Permanent Inferior Vena Cava Filters Offer Greater Expected Patient Utility at Lower Predicted Cost

Abstract

Retrievable inferior vena cava (IVC) filters were first approved for use in the United States in 2003 to address long-term complications of migration, thrombosis, fracture, and perforation observed with permanent IVC filter implantation. Although approval of retrievable IVC filters includes permanent implantation, the incidence of complications appears to be greater from long-term implantation than from existing permanent IVC filters, and only a small fraction of such retrievable IVC filters are ever retrieved. The purpose of this study was to determine the threshold retrieval rate at which the use of retrievable IVC filters can be justified. A Markov decision tree was constructed comparing retrievable and permanent IVC filters. Review of the literature provided probabilities, and the Tufts Cost-Effectiveness Analysis Registry was the source of the utility values for the various potential outcomes. Medicare reimbursement rates were used as a proxy for costs. Sensitivity analysis was performed for various parameters, primarily to determine the retrieval rate threshold at which use of retrievable IVC filters outperformed permanent IVC filters. Base case analysis demonstrated a greater predicted utility for permanent over retrievable IVC filter implantation (4.68 vs 4.49) at a lower cost ($1080 vs $4160) with a greater net monetary benefit for willingness to pay of $65,000 ($303,000 vs $288,000). Monte Carlo simulation at 10,000 iterations confirmed expected utility (4.65 ± 3.03 vs 4.48 ± 3.02; P < .00001), cost ($1040 ± $4640 vs $4320 ± 8140; P = .00007), and net monetary benefit ($301,000 ± $197,000 vs $287,000 ± $196,000; P < .00001) to be statistically superior. Sensitivity analysis for filter retrieval rate demonstrated that the strategy of use of a retrievable IVC filter is never preferable for any of the three outcomes. The superiority of permanent IVC filter placement for all three outcomes persists regardless of anticipated patient predicted annual mortality. Two-way sensitivity analysis for both IVC filter removal rate and annual mortality confirmed superiority of permanent IVC filter placement at all levels. The predicted utility of permanent over retrievable IVC filters is higher and the predicted cost is lower regardless of rate of ICV filter retrieval. This implies that unless the long-term complication rate of retrievable IVC filters can be significantly improved, regardless of retrieval rate, their use should be abandoned in favor of currently available permanent IVC filters.