Statistics and Probability Commons^™

Nonparametric Estimation Of Transition Probabilities In Illness-Death Model Based On Ranked Set Sampling, Ying Ma

USF Tampa Graduate Theses and Dissertations

The ranked set sampling (RSS) design is applied widely in agriculture, environmental science, and medical research where the exact measurements of sampling units is costly, but sampling units can be ranked by a correlated concomitant variable. RSS is usually a cost-efficient alternate to simple random sampling (SRS) for selecting more representative samples. This study presents a novel methodology to investigate the nonparametric estimation of transition probabilities in illness-death model using the RSS design. We study the Aalen–Johansen estimator of transition probabilities in illness-death Markov model based on RSS design under random right censoring time and propose nonparametric estimators of the …

Covid-19 And Quantitative Literacy: Focusing On Probability, Michael A. Lewis

Numeracy

The COVID-19 pandemic is arguably the worst crisis the world has faced, so far, in this new century. We haven’t seen a pandemic like this since the 1918 Flu at the beginning of the last century, and, as of this writing, there appears to be no end in sight. What those of us who’re focused on quantitative methods have noticed, in addition to the many people dying, becoming ill, and losing their livelihoods, is the importance of quantitative literacy to an understanding of what’s going on. That’s what this article is about. Specifically, it’s about how the COVID-19 pandemic is …

Exploration Of Factors Associated With Perceptions Of Community Safety Among Youth In Hillsborough County, Florida: A Convergent Parallel Mixed-Methods Approach, Yingwei Yang

USF Tampa Graduate Theses and Dissertations

Introduction: Youth perceived safety is not only linked to crime and violence in a neighborhood but is also associated with health risk behaviors and certain neighborhood characteristics. The purpose of this mixed-methods study was to measure the co-occurring effects of individual and community risk factors by conducting a secondary data analysis using structural equation modeling (SEM) and to explore reasons for youth feeling safe/unsafe in their community using photovoice methodology.

Methods: Syndemic theory/model served as the theoretical framework to guide this mixed-methods study with a convergent parallel design. The quantitative strand (first manuscript) utilized an existing dataset collected from middle …

Effects Of Quantitative Literacy On Healthcare Decision-Making: An Aural Context, Robert G. Root, Sonia Bhala

Numeracy

We propose a relationship between sensory modality, numerical formatting, and performance on a survey simulating healthcare decision-making. We examine the current literature on aural health literacy, and specifically aural literacy coupled with health numeracy. We then create a survey instrument called the Bhala test for this purpose and demonstrate that it is moderately internally consistent and provides results that correlate with the NUMi assessment, a widely accepted measure of health numeracy. The quantitative information provided in the Bhala test has two treatments, percentage and natural frequency formats, in an effort to determine which format is easier for subjects to use …

Angiostrongylus Cantonensis: Epidemiologic Review, Location-Specific Habitat Modelling, And Surveillance In Hillsborough County, Florida, U.S.A., Brad Christian Perich

USF Tampa Graduate Theses and Dissertations

Angiostrongylus cantonensis is a parasitic nematode endemic to tropical and subtropical regions and is the leading cause of human eosinophilic meningitis. The parasite is commonly known as rat lungworm because the primary host in its lifecycle is the rat. A clinical overview of rat lungworm infection is presented, followed by a literature review of rat lungworm epidemiology, risk factors, and surveillance projects. Data collected from previous snail surveys in Florida was considered alongside elevation, population per square kilometer, median household income by zip code territory, and normalized difference vegetation index specific to the geographic coordinates from which the snail samples …

Strategies To Adjust For Response Bias In Clinical Trials: A Simulation Study, Victoria R. Swaidan

USF Tampa Graduate Theses and Dissertations

Background: Response bias can distort treatment effect estimates and inferences in clinical trials. Although prevention, quantification, and adjustments have been developed, current methods are not applicable when subject-level reliability is used as the measure of response bias. Thus, the objective of the current study is to develop, test, and recommend a series of bias correction strategies for use in these cases. Methods: Monte Carlo simulation and logistic regression modeling were used to develop the strategies, examining the collective impact of sample size (N), effect size (ES), reliability distribution, and response style on estimating the treatment effect size in a series …

Analysis Of A Potential A(H7n9) Influenza Pandemic Outbreak In The U.S., Walter A. Silva Sotillo

USF Tampa Graduate Theses and Dissertations

This dissertation presents a collection of manuscripts that describe development of models and model implementation to analyze impact of potential A(H7N9) pandemic influenza outbreak in the U.S. Though this virus is still only animal-to-human transmittable, it has potential to become human-to-human transmittable and trigger a pandemic. This work is motivated by the negative impact on human lives that this virus has already caused in China, and is intended to support public health officials in preparing to protect U.S. population from a potential outbreak of pandemic scale.

An agent-based (AB) simulation model is used to replicate the social dynamics of the …

Geospatial And Negative Binomial Regression Analysis Of Culex Nigripalpus, Culex Erraticus, Coquillettidia Perturbans, And Aedes Vexans Counts And Precipitation And Land Use Land Cover Covariates In Polk County, Florida, Joshua P. Wright

USF Tampa Graduate Theses and Dissertations

Although mosquito monitoring systems in the form of dry-ice bated CDC light traps and sentinel chickens are used by mosquito control personnel in Polk County, Florida, the placement of these are random and do not necessarily reflect prevalent areas of vector mosquito populations. This can result in significant health, economic, and social impacts during disease outbreaks. Of these vector mosquitoes Culex nigripalpus, Culex erraticus, Coquillettidia perturbans, and Aedes vexans are present in Polk County and known to transmit multiple diseases, posing a public health concern. This study seeks to evaluate the effect of Land use Land cover …

Hidden Markov Chain Analysis: Impact Of Misclassification On Effect Of Covariates In Disease Progression And Regression, Haritha Polisetti

USF Tampa Graduate Theses and Dissertations

Most of the chronic diseases have a well-known natural staging system through which the disease progression is interpreted. It is well established that the transition rates from one stage of disease to other stage can be modeled by multi state Markov models. But, it is also well known that the screening systems used to diagnose disease states may subject to error some times. In this study, a simulation study is conducted to illustrate the importance of addressing for misclassification in multi-state Markov models by evaluating and comparing the estimates for the disease progression Markov model with misclassification opposed to disease …

Statistical Analysis And Modeling Health Data: A Longitudinal Study, Bhikhari Prasad Tharu

USF Tampa Graduate Theses and Dissertations

Lung cancer has been considered one of the leading causes of deaths while cancer re- mains the second most common cause of deaths in the USA. Understanding the behavior of a disease over time could yield important information to make decisions about the disease. Statistical models could provide crucial clues and help to make a decision about the dis- ease, budget allocation, evaluation, and implement prevention. Longitudinal trend analysis of the diseases helps to understand long term effects and nature. Cholesterol level is one of the most contributing risk factors for Coronary Heart Disease. Studying cholesterol statistically helps to know …

Trend Analysis And Modeling Of Health And Environmental Data: Joinpoint And Functional Approach, Ram C. Kafle

USF Tampa Graduate Theses and Dissertations

The present study is divided into two parts: the first is on developing the statistical analysis and modeling of mortality (or incidence) trends using Bayesian joinpoint regression and the second is on fitting differential equations from time series data to derive the rate of change of carbon dioxide in the atmosphere.

Joinpoint regression model identifies significant changes in the trends of the incidence, mortality, and survival of a specific disease in a given population. Bayesian approach of joinpoint regression is widely used in modeling statistical data to identify the points in the trend where the significant changes occur. The purpose …

Uncontrolled Hypertension And Associated Factors In Hypertensive Patients At The Primary Healthcare Center Luis H. Moreno, Panama: A Feasibility Study, Roderick Ramon Chen Camano

USF Tampa Graduate Theses and Dissertations

Background: According to the World Health Organization (WHO), hypertension is a major risk factor for cardiovascular disease (CVD), renal impairment, peripheral vascular disease, and blindness. In Panama, a recent study estimated the prevalence of hypertension at 38.5% in the two main provinces of the country, with a rate of uncontrolled hypertension of 47.2%.

Objectives: The aims of this study were to assess the feasibility of the study design and to describe the characteristics of the hypertensive population and the physician's adherence to Panamanian antihypertensive protocols and their relationship with uncontrolled hypertension.

Methods: This is a cross-sectional study of adult hypertensive …

A Monte Carlo Approach To Change Point Detection In A Liver Transplant, Alexia Melissa Makris

USF Tampa Graduate Theses and Dissertations

Patient survival post liver transplant (LT) is important to both the patient and the center's accreditation, but over the years physicians have noticed that distant patients struggle with post LT care. I hypothesized that patient's distance from the transplant center had a detrimental effect on post LT survival. I suspected Hepatitis C (HCV) and Hepatocellular Carcinoma (HCC) patients would deteriorate due to their recurrent disease and there is a need for close monitoring post LT. From the current literature it was not clear if patients' distance from a transplant center affects outcomes post LT. Firozvi et al. (Firozvi AA, 2008) …

Statistical Analysis And Modeling Of Brain Tumor Data: Histology And Regional Effects, Keshav Prasad Pokhrel

USF Tampa Graduate Theses and Dissertations

Comprehensive statistical models for non-normally distributed cancerous tumor sizes are

of prime importance in epidemiological studies, whereas a long term forecasting models

can facilitate in reducing complications and uncertainties of medical progress. The statistical

forecasting models are critical for a better understanding of the disease and supply

appropriate treatments. In addition such a model can be used for the allocations of budgets,

planning, control and evaluations of ongoing efforts of prevention and early detection of

the diseases.

In the present study, we investigate the effects of age, demography, and race on primary

brain tumor sizes using quantile regression methods to …

Decision Aid Models For Resource Sharing Strategies During Global Influenza Pandemics, Alfredo Santana Reynoso

USF Tampa Graduate Theses and Dissertations

Pandemic influenza outbreaks have historically entailed significant societal and economic disruptions. Today, our quality of life is threatened by our inadequate preparedness for the imminent pandemic. The key challenges we are facing stem from a significant uncertainty in virus epidemiology, limited response resources, inadequate international collaboration, and the lack of appropriate science-based decision support tools. The existing literature falls short of comprehensive models for global pandemic spread and mitigation which incorporate the heterogeneity of the world regions and realistic travel networks. In addition, there exist virtually no studies which quantify the impact of resource sharing strategies among multiple countries. This …

Gender Differences In Lung Cancer Treatment And Survival, Margaret Anne Kowski

USF Tampa Graduate Theses and Dissertations

The objectives of this research were to test treatment and survival differences between women and men with lung cancer as there is minimal investigation in the literature. Three research questions were developed with statistical testing for gender differences based on similar cancer type, stage, treatment assignment and survival. Data for 44,863 primary lung cancer cases were collected from eight U.S. state-based cancer registries to investigate the research questions. The lung cancer incidence data included the morphological cell-types of adenocarcinoma (AC); squamous cell carcinoma (SCC); large cell carcinoma (LCC) and small cell carcinoma (SCC). Stage, grade, treatment type, as well as, …

Dna Methylation And Its Association With Prenatal Exposures And Pregnancy Outcomes, Jennifer Straughen

USF Tampa Graduate Theses and Dissertations

Altered DNA methylation may lead to suboptimal fetal programming, increasing the risk of adverse pregnancy outcomes such as small for gestational age (SGA); however, few studies have examined the associations between DNA methylation, prenatal exposures, and fetal outcomes. Cross-sectional data from a larger, ongoing study were used to assess the impact of prenatal smoking on gene specific methylation of umbilical cord blood derived DNA and to investigate the association between gene-specific methylation and risk of SGA. The association between gene-specific DNA methylation and birthweight was also assessed. Maternal and infant covariates were abstracted from medical records, cigarette smoke exposure was …

Evaluation Of Common Inherited Variants In Mitochondrial-Related And Microrna-Related Genes As Novel Risk Factors For Ovarian Cancer, Jennifer Permuth Wey

USF Tampa Graduate Theses and Dissertations

Epithelial ovarian cancer (EOC) is a leading cause of morbidity and mortality among women in the United States, and the etiology is incompletely understood. Common, low penetrant genetic variants such as single nucleotide polymorphisms (SNPs) likely contribute to a significant proportion of EOC. We examined whether SNPs in two understudied yet biologically important types of genes, mitochondrial-related and miRNA-related genes, may contribute to EOC susceptibility using data from a large, homogeneous study population of 1,815 EOC cases and 1,900 controls (frequency-matched on age-group and race/ethnicity) genotyped through stage 1 of an ongoing genome-wide association study. Inter-individual variation in genes involved …

Serum Antibodies To Human Papillomavirus Type 6, 11, 16 And 18 And Their Role In The Natural History Of Hpv Infection In Men, Beibei Lu

USF Tampa Graduate Theses and Dissertations

Our understanding of humoral immune response to human papillomavirus (HPV) infection has been mainly derived from studies in women. Very little is known about humoral immune response to HPV in men. There is also a growing interest in understanding the burden of HPV exposure in the subgroups of the male population, including men who have sex with women (MSW), men who have sex with men (MSM) and men who have sex with both men and women (MSMW). This dissertation was undertaken to understand and characterize humoral immune response, measured by detectable serum antibody IgG, to HPV 6, 11, 16 and …