Search for dissertations about: "mixed effects models"

Showing result 1 - 5 of 207 swedish dissertations containing the words mixed effects models.

  2. 1. 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

  4. 2. Practical Optimal Experimental Design in Drug Development and Drug Treatment using Nonlinear Mixed Effects Models

    Author : Joakim Nyberg; Andrew C. Hooker; Mats O. Karlsson; Sergei Leonov; Uppsala universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pharmacometrics; optimal design; nonlinear mixed effects models; robust design; optimizing drug development; population models; Pharmacokinetics and Drug Therapy; Farmakokinetik och läkemedelsterapi;

    Abstract : The cost of releasing a new drug on the market has increased rapidly in the last decade. The reasons for this increase vary with the drug, but the need to make correct decisions earlier in the drug development process and to maximize the information gained throughout the process is evident. READ MORE

  5. 3. Pharmacometric Investigations of Prediction Precision and Advances of Models for Composite Scale Data

    Author : Gustaf Wellhagen; Maria C. Kjellsson; Bengt Hamrén; Per Olsson Gisleskog; Uppsala universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; pharmacometrics; modelling; non-linear mixed effects modelling; composite scale data; total score data; total score analysis; precision prediction; bounded integer; bounded integer model; IRT-informed total score analysis; item response theory-informed; mixed models for repeated measures; MMRM; dose-response; dose-response mixed models for repeated measures; DR-MMRM; HbA1c models; fit-for-purpose analysis; clinical trial analysis; Farmaceutisk vetenskap; Pharmaceutical Science;

    Abstract : Clinical trials are needed to evaluate new treatments. In late-stage clinical trials, failures are mostly due to lack of efficacy. Fit-for-purpose analysis methods will likely increase the success rates and advance drug development by providing higher precision to support decisions such as go/no-go, dose selection, or sample size. READ MORE

  6. 4. Statistical modeling and design in forestry : The case of single tree models

    Author : Leakemariam Berhe; Göran Arnoldsson; Göran Broström; Dieter Rasch; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Forest data; Covariance structures; Nonlinear mixed effects models; Tree taper models; Ds-optimal design; Replication-free design.; Statistics; Statistik;

    Abstract : Forest quantification methods have evolved from a simple graphical approach to complex regression models with stochastic structural components. Currently, mixed effects models methodology is receiving attention in the forestry literature. READ MORE

  7. 5. 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