Use

Prothrombin time (PT) is used as a screening test to detect a deficiency of one or more of the clotting factors of the extrinsic coagulation system (I, II, V, VII, or X) due to a hereditary or acquired deficiency, liver disease, vitamin K deficiency, or presence of inhibitors. It is also used in monitoring the intensity of oral anticoagulant therapy when combined with international normalized ratio (INR) reporting. PT may be prolonged due to deficiencies of clotting factors, presence of inhibitors, or oral anticoagulation therapy.