the Randomized Evaluation of Decolonization versus Universal Clearance to Eliminate (REDUCE) MRSA trial that confirmed that a strategy of using MRSA screening results for targeted decolonization resulted in lower costs compared with screening followed by contact precautions.Reference Huang, Septimus and Avery ⁶ Perhaps most interestingly, the same analysis demonstrated that a strategy of universal decolonization without MRSA screening had the lowest intervention costs and best efficacy.Reference Huang, Septimus and Avery ⁶ The results suggest that MRSA screening may not be required in an intensive care unit setting with universal chlorhexidine bathing. Although the REDUCE MRSA trial is based on intensive care unit costs and benefits, ongoing work is being conducted to explore the impact of decolonization and need for MRSA screening in the broader hospital setting.

Overall, we agree with O’Riordan and colleaguesReference O’Riordan, Harrington, Mac Lellen, Ryan and Humphreys ¹ in their assessment of the literature to support “generally advocating” for MRSA screening as it relates to “infection and control measures.” In particular, understanding the changing epidemiology of MRSA is not fully possible without screening. Depending on the context, available resources, and comparison group, the available data support a benefit to the overall healthcare system for MRSA screening followed by contact precautions. Nevertheless, additional work is needed to understand the role of MRSA screening in the context of additional “infection and control measures,” particularly in the context of universal decolonization where screening may not be required.