Sökning: "categorical data"

Visar resultat 6 - 10 av 55 avhandlingar innehållade orden categorical data.

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

   Författare :Maria C. Kjellsson; Mats O. Karlsson; Siv Jönsson; Gordon Graham; Uppsala universitet; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

3. 7. Some properties of measures of disagreement and disorder in paired ordinal data

   Författare :Hans Högberg; Elisabeth Svensson; Sture Holm; Örebro universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; agreement; augmented ranks; categorical data; disorder; jackknife; paired ordinal data; rating scales; sample size; sampling distribution; simulation; U-statistics; variance; SOCIAL SCIENCES; SAMHÄLLSVETENSKAP; Statistics; Statistik; Statistics; Statistik;

   Sammanfattning : The measures studied in this thesis were a measure of disorder, D, and a measure of the individual part of the disagreement, the measure of relative rank variance, RV, proposed by Svensson in 1993. The measure of disorder is a useful measure of order consistency in paired assessments of scales with a different number of possible values. LÄS MER

4. 8. Nonparametric tests for comparing two treatments by using ordinal data

   Författare :Helen Wahlström; Elisabeth Svensson; Jan Lanke; Sture Holm; Örebro universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Statistik; change; clinical trial; Monte Carlo; ordered categorical data; paired data; permutation test; Pitman efficiency; power; stratification; ties; visual analogue scale; Wilcoxon-Mann-Whitney statistic; statistik; Statistics; Statistik; Statistics; Statistik;

   Sammanfattning : This thesis concerns four nonparametric tests for comparing two treatments in a randomized controlled clinical trial when the main response variable generates discrete or continuous ordinal data and measurements are made at baseline and follow-up. In the Wilcoxon-Mann-Whitney test (WMW) the baseline values are not taken into account at all, but in the other three tests both baseline and follow-up values are used. LÄS MER

5. 9. Pharmacometric Methods and Novel Models for Discrete Data

   Författare :Elodie L Plan; Mats O Karlsson; Laura Sargentini-Maier; Armel Stockis; Christian Laveille; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pharmacometrics; pharmacodynamics; disease progression; modelling; discrete data; count; ordered categorical; repeated time-to-event; RTTCE; RCEpT; NONMEM; FOCE; LAPLACE; SAEM; AGQ; pain scores; epilepsy seizures; gastroesophageal symptoms; statistical power; simulations; diagnostics; PHARMACY; FARMACI; Pharmacokinetics and Drug Therapy; Farmakokinetik och läkemedelsterapi;

   Sammanfattning : Pharmacodynamic processes and disease progression are increasingly characterized with pharmacometric models. However, modelling options for discrete-type responses remain limited, although these response variables are commonly encountered clinical endpoints. Types of data defined as discrete data are generally ordinal, e.g. LÄS MER

7. 10. Statistical analysis of gene expression data

   Författare :Erik Kristiansson; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; gene expression; DNA microarrays; linear models; empirical Bayes; quality control; gene regulation; categorical data analysis; logistic regression; heavy metal stress; ecotoxicology; gene expression;

   Sammanfattning : Microarray technology has become one of the most important tools for genome-wide mRNA measurements. The technique has been successfully applied to many areas in modern biology including cancer research, identification of drug targets, and categorization of genes involved in the cell cycle. LÄS MER