INR: International Normalized Ratio. The INR serves to
normalize results obtained from different laboratories for the variable
responsiveness of different thromboplastin reagents. Each thromboplastin
is assigned an International Sensitivity Index (ISI) based on comparison
to an international reference thromboplastin from the World Health
Organization. The formula for calculating the INR is:
INR = [patient's results/normal patient average](ISI)
>Unless noted, all values are for adults. >All laboratory values listed are method dependent
(Methods include: immunoassay, colorimetry, electrophoresis,
HPLC, etc). >Values may vary between laboratories.