What does the INR value mean?

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).