Prothombin Time (PT) of a patient is 26, Control PT is 13 seconds and Sensitivity index is 1.41. What will be the INR of this patient?

The INR calculation has become a standard method for monitoring the PT values. It is calculated as = (patient prothrombin time/mean prothrombin time)ISI. Patient prothrombin time = 26 Mean prothrombin time = 13 ISI (International Sensitivity Index) = 1.41 INR = (26/13)1.41 Ref: Laboratory Hematology Practice By Kandice Kottke-Marchant, Bruce Davis, Page 424; Goodman and Gilman's The Pharmacological Basis of Therapeutics, 11th Edition, Page 1479; Physician Assistant's Clinical Companion By Springhouse, Pages 89-91