Cost-effectiveness of a Staphylococcus aureus screening and decolonization program for high-risk orthopedic patients.

We conducted a Markov decision analysis to assess the cost savings associated with a preoperative Staphylococcus aureus screening and decolonization program on 365 hip and knee arthroplasties and 287 spine fusions. A 2-way sensitivity analysis was also used to calculate the needed reduction in surgical site infections to make the program cost saving. If cost of treating an infected hip or knee arthroplasty is equal to the cost of a primary knee arthroplasty, then the screening program needs to result in a 35% reduction in the revision rate, or a relative revision rate of 65% for patients in the screening program, to be cost saving. For spine fusions, the reduction in the revision rate to make the program cost saving is only 10%. Universal Staphylococcus aureus screening and decolonization for hip and knee arthroplasty and spinal fusion patients needs to result in only a modest reduction in the surgical site infection rate to be cost saving.