Our goals were to determine the incremental cost-effectiveness of linezolid (LIN) compared to vancomycin (VAN) for VAP due to S. aureus and to investigate the cost-effectiveness of broader use of bronchoscopy (FOB) in the management of VAP.
We modeled the cost and efficacy of LIN vs. VAN for treatment of VAP. The primary outcome was the incremental cost-effectiveness of LIN in terms of cost per added quality-adjusted life-year (QALY) gained. A second model investigated the impact of routine FOB in patients suspected of having VAP and its potential to limit costs by decreasing the need for either LIN or VAN. Model estimates were derived from prospective trials of LIN for VAP and from studies describing the costs and outcomes for VAP.
The incremental cost-effectiveness of LIN was calculated as the additional QALYs resulting from therapy with LIN divided by the sum of the incremental costs arising because of use of LIN (e.g., higher direct costs for LIN, costs for in-hospital care of survivors, and post-hospitalization costs). Despite higher acquisition costs, LIN was cost-effective for treatment of VAP. The cost per QALY equaled approximately $30,000. Routine use of FOB improved the cost-effectiveness of LIN (cost per quality-adjusted life-year 3.4% less than baseline case). The model was moderately sensitive to the estimated efficacy of LIN. Nonetheless, with all inputs simultaneously skewed against it, LIN remained a cost-effective option. Based on Monte Carlo simulation, the results of our analysis are robust across a range of model inputs and assumptions (95% CI for cost per QALY: $23,637 to $42,785).CONCLUSIONS: LIN is a cost-effective alternative to VAN. Broader use of FOB may limit costs by decreasing the need for treatment with either LIN or VAN.CLINICAL IMPLICATIONS: Despite higher pharmacy costs, reliance on LIN in VAP may be warranted based on cost-effectiveness. FOB can help contain costs if employed as a tool to limit exposure to antibiotics.
A.F. Shorr, Pharmacia, Grant monies.