Journal of General Internal Medicine

, Volume 15, Issue 1, pp 31–37 | Cite as

The cost-effectiveness of different management strategies for patients on chronic warfarin therapy

  • Jennifer Elston Lafata
  • Susan A. Martin
  • Scott Kaatz
  • Richard E. Ward
Original Articles


OBJECTIVE: To examine the cost-effectiveness of moving from usual care to more organized management strategies for patients on chronic warfarin therapy.

DESIGN: Using information available in the scientific literature, supplemented with data from a large health system and, when necessary, expert opinion, we constructed a 5-year Markov model to evaluate the health and economic outcomes associated with each of three different anticoagulation management approaches: usual care, anticoagulation clinic testing with a capillary monitor, and patient self-testing with a capillary monitor.

PATIENTS: Three hypothetical cohorts of patients beginning long-term warfarin therapy were used to generate model results.

MAIN RESULTS: Model results indicated that moving from usual care to anticoagulation clinic testing would result in a total of 1.7 thromboembolic events and 2.0 hemorrhagic events avoided per 100 patients over 5 years. Another 4.0 thromboembolic events and 0.8 hemorrhagic events would be avoided by moving to patient self-testing. When direct medical care costs and those incurred by patients and their caregivers in receiving care were considered, patient self-testing was the most cost-effective alternative, resulting in an overall cost saving.

CONCLUSIONS: Results illustrate the potential health and economic benefits of organized care management approaches and capillary monitors in the management of patients receiving warfarin therapy.

Key Words

anticoagulation management cost-effectiveness analysis decision analytic model warfarin 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Landefeld CS, Beyth RJ. Anticoagulant-related bleeding: clinical epidemiology, prediction, and prevention. Am J Med. 1993;95:315–28.PubMedCrossRefGoogle Scholar
  2. 2.
    Matchar DB, Samsa GP, Cohen SJ. Should we just let the anticoagulation service do it? The conundrum of anticoagulation for atrial fibrillation. J Gen Intern Med. 1996;11:768–70.PubMedCrossRefGoogle Scholar
  3. 3.
    Chiquette E, Amato MG, Bussey HI. Comparison of an anticoagulation clinic with routine medical care. Circulation. 1995;92:1–686. Abstract.Google Scholar
  4. 4.
    Cortelazzo S, Finazzi G, Viero P, Galli M, Remuzzi A, Parenzan L, et al. Thrombotic and hemorrhagic complications in patients with mechanical heart valve prosthesis attending an anticoagulation clinic. Thromb Haemost. 1993;69:316–20.PubMedGoogle Scholar
  5. 5.
    White RH, McKittrick T, Takakuwa J, et al. Management and prognosis of life-threatening bleeding during warfarin therapy. Arch Intern Med. 1996;156:1197–1201.PubMedCrossRefGoogle Scholar
  6. 6.
    Ansell JE, Patel N, Ostrovsky D, Nozzolillo E, Peterson AM, Fish L. Long-term patient self-management of oral anticoagulation. Arch Intern Med. 1995;155:2185–9.PubMedCrossRefGoogle Scholar
  7. 7.
    Hasenkam JM, Knudsen L, Kimose HH, et al. Practicability of patient self-testing or oral anticoagulant therapy by the international normalized ratio (INR) using a portable whole blood monitor. A pilot investigation. Thromb Res. 1997;85:77–82.Google Scholar
  8. 8.
    Bernardo A, Halhuber C. Long-term experience with patient self-management of oral anticoagulation. Ann Hematol. 1996;72:A62. Abstract.Google Scholar
  9. 9.
    Anderson DR, Harrison L, Hirsh J. Evaluation of a portable prothrombin time monitor for home use by patients who require long-term oral anticoagulant therapy. Arch Intern Med. 1993;153:1441–7.PubMedCrossRefGoogle Scholar
  10. 10.
    Fihn SD, McDonell MB, Martin DC, et al. Risk factors for complications of chronic anticoagulation: a multicenter study. Ann Intern Med. 1993;118:511–20.PubMedGoogle Scholar
  11. 11.
    Fihn SD, Callahan CM, Martin DC, et al. The risk for and severity of bleeding complications in elderly patients treated with warfarin. Ann Intern Med. 1996;124:970–9.PubMedGoogle Scholar
  12. 12.
    Gottlieb LK, Salem-Schatz S. Anticoagulation in atrial fibrillation. Does efficacy in clinical trials translate into effectiveness in practice? Arch Intern Med. 1994;154:1945–53.PubMedCrossRefGoogle Scholar
  13. 13.
    The Boston Area Anticoagulation Trial for Atrial Fibrillation Investigators. The effect of low dose warfarin on the risk of stroke in patients with non-rheumatic atrial fibrillation. N Engl J Med. 1990;323:1505–11.CrossRefGoogle Scholar
  14. 14.
    Connolly SJ, Laupacis A, Gent M, Roberts RS, Cairns JA, Joyner C. Canadian atrial fibrillation anticoagulation study. J Am Coll Cardiol. 1991;18:349–55.PubMedCrossRefGoogle Scholar
  15. 15.
    European Atrial Fibrillation Trial Study Group. Secondary prevention in non-rheumatic atrial fibrillation after transient ischemic attack or minor stroke. Lancet. 1993;342:1255–62.Google Scholar
  16. 16.
    The European Atrial Fibrillation Trial Study Group. Optimal oral anticoagulant therapy in patients with non-rheumatic atrial fibrillation and recent cerebral ischemia. N Engl J Med. 1995;333:5–10.CrossRefGoogle Scholar
  17. 17.
    Ezekowitz MD, Bridgers SL, James KE, et al. Warfarin in the prevention of stroke associated with non-rheumatic atrial fibrillation. Veterans Affairs stroke prevention in nonrheumatic atrial fibrillation investigators. N Engl J Med. 1992;327:1406–12.PubMedCrossRefGoogle Scholar
  18. 18.
    Petersen P, Godtfredsen J, Boysen G, Andersen ED, Andersen B. Placebo-controlled, randomised trial of warfarin and aspirin for prevention of thromboembolic complications in chronic atrial fibrillation. The Copenhagen AFASAK study. Lancet. 1989;175–8.Google Scholar
  19. 19.
    Stroke Prevention in Atrial Fibrillation Investigators. Stroke prevention in atrial fibrillation study. Circulation. 1991;84:527–39.Google Scholar
  20. 20.
    Stroke Prevention in Atrial Fibrillation Investigators. Warfarin versus aspirin for prevention of thromboembolism in atrial fibrillation: stroke prevention in atrial fibrillation II study. Lancet. 1994;343:687–91.Google Scholar
  21. 21.
    Palaretti G, Leal N, Cocchen S, et al. Bleeding complications of oral anticoagulant treatment: an inception-cohort, prospective collaborative study (ISCOAT). Lancet. 1996;348:423–8.CrossRefGoogle Scholar
  22. 22.
    van der Meer FJM, Rosendaal FR, Vandenbroucke JP, Briet E. Bleeding complications in oral anticoagulant therapy. An analysis of risk factors. Arch Intern Med. 1993;153:1557–62.PubMedCrossRefGoogle Scholar
  23. 23.
    White RH, McCurdy SA, von Mardensdorff H, Woodruff DE Jr., Leftgoff L. Home prothrombin time monitoring after the initiation of warfarin therapy. Ann Intern Med. 1989;111:730–7.PubMedGoogle Scholar
  24. 24.
    Wilkinson PR, Wolfe CDA, Warburton FG, et al. A long-term follow-up of stroke patients. Stroke. 1997;28:507–12.PubMedGoogle Scholar
  25. 25.
    Bonita R, Solomon N, Broad JB. Prevalence of stroke and strokerelated disability. Estimates from the Auckland Stroke Studies. Stroke. 1997;28:1898–1902.PubMedGoogle Scholar
  26. 26.
    Dorman PJ, Waddell F, Slattery J, Dennis M, Sandercock P. Is the EuroQol a valid measure of health-related quality of life after stroke? Stroke. 1997;28:1876–82.PubMedGoogle Scholar
  27. 27.
    Tennant A, Geddes JML, Fear J, Hillman M, Chamberlain MA. Outcome following stroke. Disabil Rehabil. 1997;19:278–84.PubMedGoogle Scholar
  28. 28.
    Dighe MS, Aparasu RR, Rappaport HM. Factors predicting survival, changes in activity limitations, and disability in a geriatric post-stroke population. Gerontologist. 1997;37:483–9.PubMedGoogle Scholar
  29. 29.
    Naglie G, Detsky AS. Treatment of chronic nonvalvular atrial fibrillation in the elderly: a decision analysis. Med Decis Making. 1992;12:239–49.PubMedCrossRefGoogle Scholar
  30. 30.
    Disch DL, Greenberg ML, Holzberger PT, Malenka DJ, Birkmeyer JD. Managing chronic atrial fibrillation: a Markov decision analysis comparing warfarin, quinidine, and low-dose amiodarone. Ann Intern Med. 1994;120:449–57.PubMedGoogle Scholar
  31. 31.
    Tsevat J, Eckman MH, McNutt RA, Pauker SG. Warfarin for dilated cardiomyopathy: a bloody tough pill to swallow? Med Decis Making. 1989;9:162–9.PubMedCrossRefGoogle Scholar
  32. 32.
    Seto TB, Taira DA, Tsevat J, Manning WJ. Cost-effectiveness of transesophageal echocardiographic-guided cardioversion: a decision analytic model for patients admitted to the hospital with atrial fibrillation. J Am Coll Cardiol. 1997;29:122–30.PubMedCrossRefGoogle Scholar
  33. 33.
    Gage BF, Cardinalli AB, Albers GW, Owens DK. Cost-effectiveness of warfarin and aspirin for prophylaxis of stroke in patients with nonvalvular atrial fibrillation. JAMA. 1995;274:1839–45.PubMedCrossRefGoogle Scholar
  34. 34.
    Sarent R, Wainwright E. Crystal Ball Version 4.0 User Manual. Broomfield, Colo: CG Press; 1996.Google Scholar
  35. 35.
    Gold MR, Siegel JE, Russell LB, Weinstein MC. Cost-effectiveness in Health and Medicine. New York, NY: Oxford University Press, Inc, 1996.Google Scholar
  36. 36.
    Ansell JE, Hamke AK, Holden A, Knapic N. Cost effectiveness of monitoring warfarin therapy using standard versus capillary prothrombin times. Am J Clin Pathol. 1989;91:587–9.PubMedGoogle Scholar
  37. 37.
    US Bureau of the Census, Current Population Reports, Money Income in the United States: 1996 (With Separate Data on Valuation of Noncash Benefits). Washington, DC: US Government Printing Office; 1997:60–197, Table 7.Google Scholar
  38. 38.
    Murphy DJ, Williamson PS, Nease DE Jr. Supportive family members of diabetic adults. Fam Pract Res J. 1994;14:323–31.PubMedGoogle Scholar
  39. 39.
    Mitchell JB, Ballard DJ, Whisnant JP, Ammering CJ, Samsa GP, Matchar DB. What role do neurologists play in determining the costs and outcomes of stroke patients? Stroke. 1996;27:1937–43.PubMedGoogle Scholar
  40. 40.
    Holloway RG, Witter DM, Lawton KB, Lipscomb J, Samsa G. Inpatient costs of specific cerebrovascular events at five academic medical centers. Neurology. 1996;46:860.Google Scholar
  41. 41.
    Health Insurance Association of America. Washington, DC: Source Book of Health Insurance Data, 1996. 854–60:1997.Google Scholar

Copyright information

© Society of General Internal Medicine 2000

Authors and Affiliations

  • Jennifer Elston Lafata
    • 1
  • Susan A. Martin
    • 1
  • Scott Kaatz
    • 1
  • Richard E. Ward
    • 1
  1. 1.Henry Ford Health SystemCenter for Health Services ResearchDetroit

Personalised recommendations