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Is warfarin underused in the treatment of elderly persons with atrial fibrillation? Arch Intern Med 1997 Feb 24;157(4):441-5

Date

02/24/1997

Pubmed ID

9046896

DOI

10.1001/archinte.157.4.441

Scopus ID

2-s2.0-0031053980 (requires institutional sign-in at Scopus site)   110 Citations

Abstract

BACKGROUND: Several randomized clinical trials have shown that among patients with atrial fibrillation, warfarin sodium use protects against stroke. Recently, experts have voiced concern about possible underuse of warfarin by practicing physicians. Few studies, however, have quantitated the amount of warfarin underuse.

METHODS: We randomly sampled 65 Medicare beneficiaries discharged alive from each of 5 small Pennsylvania hospitals between July 1, 1993, and June 30, 1994, with a discharge diagnosis code for atrial fibrillation. Trained abstractors verified that atrial fibrillation was present at some time during the hospitalization, determined the presence of contraindications to anticoagulation, and identified warfarin or aspirin use at discharge for each patient. An internist used implicit criteria to identify the reason for warfarin nonuse in patients who had none of the explicit contraindications to warfarin and did not receive it.

RESULTS: Of 322 charts reviewed, 48 patients were not in atrial fibrillation during the hospitalization, 79 had contraindications to warfarin use, 21 either died or were transferred to another hospital, and 2 were admitted with a complication of warfarin. Of the 172 remaining patients, 76 (44%) underwent anticoagulation. On implicit review of the 96 patients who did not undergo anticoagulation, the internist judged that warfarin would not have been appropriate in 54. After excluding those patients, 76 (64%) of the remaining 118 patients underwent anticoagulation. Patients not receiving warfarin were slightly older (81.6 vs 78.3 years old), but this was not statistically significant after stratifying by hospital. Rates of warfarin use at the 5 hospitals varied widely (32%, 57%, 79%, 82%, 94%; P < .001, chi2 with 4 df). Patients with newly diagnosed atrial fibrillation were not more likely to undergo anticoagulation, nor were patients treated by internal medicine or cardiology specialists.

CONCLUSIONS: There may be significant warfarin underuse in some hospitals. Overall, approximately one third of patients with atrial fibrillation for whom it appeared appropriate were not anticoagulated with warfarin. Although the fact that data were not available to or were missed by our review surely justifies some of the underuse, one should recall that even a small amount of underuse may affect a large number of people with this common condition.

Author List

Whittle J, Wickenheiser L, Venditti LN

Author

Jeffrey Whittle MD Professor in the Medicine department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Aged
Aged, 80 and over
Anticoagulants
Atrial Fibrillation
Drug Utilization
Female
Humans
Male
Thrombosis
Warfarin