Date of Award

2010

Degree Type

Thesis

Degree Name

Master of Science

Program

Epidemiology and Biostatistics

Supervisor

Dr. Guang Yong Zou

Second Advisor

Dr. Yun-Hee Choi

Abstract

Estimation of simultaneous confidence intervals for multinomial proportions, their differences and ratios is a long-standing problem in the literature. Existing methods suffer either from enforced symmetry and/or conservative coverage. We propose calculating confidence limits using the Wilson method or Jeffrey’s procedure for the multinomial proportions and for ratios of multinomial proportions with critical values obtained from multivariate normal distributions that accounts for correlations among proportions and contrasts. Confidence intervals for the contrasts are then obtained by recovering variance estimates from limits for single proportions. Simulation study shows that proposed methods perform well for a variety of parameter combinations. Data on mutational damage in Saccharomyces cereυisiae is used to illustrate the procedures.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.