Sökning: "nonlinear mixed-effects models"

Visar resultat 6 - 10 av 27 avhandlingar innehållade orden nonlinear mixed-effects models.

1. 6. Mixed Effects Modeling of Deterministic and Stochastic Dynamical Systems - Methods and Applications in Drug Development

   Författare :Jacob Leander; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; pharmacometrics; pharmacokinetics; mixed effects; drug development; pharmacodynamics; parameter estimation; time-to-event; mathematical modeling; dynamical systems;

   Sammanfattning : Mathematical models based on ordinary differential equations (ODEs) are commonly used for describing the evolution of a system over time. In drug development, pharmacokinetic (PK) and pharmacodynamic (PD) models are used to characterize the exposure and effect of drugs. LÄS MER

3. 7. Development and Evaluation of Nonparametric Mixed Effects Models

   Författare :Paul Baverel; Mats Karlsson; Radojka Savic; Nils Hoem; Uppsala universitet; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

4. 8. Methodology for Handling Missing Data in Nonlinear Mixed Effects Modelling

   Författare :Åsa M. Johansson; Mats O. Karlsson; Andrew C. Hooker; Leon Aarons; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pharmacometrics; population models; censored observations; missing covariates; missing dependent variable; missing data mechanism; missing completely at random MCAR ; missing at random MAR ; missing not at random MNAR ; estimation algorithms; Pharmaceutical Science; Farmaceutisk vetenskap;

   Sammanfattning : To obtain a better understanding of the pharmacokinetic and/or pharmacodynamic characteristics of an investigated treatment, clinical data is often analysed with nonlinear mixed effects modelling. The developed models can be used to design future clinical trials or to guide individualised drug treatment. LÄS MER

5. 9. Statistical modeling and design in forestry : The case of single tree models

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

   Sammanfattning : 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. LÄS MER

7. 10. Pharmacometric Models to Improve Treatment of Tuberculosis

   Författare :Elin M Svensson; Mats O Karlsson; Maria C Kjellsson; Ulrika S H Simonsson; N. L’Ntshotsholé (Shasha) Jumbe; Uppsala universitet; []
   Nyckelord :pharmacokinetics; pharmacodynamics; population approach; nonlinear mixed-effects models; multidrug-resistant tuberculosis; bedaquiline; antiretroviral; drug-drug interactions; time-to-event; albumin; Klinisk farmakologi; Clinical Pharmacology;

   Sammanfattning : Tuberculosis (TB) is the world’s most deadly infectious disease and causes enormous public health problems. The comorbidity with HIV and the rise of multidrug-resistant TB strains impede successful therapy through drug-drug interactions and the lack of efficient second-line treatments. LÄS MER