Cost Effectiveness of Apixaban and Enoxaparin for the Prevention of Venous Thromboembolism After Total Knee Replacement in China

Incremental net monetary benefit of direct oral anticoagulants for the prevention of venous thromboembolism after total knee or hip replacement: A systematic review and meta-analysis

INTRODUCTION

This meta-analysis was conducted to quantitatively pool the incremental net benefit (INB) of using direct oral anticoagulants (DOACs) for the prevention of venous thromboembolism (VTE) in patients undergoing total knee or hip replacements (TKR or THR).

MATERIALS AND METHODS

We performed a comprehensive search in several databases published before June 2021. Studies were included if they were cost-effectiveness analyses reporting cost per quality-adjusted life-year or life-year of DOACs compared to low molecular-weight heparins (LMWHs) or other anticoagulant agents for the prevention of VTE after TKR or THR. Risk of bias was also assessed using the biases in economic studies (ECOBIAS) checklist. Various monetary units were converted to purchasing power parity, adjusted to 2020 US dollars. The INBs were pooled across studies using a random-effects model, stratified by high-income countries (HICs) and low- and middle-income countries (LMICs). Heterogeneity was assessed using the I² statistic.

RESULTS

A total of 49 comparisons (TKR = 25 and THR = 24) from 16 studies was included. In HICs, DOACs were cost-effective compared to LMWHs from the health care system/payer perspective for the prevention of VTE after both TKR and THR with corresponding INBs (95 % CI; I²) of $231.91 ($178.71, $285.11; 0 %) and $254.99 ($159.20, $350.77; 27.79 %), respectively. In LMICs, DOACs were not cost-effective compared to LMWHs for both TKR and THR with the INBs of $94.13 (-$40.21, $228.47; 97.04 %) and $80.55 (-$157.37, $318.47; 99.78 %), respectively. No evidence of small-study effects was identified in any analyses. The cost-effectiveness of using DOACs for TKR and THR in HICs was robust across a series of sensitivity analyses.

CONCLUSIONS

DOACs were cost-effective as compared to LMWHs for VTE prophylaxis following TKR and THR surgeries in HICs. Further studies from LMICs are warranted.

Economic Evaluation of New Oral Anticoagulants in Prevention of Venous Thrombosis Following Joint Replacement Surgery: A Systematic Review

PURPOSE

The main purpose of prescribing oral anticoagulants in patients undergoing total knee and total hip replacement surgery is to prevent venous thromboembolism (VTE). The present study aimed to summarize evidence from economic evaluations regarding new oral anticoagulants (NOACs) used in VTE prophylaxis after joint replacement surgery.

METHODS

To obtain relevant literature on economic evaluations of NOACs used in the prevention of VTE following joint replacement surgery, we searched the Cochrane Library, PubMed, Web of Science, Embase, and Scopus, as well as specialized economic evaluation databases, for articles published from January 2008 to December 2019. Next, 2 reviewers screened the titles and abstracts of studies, extracted data from the full-text articles, and assessed the quality of the methodologies using the Quality of Health Economic Studies checklist.

FINDINGS

Twenty-eight studies of economic evaluations met the inclusion criteria of the research. The quality assessment showed that 20 articles had scores within the range of 75 to 100 (high quality), and 9 studies had scores within the range of 50 to 74 (moderate quality). All of the identified studies had been carried out based on modelling, and 23 studies used decision trees to model acute events after surgery. In addition, 20 studies utilized a Markov model to capture long-term complications of VTE. The results showed that rivaroxaban was more cost-effective than apixaban and dabigatran from a perspective of the health care system in the prevention of VTE after total knee and total hip replacement surgery. In addition, apixaban was associated with a lower risk for bleeding events than other NOACs, making it the most cost-effective NOAC from the perspective of the payer.

IMPLICATIONS

The results suggest that NOACs are cost-effective alternatives to low-molecular-weight heparins. Rivaroxaban and dabigatran were assessed as the most and least cost-effective prophylaxis options, respectively, after joint replacement surgery for the prevention of VTE. It is recommended that future research be conducted on economic evaluations of edoxaban.

Permanent inferior vena cava filters offer greater expected patient utility at lower predicted cost

OBJECTIVE

Retrievable inferior vena cava (IVC) filters were first approved for use in the United States in 2003 to address the long-term complications of migration, thrombosis, fracture, and perforation observed with permanent IVC filter implantation. Although Food and Drug Administration approval of retrievable IVC filters includes permanent implantation, the incidence of complications from long-term implantation appears to be greater than that reported with existing permanent IVC filters. Also, only a small fraction of such retrievable IVC filters are ever retrieved. The purpose of the present study was to determine the threshold retrieval rate at which the use of retrievable IVC filters could be justified.

METHODS

A Markov decision tree was constructed comparing retrievable and permanent IVC filters regarding their effectiveness and cost. A review of the reported data provided outcome probabilities, and the Tufts Medical Center Cost-Effectiveness Analysis Registry was the source of the utility values for the various potential outcomes. Medicare reimbursement rates served as a proxy for costs. A sensitivity analysis was performed for various parameters, primarily to determine the retrieval rate threshold at which the use of retrievable IVC filters would outperform the use of permanent IVC filters.

RESULTS

Base case analysis demonstrated a greater predicted effectiveness for permanent compared with retrievable IVC filter implantation (5.41 quality-adjusted life-years [QALY] vs 5.33 QALY) at a lower cost ($2070 vs $4650). Monte Carlo simulation at 10,000 iterations confirmed the expected utility (5.4 ± 3.0 QALY vs 5.3 ± 3.0 QALY; P = .0002) and cost ($1900 ± $7400 vs $4800 ± 9900; P < .0001) to be statistically superior for permanent IVC filters. A sensitivity analysis for the filter retrieval rate demonstrated that the strategy of using a retrievable IVC filter was never preferable for utility or cost. The superiority of permanent IVC filter placement for effectiveness and cost persisted, regardless of anticipated patient-predicted annual mortality. A two-way sensitivity analysis for both IVC filter removal rate and annual patient mortality confirmed the superiority of permanent IVC filter placement at all levels.

CONCLUSIONS

The predicted effectiveness of permanent IVC filters was greater and the predicted cost lower than those for retrievable IVC filters, regardless of the IVC filter retrieval rate. This interpretation of existing reported data using Markov decision analysis modeling supports the argument that unless the long-term complication rate of retrievable IVC filters can be significantly improved, their use should be abandoned in favor of currently available permanent IVC filters.