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 Sta phylococcus aureus bacteremia is controversial. Conventional practice dicta tes that all patients receive prolonged courses of intravenous antibiotics. Some clinicians recommend abbreviated therapeutic courses, but an alternat e approach involves prospectively identifying patients for whom abbreviated therapy is appropriate. Objective: To determine the cost-effectiveness of transesophageal echocardi ography (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 wit h S. aureus bacteremia (n = 196) and patients with endocarditis (n = 60); a nd 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 me tastatic infection, immunosuppression, or indwelling prosthetic devices. Time Horizon: Patient lifetime. Perspective: Societal. Interventions: Antibiotic treatment based on TEE results compared with 2- o r 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-co urse strategy were sufficiently similar that the additional cost of empiric al long-course therapy ($1 667 971 per QALY) was higher than that which soc iety usually considers cost-effective. Results of Sensitivity Analyses: In a four-way sensitivity analysis (endoca rditis prevalence, TEE cost, short-course relapse rate, and TEE specificity ), compared with empirical short-course therapy, the TEE strategy results r anged from cost savings to $155 624 per QALY. Conclusion: Within the limitations of existing empirical data, this study s uggests that for patients with clinically uncomplicated catheter-associated 5. aureus bacteremia, the use of TEE to determine therapy duration is a co st-effective alternative to 2- or 4-week empirical therapy.