Using propensity scores to estimate the cost-effectiveness of medical therapies.

The cost-effectiveness ratio is a popular statistic that is used by policy makers to decide which programs are cost-effective in the public health sector. Recently, the net monetary benefit has been proposed as an alternative statistical summary measure to overcome the limitations associated with the cost-effectiveness ratio. Research on using the net monetary benefit to assess the cost-effectiveness of therapies in non-randomized studies has yet to be done. Propensity scores are useful in estimating adjusted effectiveness of programs that have non-randomized or quasi-experimental designs. This article introduces the use of propensity score adjustment in cost-effectiveness analyses to estimate net monetary benefits for non-randomized studies. The uncertainty associated with the net monetary benefit estimate is evaluated using cost-effectiveness acceptability curves. Our method is illustrated by applying it to SEER-Medicare data for muscle invasive bladder cancer to determine the most cost-effective treatment protocol.