Pharmacoeconomic analysis of fondaparinux versus enoxaparin for the prevention of thromboembolic events in orthopedic surgery patients.

INTRODUCTION

Fondaparinux is a novel synthetic antithrombotic that has been evaluated for the prevention of venous thromboembolism (VTE). In four large trials in patients who underwent major hip or knee surgery, fondaparinux was found to have a good safety profile and be more effective than enoxaparin. To generate Canadian pharmacoeconomic data for fondaparinux, an internationally developed cohort deterministic model was used to estimate the costs and consequences of prophylaxis with fondaparinux compared with enoxaparin in the Canadian orthopedic surgical setting.

DESIGN AND SETTING

A health economic advisory group was assembled to guide the pharmacoeconomic evaluation. Efficacy and safety data for fondaparinux relative to enoxaparin were abstracted from a meta-analysis of four randomized trials. Canadian cost data to populate the model were obtained from a resource-use survey of four large Canadian hospitals, from the Canadian Institute for Health Information (CIHI), and from the Canadian economic literature. Case-mix information obtained from CIHI was incorporated into the cohort deterministic model, which predicted the number of VTEs and bleeds following prophylaxis with fondaparinux or enoxaparin within 90 days of surgery, and the associated overall cost difference. The stability of the base-case findings was evaluated with sensitivity analyses.

STUDY PERSPECTIVE

Canadian healthcare system perspective.

MAIN OUTCOME MEASURES AND RESULTS

Assuming a case mix of 50,693 major hip or knee surgeries performed in Canada in 1999/2000 (as reported by CIHI), the model predicted that prophylaxis with fondaparinux would avoid an additional 16 symptomatic VTEs per 1000 patients over the first 90 days, with an average cost savings of Can 55 dollars per patient. These findings were stable when key economic and clinical parameters were varied, including bleeding events.

CONCLUSIONS

Our results suggest that in Canada, prophylactic fondaparinux compared with enoxaparin avoids VTEs and is associated with lower costs in patients who undergo major hip or knee surgery.