Sökning: "Covariate analysis"

Visar resultat 1 - 5 av 30 avhandlingar innehållade orden Covariate analysis.

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

    Författare :Jakob Ribbing; E. Niclas Johnsson; Mats O. Karlsson; Janet Wade; Uppsala universitet; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  3. 2. Regression Analysis of Censored Data with Applications in Perimetry

    Författare :Anna Lindgren; Matematisk statistik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; censored covariate; L_1 minimization; right-censoring; Quantile regression;

    Sammanfattning : This thesis treats regression analysis when either the dependent or the independent variable is censored. We deal with quantile regression when the dependent variable is censored. LÄS MER

  4. 3. 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

  5. 4. Methodological Studies on Covariate Model Building in Population Pharmacokinetic-Pharmacodynamic Analysis

    Författare :Ulrika Wählby; Thomas Ludden; Uppsala universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pharmaceutical biosciences; Farmaceutisk biovetenskap; Biopharmacy; Biofarmaci; farmakokinetik och läkemedelsterapi; Pharmacokinetics and Drug Therapy;

    Sammanfattning : Population pharmacokinetic (PK) – pharmacodynamic (PD) modelling, using nonlinear mixed effects models, is increasingly being applied to obtain PK-PD information in drug development. Covariate modelling, the establishment of relationships between model parameters and patient characteristics, is undertaken to explain PK-PD variability and facilitate dose adjustment decisions, and is consequently an important objective of population PK-PD. LÄS MER

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

    Författare :Estelle Chasseloup; Mats Karlsson; Andrew Hooker; Karl Brendel; Uppsala universitet; []
    Nyckelord :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;

    Sammanfattning : 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). LÄS MER