Cost-effectiveness of Venous Thromboembolism Prophylaxis After Hospitalization in Patients With Inflammatory Bowel Disease

Abstract

Background: Patients with inflammatory bowel disease (IBD) have a 2- to 3-fold greater risk of venous thromboembolism (VTE) than patients without IBD, with increased risk during hospitalization that persists postdischarge. We determined the cost-effectiveness of postdischarge VTE prophylaxis among hospitalized patients with IBD.

Methods: A decision tree compared inpatient prophylaxis alone vs 4 weeks of postdischarge VTE prophylaxis with 10 mg/day of rivaroxaban. Our primary outcome was quality-adjusted life years (QALYs) over 1 year, and strategies were compared using a willingness to pay of $100,000/QALY from a societal perspective. Costs (in 2020 $USD), incremental cost-effectiveness ratios (ICERs) and number needed to treat (NNT) to prevent 1 VTE and VTE death were calculated. Deterministic 1-way and probabilistic analyses assessed model uncertainty.

Results: Prophylaxis with rivaroxaban resulted in 1.68-higher QALYs per 1000 persons compared with no postdischarge prophylaxis at an incremental cost of $185,778 per QALY. The NNT to prevent a single VTE was 78, whereas the NNT to prevent a single VTE-related death was 3190. One-way sensitivity analyses showed that higher VTE risk >4.5% and decreased cost of rivaroxaban ≤$280 can reduce the ICER to <$100,000/QALY. Probabilistic sensitivity analyses favored prophylaxis in 28.9% of iterations.

Conclusions: Four weeks of postdischarge VTE prophylaxis results in higher QALYs compared with inpatient prophylaxis alone and prevents 1 postdischarge VTE among 78 patients with IBD. Although postdischarge VTE prophylaxis for all patients with IBD is not cost-effective, it should be considered in a case-by-case scenario, considering VTE risk profile, costs, and patient preference.

Keywords: IBD; VTE; cost-effectiveness; prophylaxis.

Figure 1.

Decision tree. Abbreviations: IBD, inflammatory bowel disease; VTE, venous thromboembolism; DVT, deep vein thrombosis; PE, pulmonary embolism; PTS, post-thrombotic syndrome.

Figure 2.

Deterministic 1-way sensitivity analysis to determine if prophylaxis is recommended based on variance of probability of VTE, rivaroxaban prophylaxis vs inpatient prophylaxis alone. Abbreviations: ICER, incremental cost-effectiveness ratio; VTE, venous thromboembolism; WTP, willingness to pay.

Figure 3.

Deterministic 1-way sensitivity analysis to determine if prophylaxis is recommended based on variance of cost of rivaroxaban, rivaroxaban prophylaxis vs inpatient prophylaxis alone. Abbreviations: ICER, incremental cost-effectiveness ratio; VTE, venous thromboembolism; WTP, willingness to pay.

Figure 4.

Tornado diagram showing main drivers (variables and sensitivity ranges) of the incremental cost-effectiveness ratio, rivaroxaban prophylaxis vs inpatient prophylaxis alone. Abbreviations: ICER, incremental cost-effectiveness ratio; VTE, venous thromboembolism; WTP, willingness to pay; EV, expected value; DVT, deep vein thrombosis; PE, pulmonary embolism; PTS, post-thrombotic syndrome.