Deep vein thrombosis (DVT) and pulmonary embolism (PE)-together referred to as venous thromboembolism (VTE)-are important causes of disability and death after all types of major surgery, but particularly after major orthopedic surgery.1 Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are associated with venous stasis, trauma of the deep veins, and liberation of procoagulation factors.2 Without thromboprophylaxis, up to half of THA/TKA patients may develop DVT and up to 2%, fatal PE.3 The long-term clinical outcomes after DVT can be complicated by increased mortality risk, recurrent VTE, and post-thrombotic syndrome,4 while PE can lead to the development of chronic thromboembolic pulmonary hypertension.5 All of these conditions are associated with a considerable economic healthcare system and societal burden.1,2,6,7
The articles in this supplement will take a close look at that burden and what to do about it. In the first article,8 Dr Onur Baser discusses the prevalence of VTE after THA and TKA and describes the implications, both clinical and economic, of failure to use thromboprophylaxis according to evidence-based clinical practice guidelines in patients undergoing those procedures. These may involve rehospitalization and increased risk for recurrence. Thus, there may well be long-term economic consequences for patients who are not provided thromboprophylaxis that is both adequate and of sufficient duration following their THA or TKA.
When evidence-based guidelines are adhered to, however, VTE is largely preventable. In the second paper in this supplement,9 I describe the guidelines that currently exist and the kinds of measures that quality organizations and individual institutions are taking to ensure that those guidelines are being followed. Physicians and surgeons may elect not to adhere to established guidelines out of skepticism about the efficacy and/ or safety of thromboprophylaxis, or they may have an inaccurate conception of the actual benefit-risk ratio. Individual institutions can do much to correct such misconceptions and can also provide tools to enable physicians to monitor their patients and to facilitate appropriate administration of thromboprophylaxis. I describe one such initiative in my article.
In the third paper in this supplement,10 Dr William Fisher discusses the anticoagulants available today and takes a look at the new oral agents currently in development. Existing agents are highly efficacious, and their appropriate use would do much to reduce the number of patients with VTE. At the same time, however, they have numerous drawbacks that make them cumbersome to use and difficult to monitor outside the hospital setting. It is likely that the newer agents will be more suitable for outpatient use and will make it easier for physicians to comply with guidelines and to ensure adequate and effective VTE prophylaxis for their patients.
One of these new oral agents, rivaroxaban, a direct Factor Xa inhibitor, has been extensively studied in the RECORD (REgulation of Coagulation in Orthopedic Surgery to Prevent Deep Venous Thrombosis and Pulmonary Embolism) program. In his contribution to this supplement,11 Dr Louis Kwong describes that program and also examines ways in which rivaroxaban may be able to reduce costs, not only by preventing VTE events, but also by eliminating costs associated with drug administration and management.
In the final article in this supplement,12 Dr Edith Nutescu extends Dr Kwong's observations by examining the benefits of all the new oral anticoagulants, including apixaban and dabigatran, in terms of their potential for cost reduction. She enumerates the ways in which features of the new oral anticoagulants can lead to cost savings for the healthcare system, in comparison with current standards of care.
Differences in the costs associated with thrombosis and of thromboprophylaxis have been assessed by numerous pharmacoeconomic methods,13 but no clear consensus exists as to the best approach.14 However, it is important that healthcare physicians and decision makers involved in the management of thrombosis examine the relevant pharmacoeconomic literature.15 This supplement should help put the economic and clinical value of the emerging anticoagulants into perspective.
1. Edelsberg J, Ollendorf D, Oster G. Venous thromboembolism following major orthopedic surgery: review of epidemiology and economics. Am J Health Syst Pharm. 2001;58(suppl 2):S4-S13.
2. Ollendorf DA, Vera-Llonch M, Oster G. Cost of venous thromboembolism following major orthopedic surgery in hospitalized patients. Am J Health Syst Pharm. 2002;59:1750-1754.
3. Geerts WH, Bergqvist D, Pineo GF, et al. Prevention of venous thromboembolism: American College of Chest Physicians evidence-based clinical practice guidelines (8th ed). Chest. 2008;133:381S-453S.
4. Caprini JA, Botteman MF, Stephens JM, et al. Economic burden of long-term complications of deep vein thrombosis after total hip replacement surgery in the United States. Value Health. 2003;6:59-74.
5. Pengo V, Lensing AW, Prins MH, et al. Incidence of chronic thromboembolic pulmonary hypertension after pulmonary embolism. N Engl J Med. 2004;350:2257-2264.
6. Oster G, Ollendorf DA, Vera-Llonch M, Hagiwara M, Berger A, Edelsberg J. Economic consequences of venous thromboembolism following major orthopedic surgery. Ann Pharmacother. 2004;38:377-382.
7. MacDougall DA, Feliu AL, Boccuzzi SJ, Lin J. Economic burden of deep-vein thrombosis, pulmonary embolism, and postthrombotic syndrome. Am J Health Syst Pharm. 2006;63:S5-S15.
8. Baser O. Prevalence and economic burden of venous thromboembolism after total hip arthroplasty or total knee arthroplasty. Am J Manag Care. 2011;17:S6-S8.
9. Merli G. Quality improvement program: advancement of hospital venous thromboembolism-free zones. Am J Manag Care. 2011;17:S9-S14.
10. Fisher WD. New oral anticoagulants and outpatient prophylaxis of venous thromboembolism. Am J Manag Care. 2011;17:S15-S21.
11. Kwong LM. Cost-effectiveness of rivaroxaban after total hip or total knee arthroplasty. Am J Manag Care. 2011;17:S22-S26.
12. Nutescu E. Characteristics of novel anticoagulants and potential economic implications. Am J Manag Care. 2011;17:S27-S32.
13. Oster G, Tuden RL, Colditz GA. A cost-effectiveness analysis of prophylaxis against deep-vein thrombosis in major orthopedic surgery. JAMA. 1987;257:203-208.
14. Sullivan SD, Kahn SR, Davidson BL, Borris L, Bossuyt P, Raskob G. Measuring the outcomes and pharmacoeconomic consequences of venous thromboembolism prophylaxis in major orthopaedic surgery. Pharmacoeconomics. 2003;21:477-496.
15. Hawkins D. Pharmacoeconomics of thrombosis management. Pharmacotherapy. 2004;24:95S-99S.