Which test measures standardized clotting measurement?

Which test measures standardized clotting measurement?

• A. Prothrombin time
• B. INR
• C. aPTT
• D. Platelet count

Answer: (B)

This item tests how clotting results are made comparable across different labs. The international normalized ratio (INR) is used to standardize prothrombin time results, adjusting for variations in reagents and lab methods. By incorporating the International Sensitivity Index (ISI) and a normal reference value, INR provides a consistent scale to monitor anticoagulation therapy, especially with warfarin. Prothrombin time alone can vary from lab to lab because different reagents affect clotting times. The aPTT measures the intrinsic pathway and is more about heparin-like monitoring rather than standardizing across labs for warfarin. Platelet count is about how many platelets are present, not how long blood takes to clot.

This item tests how clotting results are made comparable across different labs. The international normalized ratio (INR) is used to standardize prothrombin time results, adjusting for variations in reagents and lab methods. By incorporating the International Sensitivity Index (ISI) and a normal reference value, INR provides a consistent scale to monitor anticoagulation therapy, especially with warfarin.

Prothrombin time alone can vary from lab to lab because different reagents affect clotting times. The aPTT measures the intrinsic pathway and is more about heparin-like monitoring rather than standardizing across labs for warfarin. Platelet count is about how many platelets are present, not how long blood takes to clot.