COAGULATION CATEGORY

The INR System was established by the World Health Organization and the International Committee on Thrombosis and Hemostasis for monitoring and reporting blood coagulation tests. Under this system, results are standardized using the International Sensitivity Index for the particular test reagent/instrument combination used. The International Normalized Ratio (INR): patient’s PT is compared to the mean PT for a group of normal individuals. The ratio is adjusted for the sensitivity of the laboratory’s thromboplastin determined by the International Sensitivity Index (ISI).

DIC (disseminated intravascular coagulation)	Grade 2 added; Grade 4 revised; Grade 3 value revised
Fibrinogen	Grades 1-4 revised
Fibrinogen for leukemia studies or bone marrow infiltrative/myelophthisic process, if specified in the protocol	Deleted
Partial thromboplastin time (PTT)	No change
Prothrombin time (PT)	Name revised to v3.0 INR (International Normalized Ratio of prothrombin time)
Thrombotic microangiopathy (e.g., thrombotic thrombocytopenic purpura [TTP] or hemolytic uremic syndrome [HUS])	Grade 1 added
Thrombotic microangiopathy For BMT studies, if specified in the protocol	Deleted
Coagulation – Other (Specify, __)	No change