Stratifying the risks of oral anticoagulation in patients with liver disease

Chronic liver disease presents a relative contraindication to warfarin therapy, but some patients with liver disease nevertheless require long-term anticoagulation. The goal is to identify which patients with liver disease might safely receive warfarin. Among 102 134 patients who received warfarin from the Veterans Affairs from 2007 to 2008, International Classification of Diseases-Ninth Revision codes identified 1763 patients with chronic liver disease. Specific diagnoses and laboratory values (albumin, aspartate aminotransferase, alanine aminotransferase, creatinine, and cholesterol) were examined to identify risk of adverse outcomes, while controlling for available bleeding risk factors. Outcomes included percent time in therapeutic range, a measure of anticoagulation control, and major hemorrhagic events, by International Classification of Diseases-Ninth Revision codes. Patients with liver disease had lower mean time in therapeutic range (53.5%) when compared with patients without (61.7%; P