Cost-effectiveness of linezolid vs vancomycin in suspected methicillin-resistant Staphylococcus aureus nosocomial pneumonia in Germany.

BACKGROUND: The oxazolidinone antibiotic linezolid has demonstrated efficacy in treating infections caused by methicillin-resistant Staphylococcus aureus (MRSA). In a retrospective analysis of two prospective randomized clinical trials in patients with nosocomial pneumonia (NP), initial therapy with linezolid produced significantly better clinical cure and survival rates than vancomycin in the subset of patients with documented MRSA infection. This study was designed to evaluate the economic impact of these clinical outcomes from the perspective of the German health care system to determine the use of these regimens in the light of limited resources and rising costs.

METHODS: A decision-analytic model using clinical trial data was developed to examine the costs and outcomes of treatment with linezolid or vancomycin in hospitalized patients with NP caused by suspected MRSA. The model followed an average patient from initiation of empiric treatment until treatment success, death, or second-line treatment failure. Local treatment patterns and resource use were obtained from a Delphi panel. Costs were taken from published sources. Outcomes included total cost per patient, cost per additional cure, cost per death avoided, and cost per life-year gained.

RESULTS: The model calculated that linezolid was associated with an 8.7% higher cure rate compared with vancomycin (73.6% vs 64.9%, respectively). Average total costs per episode for linezolid- and vancomycin-treated patients were 12,829 and 12,409, respectively. Death rates were 13.2% lower with linezolid than with vancomycin (20.7% vs 33.9%), resulting in an average of 2.3 life-years gained per linezolid-treated patient in a 65-year-old cohort (14.0 life-years vs 11.7 life-years). With linezolid, incremental costs per death avoided and per patient cured were 3,171 and 4,813, respectively. The base case estimated a similar mean length of stay for both drugs (11.2 vs 10.8 days). One-way sensitivity analyses did not change the overall results.

CONCLUSION: The model estimated a higher clinical cure (+8.7%) and survival (+13.2%) for linezolid compared with vancomycin at an incremental cost of 420 per treatment episode. The cost-benefit profile suggests that linezolid could be considered a cost-effective alternative to vancomycin in the treatment of patients with NP caused by suspected MRSA in Germany.