Search for dissertations about: "linear mixed models"

Showing result 1 - 5 of 153 swedish dissertations containing the words linear mixed models.

  2. 1. On Estimation and Prediction in Linear Mixed Models : A new approach to studying equal BLUEs and BLUPs

    Author : Azadeh Chizarifard; Tatjana von Rosen; Katarzyna Filipiak; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Best linear unbiased estimator; Best linear unbiased predictor; Linear zero function; Matrix equations; statistik; Statistics;

    Abstract : Linear mixed models (LMMs) are widely used to analyze repeated, longitudinal, or clustered data in many disciplines, such as biology, medicine, psychology, sociology, economics, etc. One of the essential components of a linear mixed model is its covariance structure, i.e. READ MORE

  4. 2. Benefits of Non-Linear Mixed Effect Modeling and Optimal Design : Pre-Clinical and Clinical Study Applications

    Author : Charles Ernest II; Andrew Hooker; Mats Karlsson; Bart Ploeger; Uppsala universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pharmacometrics; optimal design; nonlinear mixed effects models; population models; Pharmaceutical Science; Farmaceutisk vetenskap;

    Abstract : Despite the growing promise of pharmaceutical research, inferior experimentation or interpretation of data can inhibit breakthrough molecules from finding their way out of research institutions and reaching patients. This thesis provides evidence that better characterization of pre-clinical and clinical data can be accomplished using non-linear mixed effect modeling (NLMEM) and more effective experiments can be conducted using optimal design (OD). 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. Generalised linear models with clustered data

    Author : Henrik Holmberg; Göran Broström; Kenneth Carling; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Statistics; Statistik; Statistics; statistik;

    Abstract : In situations where a large data set is partitioned into many relativelysmall clusters, and where the members within a cluster have some common unmeasured characteristics, the number of parameters requiring estimation tends to increase with sample size if a fixed effects model is applied. This fact causes the assumptions underlying asymptotic results to be violated. READ MORE

  7. 5. Generalized linear models with clustered data

    Author : Henrik Holmberg; Erling Häggström Lundevaller; Göran Broström; Douglas Bates; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Statistics; statistik;

    Abstract : In situations where a large data set is partitioned into many relatively small groups, and where the members within a group have some common unmeasured characteristics, the number of parameters requiring estimation tends to increase with sample size if a fixed effects model is applied. This fact causes the assumptions underlying asymptotic results to be violated. READ MORE