Related Experiment Video
Updated: May 1, 2026

Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach
Published on: July 3, 2020
Influence of covariance between random effects in design for nonlinear mixed-effect models with an illustration in
Cyrielle Dumont1, Marylore Chenel, France Mentré
1a Université Paris Diderot, Sorbonne Paris Cité , UMR 738, INSERM, Paris , France.
Abstract:
Nonlinear mixed-effect models are used increasingly during drug development. For design, an alternative to simulations is based on the Fisher information matrix. Its expression was derived using a first-order approach, was then extended to include covariance and implemented into the R function PFIM. The impact of covariance on standard errors, amount of information, and optimal designs was studied. It was also shown how standard errors can be predicted analytically within the framework of rich individual data without the model. The results were illustrated by applying this extension to the design of a pharmacokinetic study of a drug in pediatric development.
More Related Videos
06:52Using Cholesky Decomposition to Explore Individual Differences in Longitudinal Relations between Reading Skills
Published on: September 17, 2019
06:55Inverse Probability of Treatment Weighting Propensity Score using the Military Health System Data Repository and National Death Index
Published on: January 8, 2020
Related Concept Videos
Nonlinear Pharmacokinetics: Causes of Nonlinearity
Nonlinear drug absorption can occur when the process is rate-limited by solubility, carrier-mediated transport systems, or saturation of the presystemic gut wall or hepatic metabolism. For instance, high doses of riboflavin...
Pharmacodynamic Models: Additive and Proportional Drug Effect Model
Nonlinear Pharmacokinetics: Overview
Nonlinearity can arise due to the saturation of plasma protein-binding or...
Analysis of Population Pharmacokinetic Data
Pharmacodynamic Models: Linear Concentration–Effect Model
Parameters Affecting Nonlinear Elimination: Zero-Order Input, First-Order Absorption and Two-Compartment Model
When a drug is administered through a constant intravenous infusion and eliminated via nonlinear pharmacokinetics, it follows zero-order input. For example, oral drugs undergo first-order absorption upon administration and are eliminated through nonlinear pharmacokinetics.
In the case of subcutaneously administered drugs,...