Browsing Biostatistics by Title
Now showing items 153-172 of 215
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Rare variant method for identity-by-descent detection in sequence data, and the time to most recent common ancestor given identity-by-descent segment length
(2013-11-14)Identity-by-descent (IBD) is defined as two individuals sharing a haplotype they have both inherited from a common ancestor, where a haplotype is a segment of genetic material found on a single homologue. Existing methods ... -
Recovering Natural History: Modeling Cardiovascular Biomarkers in the Presence of Endogenous Medication Use
In the modern era, cardiovascular biomarkers are often measured in the presence of medication use, whereby the observed value is different than the underlying untreated value for participants on medication. However, for ... -
Recurrent Episode Analyses of Pulmonary Exacerbations in the Infant Study of Inhaled Saline (ISIS) Trial
(2014-02-24)The Infant Study of Inhaled Saline (ISIS) randomized, controlled clinical trial evaluated the use of daily inhaled hypertonic saline treatment for 48 weeks to reduce the rate of pulmonary exacerbations in children of less ... -
Reframing Cox Proportional Hazards Model for Big Data and Neural Networks
In many medical and biomedical applications, we measure the outcome as a “time-to-event” (e.g., disease progression or death). The aim of this dissertation is to propose frameworks for survival analysis and prediction with ... -
Relationship of nighttime arousals and nocturnal cortisol in IBS and normal subjects
(2013-04-17)This study was a secondary analysis of data from a study investigating the association between inflammatory bowel syndrome (IBS) and nocturnal cortisol and catecholamines in a sample of IBS subjects and healthy controls. ... -
Risk factors analysis of longitudinal viral dynamics and immunological responses among HIV-discordant couples
In their 2011 paper “Prevention of HIV-1 infection with Early Antiretroviral Therapy” (Cohen, et al, New England Journal of Medicine, 2011), an interim analysis was performed for the HPTN 052 Study to address both personal ... -
Risk Prediction In Cardiovascular Epidemiology: Considerations for Modeling Composite Endpoints
This thesis reviews construction and evaluation of risk prediction scores in the context of cardiovascular disease. We give an overview of the clinical guidelines that make use of cardiovascular disease risk scores as well ... -
Sampling designs for resource efficient collection of outcome labels for machine-learning, with application to electronic medical records
In leveraging data from large-scale electronic medical record systems for research, an important step is the accurate identification of key clinical outcomes. Some outcomes must be derived or predicted from both structured ... -
Scaled matrix completion and cell deconvolution with NanoString data
This thesis explores two research problems in Chapters 1 and 2. Chapter 1 combines pivotal penalized estimation, with matrix completion, to introduce a new matrix completion problem, where the optimal tuning parameter does ... -
Searching for Predictive Subgroups
Our increased understanding of genomics and related fields has led to: 1) the identification of subtypes of cancer based on various biomarkers and 2) the development of drugs to target specific subtypes. We then use clinical ... -
Searching for Predictive Subgroups with Enhanced Treatment Effect in Clinical Trials using SHAPES
The complexity of the human genome and variability of individual health histories, living environments, and lifestyles have motivated the development of precision medicine with the goal to enable health care providers to ... -
Semiparametric Analysis of an Expanded Cox Proportional Hazards Model with Time-Varying Covariates
Time-varying covariates are often encountered in survival analysis. The Cox proportional hazards model can incorporate time-varying covariates, while the interpretation of regression parameters is less straightforward. We ... -
A Sensitivity Analysis for Clinical Trials with Informatively Censored Survival Endpoints
(2013-02-25)Analyses of clinical trials with time-to-event endpoints typically employ the assumption of non-informative censoring. While this assumption is usually appropriate for end-of-study (EOS) censoring, its applicability to ... -
Sequential safety monitoring using observational data: A comparison of methods appropriate for newly-licensed vaccines in children
(2013-02-25)Sequential safety monitoring of newly-licensed vaccines is a national health priority and is routinely conducted using observational data. However, applying sequential methods in observational settings where the adverse ... -
Sieve Analysis: Statistical Methods for Assessing Genotype-Specific Vaccine Protection in HIV-1 Efficacy Trials with Multivariate and Missing Genotypes
(2012-09-13)The extensive diversity of the human immunodeficiency virus type 1 (HIV-1) poses a major challenge for the design of a successful preventive HIV-1 vaccine. Thus an important component of HIV-1 vaccine development is the ... -
Smoking and CVD in the Multi-Ethnic Study of Atherosclerosis: Functional Form, Mediating Pathways, and Implications of Intensity Reduction
Smoking as an epidemiological exposure can be quantified in terms of duration, intensity, pack-years, recency, and time of life. It is not clear which of these are important for cardiovascular disease, and how they should ... -
Sparse Partial Least Squares Methods and Extensions for Modeling Heart-Healthy Diets
When investigating the link between diet and cardiovascular disease (CVD), nutritional epidemiologists often use unsupervised methods to construct dietary patterns using hundreds of foods. We posit that diet summaries can ... -
Spatial measurement error methods in air pollution epidemiology
Air pollution epidemiology cohort studies often implement a two-stage approach to estimating associations of continuous health outcomes with one or more exposures. An inherent problem in these studies is that the exposures ... -
Statistical Genetic Methods and Applications for Population Structure
Statistical Genetic Methods and Applications for Population Structure. Qian Sophia Zhang. Chair of the Supervisory Committee: Professor Bruce Spencer Weir Biostatistics. -
Statistical Inference for Clustering
In this dissertation, we develop new methods for statistical inference in the context of single- view and multi-view clustering. In the first two chapters, we consider the multi-view data setting, where multiple data sets ...