Search for dissertations about: "mixed effects model"

Showing result 1 - 5 of 281 swedish dissertations containing the words mixed effects model.

  2. 1. Covariate Model Building in Nonlinear Mixed Effects Models

    Author : Jakob Ribbing; E. Niclas Johnsson; Mats O. Karlsson; Janet Wade; Uppsala universitet; []
    Keywords : Pharmacokinetics Pharmacotherapy; Pharmacokinetics; Pharmacodynamics; Modeling; Covariate selection; Stepwise selection; Covariate analysis; Methodology; Model validation; Model evaluation; Type-2 diabetes; Beta-cell function; Meta analysis; Cross-validation; Least absolute shrinkage and selection operator; Pharmacometrics; ED optimization; Farmakokinetik Farmakoterapi;

    Abstract : Population pharmacokinetic-pharmacodynamic (PK-PD) models can be fitted using nonlinear mixed effects modelling (NONMEM). This is an efficient way of learning about drugs and diseases from data collected in clinical trials. READ MORE

  4. 2. Development and Evaluation of Nonparametric Mixed Effects Models

    Author : Paul Baverel; Mats Karlsson; Radojka Savic; Nils Hoem; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; nonparametric; model; pharmacometrics; pharmacokinetics; pharmacodynamic; imprecision; covariate analysis; parameter distribution; Statistics; computer and systems science; Statistik; data- och systemvetenskap; Pharmaceutical pharmacology; Farmaceutisk farmakologi; Biopharmaceutics; Biofarmaci; Clinical Pharmacology; Klinisk farmakologi; Computer Systems; Datorteknik; Farmakologi; Pharmacology; Statistics; Statistik;

    Abstract : A nonparametric population approach is now accessible to a more comprehensive network of modelers given its recent implementation into the popular NONMEM application, previously limited in scope by standard parametric approaches for the analysis of pharmacokinetic and pharmacodynamic data. The aim of this thesis was to assess the relative merits and downsides of nonparametric models in a nonlinear mixed effects framework in comparison with a set of parametric models developed in NONMEM based on real datasets and when applied to simple experimental settings, and to develop new diagnostic tools adapted to nonparametric models. READ MORE

  5. 3. Contributions to nonlinear mixed-effects modeling

    Author : Jacob Leander; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; nonlinear mixed-effects models; stochastic differential equations; parameter estimation; extended Kalman filter; sensitivity equations; stochastic differential equations;

    Abstract : The topic of this thesis is nonlinear mixed-effects models. A nonlinear mixed-effects model is a hierarchical regression model used to analyze measurements from several individuals simultaneously, which allows sharing of information between similar individuals. READ MORE

  6. 4. Methodological Studies on Models and Methods for Mixed-Effects Categorical Data Analysis

    Author : Maria C. Kjellsson; Mats O. Karlsson; Siv Jönsson; Gordon Graham; Uppsala universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pharmacodynamics; Categorical data; Markov model; Modelling; NONMEM; NLMIXED; Laplace; Gaussian quadrature; Back-Step Method; Proportional odds model; Differential odds model;

    Abstract : Effects of drugs are in clinical trials often measured on categorical scales. These measurements are increasingly being analyzed using mixed-effects logistic regression. However, the experience with such analyzes is limited and only a few models are used. READ MORE

  7. 5. Methods for handling model misspecification in pharmacometric model-based approaches for the analysis of longitudinal clinical trial data

    Author : Estelle Chasseloup; Mats Karlsson; Andrew Hooker; Karl Brendel; Uppsala universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; pharmacometrics; nonlinear mixed-effects models; misspecification; type I error; power; accuracy; placebo; individual model averaging; IMA; likelihood ratio test; LRT; model averaging; covariate selection; mixture models; visual predictive checks; VPC; avatars; digital twins; virtual individual; Farmaceutisk vetenskap; Pharmaceutical Science;

    Abstract : Pharmacometrics model-based analyses proved to be increasingly useful in drug discovery and development. This usefulness was made evident by the formalisation of the model-integrated drug discovery and development framework (MID3). READ MORE