Bleeding and Thromboembolism During Anticoagulant Therapy:A Population-Based Study in Rochester, Minnesota
Section snippets
METHODS
Background.—Medical care for the residents of Rochester, Minnesota, is provided by the Mayo Clinic, Olmsted Medical Group, and a small number of independent providers. The Mayo Clinic uses a dossier (or unit record) system wherein all data on a specific patient are contained in a single file. In the community, anticoagulant therapy is monitored in only three laboratories, each of which maintains records of all such tests performed. We used a comprehensive medical diagnostic index to identify
RESULTS
Patient Characteristics and Indications for Anticoagulant Therapy.-During the 28-month study period, 261 patients had incident courses of long-term oral anticoagulant therapy with warfarin, a total of 221 patient-years of warfarin exposure. Of the patients, 52% were male. The median age of the study group was 69 years (range, 6 to 96); 39% of patients were younger than 65 years of age, 30% were 65 to 74 years old, and 31% were 75 years old or older (Table 1). The decision to initiate long-term
DISCUSSION
Warfarin therapy can be initiated only after the risks of thromboembolism related to a patient's underlying condition are weighed against the risks of hemorrhagic complications of such anticoagulant therapy. Our current study is the first to provide data on hemorrhagic and thromboembolic complications of anticoagulant therapy in a population-based cohort. Therefore, our results should apply to most practice settings, because we studied all patients who received warfarin in the community and not
CONCLUSION
The current population-based study of hemorrhagic and thromboembolic episodes in patients receiving warfarin anticoagulation allowed easy and well-monitored medical care and frequent follow-up. Even in this setting, the cumulative risks of major and minor hemorrhage and thromboembolism were substantial and were higher than those reported in clinical trials. The decision to recommend long-term treatment with warfarin must be weighed in light of these findings.
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Cited by (0)
This study was supported in part by Research Grants AR 30582 and HL 46974 from the National Institutes of Health, Public Health Service, by FD-T-000886 from the Food and Drug Administration, and by Mayo Foundation.
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Current address: Prairie Cardiovascular Clinic, Springfield, Illinois.
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Current address: Georgetown University Medical Center, Washington, DC.