Falsely elevated international normalized ratio values in patients undergoing anticoagulation therapy: a descriptive evaluation.

Background: Elevated international normalized ratio (INR) values have been linked to bleeding complications; however, elevated INR values are not always physiologic and can be falsely increased. This study describes the rate of falsely elevated INRs and characteristics predictive of falsely elevated INRs.

Methods: This cross-sectional study was conducted among adult patients receiving anticoagulation therapy monitored by a centralized anticoagulation service during January 2000 through December 2004 (n = 29,536).