Abstract
OBJECTIVE: To determine the incidence of major hemorrhage among outpatients started on warfarin therapy after the recommendation in 1986 for reduced-intensity anticoagulation therapy was made, and to identify baseline patient characteristics that predict those patients who will have a major hemorrhage.
DESIGN: Retrospective cohort study.
SETTING: A university-affiliated Veterans Affairs Medical Center.
PATIENTS: Five hundred seventy-nine patients who were discharged from the hospital after being started on varfarin therapy.
MEASUREMENTS AND MAIN RESULTS: The primary outcome variable was major hemorrhage. In our cohort of 579 patients, there were 40 first-time major hemorrhages with only one fatal bleed. The cumulative incidence was 7% at 1 year. The average monthly incidence of major hemorrhage was 0.82% during the first 3 months of treatment and decreased to 0.36% thereafter. Three independent predictors of major hemorrhage were identified: a history of alcohol abuse, chronic renal insufficiency, and a previous gastrointestinal bleed. Age, comorbidities, medications known to influence prothrombin levels, and baseline laboratory values were not associated with major hemorrhage.
CONCLUSIONS: The incidence of major hemorrhage in this population of outpatients treated with warfarin was lower than previous estimates of major hemorrhage measured before the recommendation for reduced-intensity anticoagulation therapy was made, but still higher than estimates reported from clinical trials. Alcohol abuse, chronic renal insufficiency, and a previous gastrointestinal bleed were associated with increased risk of major hemorrhage.
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McMahan, D.A., Smith, D.M., Carey, M.A. et al. Risk of major hemorrhage for outpatients treated with warfarin. J GEN INTERN MED 13, 311–316 (1998). https://doi.org/10.1046/j.1525-1497.1998.00096.x
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DOI: https://doi.org/10.1046/j.1525-1497.1998.00096.x