False incoagulable PT-INR results in oral anticoagulant therapy

Reliability of PT-INR (prothrombin time-international normalized ratio) determination is an essential requirement for the effective and safe management of oral anticoagulant therapy (OAT). Standardization of the pre-analytical and analytical variables (blood collection and sample processing) together with thromboplastin calibration and INR adoption have greatly improved the quality of results.