Which of the following laboratory tests is used to evaluate the function of the intrinsic and extrinsic coagulation pathways, and is often used to monitor patients on warfarin therapy?

A Prothrombin time (PT) ✓
B Activated partial thromboplastin time (aPTT)
C Bleeding time
D Thrombin time

Explanation

The prothrombin time (PT) test measures the time it takes for blood to clot via the extrinsic and common coagulation pathways, and is often used to monitor warfarin therapy.

Source

Clinical and Laboratory Standards Institute
Hematology Hematology: Coagulation Disorders Hematology: Coagulation Disorders Medium MEDICAL Confidence: high