Evaluation of assumptions underpinning pharmacometric models

Background: All models are underpinned by assumptions. The validity of any inference drawn from a model depends on the appropriateness and likely impact of the underlying assumptions [1]. However, in the literature surrounding quantitative pharmacology models and pharmacometrics, assumptions inherent to model development and use are not routinely acknowledged, described, or evaluated. This casts doubt […]

Understanding the sensitivity of international normalized ratio (INR) to variations in clotting factor levels

Background: International normalized ratio (INR) is an in vitro blood test designed to measure the clotting time of blood. The INR represents the activity of several clotting factors including fibrinogen, prothrombin (factor II), factor V, factor VII, and factor X. As a global measure of coagulation, the INR is unable to delineate the contributions of […]