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Browsing Biostatistics by Title
Now showing items 17-36 of 215
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Adaptive designs in the time to event setting: The potential for benefit and risk
Group sequential designs (GSDs) have been the standard sequential approach to maintain scientific, ethical, and efficiency goals in any confirmatory Phase III studies. Over the past two decades, adaptive extensions to group ... -
Adaptive Randomization Ratios in Multi-arm Clinical Trials
Ethics and economics are two of many motivations for streamlining the process of discovering new therapies for the treatment of human disease. Population ethics and economics dictate that any true benefit be demonstrated ... -
Adaptive Statistical Inference Procedures for Multigroup Data and Phylogenetic Tree Inferences
Multigroup data is a common data type in fields such as biology, the environmental sciences and the social sciences. This dissertation focuses on developing new statistical methodologies for multigroup data analysis. When ... -
Additive hazards regression with incomplete covariate data
(1997)This dissertation addresses two incomplete covariate data problems in the additive hazards (AH) regression model for failure time data. Both are examples of two-phase designs where some covariate is measured only on a ... -
Addressing Lagged Effects and Interval Censoring in the Stepped Wedge Design of Cluster Randomized Clinical Trials
(2014-02-24)The stepped wedge design (SWD) of cluster-randomized trials has been growing in popularity and is increasingly being used to efficiently evaluate the rollout of interventions in a community setting. The design is especially ... -
Adjusting for Misclassified Outcomes in a Multistate Model
(2013-07-25)In this dissertation, we present a new model that accounts for time-dependent sensitivity in multivariate outcome survival models. Our problem was motivated by an interest in estimating baseline risk and associated covariates ... -
Advances in Model-agnostic Approaches to Statistical Inference
This dissertation focuses broadly on contributing to understanding the impact of incorrect modeling assumptions on analyses and arguing for the use of methods for statistical inference that are valid under weaker conditions ... -
An Empirical Study of Convergence Rates and Resampling-based Confidence Interval Methods For Step Threshold Linear Regression Models
This thesis studies the convergence rates of maximum likelihood estimators and coverage probabilities of resampling-based confidence intervals of parameters in step threshold linear regression models through Monte Carlo ... -
An Evaluation of Flexible Summary Measures for the Comparison of Binary Outcomes in Non-Inferiority Trials
In clinical trials, the comparison of binary outcomes between two independent treatment groups is most commonly measured by either relative or absolute differences between outcome rates. In the setting of a non-inferiority ... -
Analysis of biased sampling designs using longitudinal data
With increasing availability of prospective cohort studies, registry data, and electronic health records, numerous secondary investigations are being conducted using data that were originally collected for a different ... -
Analysis of binary longitudinal data with dropout and death
(2002)Dropout (attrition) is a common challenge in analysis of longitudinal data. Additionally, data records may be truncated due to the death of study participants. Response data missing due to death are often modeled by the ... -
Analysis of Bivariate Censored Longitudinal Data: A Case Study
Laboratory measurements that are below the limit of detection (LOD) are common in continuous longitudinal data in the biomedical sciences. The presence of these left-censored values, or non-detects (NDs), complicates the ... -
Analysis of Infectious Disease Incidence and Complex Survey Data in Space and Time
Immunization is one of the most cost-effective health interventions for preventing infectious diseases. Despite the tremendous advances in global immunization coverage in the past few decades, challenges remain in many ... -
Approaches for Developing Treatment Rules
The availability of scientific knowledge and the strength of supporting statistical evidence for efficacy of available treatments varies considerably across clinical settings. Nonetheless, the goal of clinicians remains ... -
Aspects of matching and power in group randomized trials
(2001)A group randomized trial is an experiment in which groups, such as communities, schools or workplaces, are randomized to receive treatment or act as controls. Frequently, the number of groups is small. Because it is the ... -
Assessing accuracy of a continuous medical diagnostic or screening test in the presence of verification bias
(2000)In studies to assess accuracy of a medical diagnostic or screening test, often definitive disease assessment is too invasive or expensive to be ascertained in all subjects. It makes practical and ethical sense to select a ... -
Assessing measurement error correction for genotype imputation in GWAS
(2013-04-17)Abstract not available -
Assessing the Accuracy of Provider Profiling Methods for Classification
(2012-09-13)Provider profiling as a means to describe and compare performance of health care professionals has gained great momentum in the past decade. The implications of profiling, which can drive provider incentives and guide ... -
Assessing Vaccine Effects in HIV-1 Vaccine Trials: Antigenic Maps, Antigen Selection, and Sieve Analysis
(2014-02-24)The goal of vaccination against infectious disease is a net population effect on the risk of infection and/or disease progression. In HIV-1 vaccine development efforts to date only a single HIV-1 vaccine trial has shown ... -
Assessing Vaccine Effects on Infectiousness in COVID-19 Vaccine Trials
Vaccines have played an important role in the public health response to the COVID-19 pandemic. Clinical trials for several candidate vaccines demonstrated high efficacy at pre- venting severe / symptomatic disease. These ...