Which statement correctly describes INR?

Which statement correctly describes INR?

• A. A system for reporting blood coagulation or clotting
• B. A test of liver enzyme activity
• C. A measure of electrolyte balance
• D. A marker of kidney function

Answer: (A)

INR is a standardized measure used to report how long blood takes to clot. It’s derived from the prothrombin time and adjusts for variations in lab reagents so results are comparable across different tests. This enables consistent monitoring of anticoagulation therapy, such as warfarin, to keep clotting within a safe therapeutic range. It’s not a test of liver enzyme activity, electrolyte balance, or kidney function—those are addressed by other tests. The normal range in healthy individuals is about 0.8 to 1.2, while therapeutic targets vary by condition and treatment plan.

INR is a standardized measure used to report how long blood takes to clot. It’s derived from the prothrombin time and adjusts for variations in lab reagents so results are comparable across different tests. This enables consistent monitoring of anticoagulation therapy, such as warfarin, to keep clotting within a safe therapeutic range. It’s not a test of liver enzyme activity, electrolyte balance, or kidney function—those are addressed by other tests. The normal range in healthy individuals is about 0.8 to 1.2, while therapeutic targets vary by condition and treatment plan.