Since, depending on the examination method and the laboratory, the Quick-value for the measurement of blood coagulation can be different, nowadays another coagulation value is frequently determined additionally: the INR.
The International Normalized Ratio (INR) is also comparable for different measurements in different laboratories and thus more meaningful. The calculation of the INR value is a bit complicated, but for the sake of completeness, the individual quick value is multiplied by an internationally defined index (International Sensitivity Index, ISI) and then by a quick value of normal standardized Shared blood.
An INR value around 1.0 (0.85 to 1.15) is normal. Increased values of 2.0 to 3.5 are found e.g. in anticoagulant treatment with coumarin derivatives (Marcumar & Co).
author:Dr. med. Julia Hofmann