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Failure to prescribe warfarin to patients with nonrheumatic atrial fibrillation

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Abstract

OBJECTIVE: To determine how often warfarin was prescribed to patients with nonrheumatic atrial fibrillation in our community in 1992 when randomized trials had demonstrated that warfarin could prevent stroke with little increase in the rate of hemorrhage, and to determine whether warfarin was prescribed less frequently to older patients—the patients at highest risk of stroke but of most concern to physicians in terms of the safety of warfarin.

DESIGN: Cross-sectional study. Appropriateness of warfarin was classified for each patient based on the independent judgments of three physicians applying relevant evidence and guidelines.

SETTING: Two teaching hospitals and five community-based practices.

PATIENTS: Consecutive patients with nonrheumatic atrial fibrillation (n=189).

MEASUREMENTS AND MAIN RESULTS: Warfarin was prescribed to 44 (23%) of the 189 patients. Warfarin was judged appropriate in 98 patients (52%), of whom 36 (37%) were prescribed warfarin. Warfarin was prescribed to 11 (14%) of 76 patients aged 75 years or older with hypertension, diabetes mellitus, or past stroke, the group at highest risk of stroke. In a multivariable logistic regression model controlling for appropriateness of warfarin and other patient characteristics, patients aged 75 years or older were less likely than younger patients to be treated with warfarin (odds ratio 0.25; 95% confidence interval 0.10, 0.65).

CONCLUSIONS: Warfarin was prescribed infrequently to these patients with nonrheumatic atrial fibrillation, especially the older patients and even the patients for whom warfarin was judged appropriate. These findings indicate a substantialopportunity to prevent stroke.

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References

  1. Wolf PA, Abbott RD, Kannel WB. Atrial fibrillation; a major contributor to stroke in the elderly. The Framingham Study. Arch Intern Med. 1987;147:1561–4.

    Article  PubMed  CAS  Google Scholar 

  2. Feinberg WM, Blackshear JL, Laupacis A, Kronmal R, Hart RG. Prevalence, age distribution, and gender of patients with atrial fibrillation. Analysis and implications. Arch Intern Med. 1995;155:469–73.

    Article  PubMed  CAS  Google Scholar 

  3. Chang HJ, Bell JR. Deroo DB, Kirk JW, Wasson JH. Dartmouth Primary Care COOP Project. Physician variation in anticoagulating patients with atrial fibrillation. Arch Intern Med. 1990;150:81–4.

    Article  Google Scholar 

  4. Kutner M, Nixon G, Silverstone F. Physicians’ attitudes toward oral anticoagulants and antiplatelet agents for stroke prevention in elderly patients with atrial fibrillation. Arch Intern Med. 1991;151:1950–3.

    Article  PubMed  CAS  Google Scholar 

  5. Petersen P, Boysen G, Godtfredsen J, Andersen ED, Andersen B. Placebo-controlled, randomised trial of warfarin and aspirin for prevention of thromboembolic complications in chronic atrial fibrillation. Lancet. 1989;1:175–9.

    Article  PubMed  CAS  Google Scholar 

  6. Boston Area Anticoagulation Trial for Atrial Fibrillation Investigators. The effect of low-dose warfarin on the risk of stroke in patients with nonrheumatic atrial fibrillation. N Engl J Med. 1990;323:1505–11.

    Article  Google Scholar 

  7. Stroke Prevention in Atrial Fibrillation Study Group Investigators. Preliminary report of stroke prevention in atrial fibrillation study. N Engl J Med. 1990;322:863–8.

    Google Scholar 

  8. Connolly SJ, Laupacis A, Gent M, Roberts RS, Caims JA, Joyner C. Canadian atrial fibrillation anticoagulation (CAFA) study. J Am Coll Cardiol. 1991;18:349–55.

    Article  PubMed  CAS  Google Scholar 

  9. Ezekowitz MD, Bridgers SL, James KE, et al. Warfarin in the prevention of stroke associated with nonrheumatic atrial fibrillation. N Engl J Med. 1992;327:1406–12.

    Article  PubMed  CAS  Google Scholar 

  10. Atrial Fibrillation Investigators. Risk factors for stroke and efficacy of antithrombotic therapy in atrial fibrillation. Analysis of pooled data from five randomized controlled trials. Arch Intern Med. 1994;154:1449–57.

    Article  Google Scholar 

  11. Singer DE. Randomized trials of warfarin for atrial fibrillation. N Engl J Med. 1992;327:1451–3.

    Article  PubMed  CAS  Google Scholar 

  12. Laupacis A, Albers G, Dunn M, Feinberg W. Antithrombotic therapy in atrial fibrillation. Chest. 1992;102:426S-33S.

    PubMed  CAS  Google Scholar 

  13. Laupacis A, Albers G, Dunn M, Feinberg W. Antithrombotic therapy in atrial fibrillation. Chest. 1995;108:352S-9S.

    PubMed  CAS  Google Scholar 

  14. 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.

    Article  PubMed  CAS  Google Scholar 

  15. Bath PMW, Prasad A, Brown MM, MacGregor GA. Survey of use of anticoagulation in patients with atrial fibrillation. BMJ. 1993;307:1045.

    Article  PubMed  CAS  Google Scholar 

  16. Wennberg JE, Mulley AG Jr., Hanley D, et al. An assessment of prostatectomy for benign urinary tract obstruction. Geographic variations and the evaluation of medical care outcomes. JAMA. 1988;259:3027–30.

    Article  PubMed  CAS  Google Scholar 

  17. Chassin MR, Brook RH, Park RE, et al. Variations in the use of medical and surgical services by the Medicare population. N Engl J Med. 1986;314:285–90.

    Article  PubMed  CAS  Google Scholar 

  18. Anderson FA Jr., Wheeler B, Goldberg RJ, Hosmer DW, Forcier A, Patwardhan NA. Changing clinical practice. Prospective study of the impact of continuing medical education and quality assurance programs on use of prophylaxis for venous thromboembolism. Arch Intern Med. 1994;154:669–77.

    Article  PubMed  Google Scholar 

  19. Goldman L. Changing physicians’ behavior. The pot and the kettle. N Engl J Med. 1990;322:1524–5.

    Article  PubMed  CAS  Google Scholar 

  20. Lomas J, Anderson GM, Domnick-Pierre K, Vayda E, Enkin MW, Hanna WJ. Do practice guidelines guide practice? The effect of a consensus statement on the practice of physicians. N Engl J Med. 1989;321:1306–11.

    Article  PubMed  CAS  Google Scholar 

  21. Lomas J, Enkin M, Anderson GM, Hannah WJ, Vayda E, Singer J. Opinion leaders versus audit and feedback to implement practice guidelines: delivery after previous cesarean section. JAMA. 1991;265:2202–7.

    Article  PubMed  CAS  Google Scholar 

  22. Greco PJ, Eisenberg JM. Changing physicians’ practices. N Engl J Med. 1993;329:1271–4.

    Article  PubMed  CAS  Google Scholar 

  23. Albers GW. Atrial fibrillation and stroke. Three new studies, three remaining questions. Arch Intern Med. 1994;154:1443–8.

    Article  PubMed  CAS  Google Scholar 

  24. Bailar JC, Louis TA, Lavori PW, Polansky M. A classification for biomedical research reports. N Engl J Med. 1984;311:1482–7.

    Article  PubMed  Google Scholar 

  25. Laupacis A. Anticoagulants for atrial fibrillation. Lancet. 1993;342:1251–2.

    Article  PubMed  CAS  Google Scholar 

  26. Landefeld CS, Beyth RJ. Anticoagulant-related bleeding: clinical epidemiology, prediction and prevention. Am J Med. 1993;95:315–28.

    Article  PubMed  CAS  Google Scholar 

  27. McCrory DC, Matchar DB, Samsa G, Sanders LL, Pritchett ELC. Physician attitudes about anticoagulation for nonvalvular atrial fibrillation. Arch Intern Med. 1995;155:277–81.

    Article  PubMed  CAS  Google Scholar 

  28. Fihn SD, McDonell M, Martin D, et al. Risk factors for complications of chronic anticoagulation. A multicenter study. Ann Intern Med. 1993;118:511–20.

    PubMed  CAS  Google Scholar 

  29. Fihn SD, Callahan CM, Martin DC, McDonnell MB, Henikoff JG, White RH. The risk for and severity of bleeding complications in elderly patients treated with warfarin. Ann Intern Med. 1996;124:970–9.

    PubMed  CAS  Google Scholar 

  30. Landefeld CS, Goldman L. Major bleeding in outpatients treated with warfarin: incidence and prediction by factors known at the start of outpatient therapy. Am J Med. 1989;87:144–52.

    PubMed  CAS  Google Scholar 

  31. Landefeld CS, Rosenblatt MW, Goldman L. Bleeding in outpatients treated with warfarin: relation to the prothrombin time and important remediable lesions. Am J Med. 1989;87:153–9.

    Article  PubMed  CAS  Google Scholar 

  32. Stroke Prevention in Atrial Fibrillation Study Group 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 

  33. Lamas GA, Pfeffer MA, Hamm P, et al. Do the results of randomized clinical trials of cardiovascular drugs influence medical practice? N Engl J Med. 1992;327:241–7.

    Article  PubMed  CAS  Google Scholar 

  34. CAST Investigators. Effect of encainide and flecainide on mortality in a randomized trial of arrhythmia suppression after myocardial infarction. N Engl J Med. 1989;321:406–12.

    Article  Google Scholar 

  35. Furberg CD, Psaty BM, Manolio TA, Gardin JM, Smith VE, Rautaharju PM. Prevalence of atrial fibrillation in elderly subjects (the Cardiovascular Health study). Am J Cardiol. 1994;74:236–41.

    Article  PubMed  CAS  Google Scholar 

  36. Flegel KM. Hutchinson TA, Groome PA, Tousignant P. Factors relevant to preventing embolic stroke in patients with non-rheumatic atrial fibrillation. J Clin Epidemiol. 1991;44:551–60.

    Article  PubMed  CAS  Google Scholar 

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Dr. Antani performed this work as a medical student at Case Western Reserve University. Dr. Landefeld is a Senior Research Associate, Health Services Research and Development Service, Department of Veterans Affairs. Dr. Beyth is a Merck/AFAR Fellow in Geriatric Clinical Pharmacology. Dr. Covinsky is an awardee of the Research and Development Core, Claude D. Pepper Older Americans Independence Center, Case Western Reserve University.

Supported by an American College of Physicians’ George Morris Piersol Teaching and Research Scholarship (CSL), a John A. Hartford Foundation/American Federation for Aging Research Geriatric Pharmacology Scholarship (MRA), and by grants from the John A. Hartford Foundation (92307-G and the Case Western Reserve University Geriatric Recruitment Initiative) and the National Institutes of Health (RO1 AG09657-01 and P60 AG10418-03).

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Antani, M.R., Beyth, R.J., Covinsky, K.E. et al. Failure to prescribe warfarin to patients with nonrheumatic atrial fibrillation. J Gen Intern Med 11, 713–720 (1996). https://doi.org/10.1007/BF02598984

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