Cost-effectiveness of transesophageal echocardiography to determine the duration of therapy for intravascular catheter-associated Staphylococcus aureus bacteremia

Background: The appropriate duration of therapy for catheter-associated Staphylococcus aureus bacteremia is controversial. Conventional practice dictates that all patients receive prolonged courses of intravenous antibiotics. Some clinicians recommend abbreviated therapeutic courses, but an alternate approach involves prospectively identifying patients for whom abbreviated therapy is appropriate. Objective: To determine the cost-effectiveness of transesophageal echocardiography (TEE) in establishing duration of therapy for catheter-associated S aureus bacteremia. Design: Cost-effectiveness analysis. Data Sources: MEDLINE search of literature; clinical data from patients with S. aureus bacteremia (n = 196) and patients with endocarditis (n = 60); and costs obtained from the study institution, regional home health agency, and national estimates of professional and technical fees. Target Population: Patients with catheter-associated S aureus bacteremia on native heart valves without intravenous drug use or clinically apparent metastatic infection, immunosuppression, or indwelling prosthetic devices. Time Horizon: Patient lifetime. Perspective: Societal. Interventions: Antibiotic treatment based on TEE results compared with 2- or 4-week empirical therapy. Outcome Measures: Quality-adjusted life expectancy, costs, and incremental cost-effectiveness ratios. Results of Base-Case Analysis: Compared with empirical short-course therapy, the TEE strategy cost $4938 per quality-adjusted life-year (QALY) gained. The effectiveness of the TEE strategy and the effectiveness of the long-course strategy were sufficiently similar that the additional cost of empirical long-course therapy ($1 667 971 per QALY) was higher than that which society usually considers cost-effective. Results of Sensitivity Analyses: In a four-way sensitivity analysis (endocarditis prevalence, TEE cost, short-course relapse rate, and TEE specificity), compared with empirical short-course therapy, the TEE strategy results ranged from cost savings to $155 624 per QALY. Conclusion: Within the limitations of existing empirical data, this study suggests that for patients with clinically uncomplicated catheter-associated 5. aureus bacteremia, the use of TEE to determine therapy duration is a cost-effective alternative to 2- or 4-week empirical therapy.