What is true about INR results in relation to PT tests?

The international normalized ratio (INR) is specifically designed to standardize prothrombin time (PT) results across different laboratories and testing methods. While PT can be influenced by the reagent used, particularly in regards to its sensitivity to different coagulation factors, the INR adjusts for these variations. It does this by using a correction factor called the International Sensitivity Index (ISI), which standardizes the PT results against a reference method. Therefore, the INR provides a consistent measure that allows for comparability regardless of the specific reagents or methods used in different laboratories, further aiding in the management of patients, particularly those on anticoagulation therapy.

The other options do not accurately reflect the nature of INR. For example, INR is not independent of the reagents; it is explicitly designed to account for those differences. In addition, while INR aims for consistency across various patients, individual variations in patient factors still influence the underlying PT results. Lastly, while the INR is particularly important for monitoring anticoagulated patients, it is not limited to them—it can be used more broadly in evaluating coagulation status. Therefore, the true statement about INR results in relation to PT tests emphasizes its purpose as a standardized measure across different testing environments.