Biostatistics Commons^™

Development Of A Metapgs For Accurate Prediction Of Osteoporotic Fracture, Xiangxue Xiao

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction: Early identification of individuals at high-risk for osteoporotic fractures who may benefit from preventive intervention is essential. However, the predictive accuracy of the currently used fracture risk assessment tool remains suboptimal. The first aim of this research is to construct genome-wide polygenic scores for the femoral neck (PGS_FNBMD_idpred) and total body BMD (PGS_TBBMD_idpred) and to estimate their potential in identifying individuals with a high risk of osteoporotic fractures. The second aim is to validate the predictive performance of two previously established PGSs (PGS_FNBMD_idpred and PGS_TBBMD_idpred) in an external cohort …

Polygenic Risk Score Development And Validation For Early Detection And Risk Stratification Of Rheumatoid Arthritis And Osteoarthritis In Postmenopausal Women, Yingke Xu

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction: Around one in four adults worldwide suffer from arthritis. There are more than one hundred different forms of arthritis; the two most common forms of arthritis are rheumatoid arthritis (RA) and osteoarthritis (OA). RA is an autoimmune disease that can cause joint inflammation. Around 1.3 million adults in the US suffer from RA, representing 0.6%–1% of the population. The RA diagnosis in its early stages is difficult since its signs and symptoms are similar to other arthritis. OA is the most common form of arthritis. In the US, around 30.8 million people are affected by this disease. However, OA …

Editorial, Al Asyary

Kesmas

No abstract provided.

Approaches To Detecting And Modeling Over-And Underdispersion In Alternative Count Data Distributions And An Application Of Logistic Regression And Random Forest Modeling To Improve Screening Tools For Tic Disorders In Children, Rebecca C. Wardrop

Theses and Dissertations

This dissertation focuses on theory and application of discrete data methods, particularly approaches to over- and underdispersion relative to the Poisson distribution and an application of random forest and logistic regression modeling. The first chapter derives a score test for over- and underdispersion in the heaped generalized Poisson distribution. Equi-, over-, and underdispersed heaped generalized Poisson and heaped negative binomial data are simulated to evaluate the performance of the score test by comparing the power it achieves to that of Wald and likelihood ratio tests. We find that the score test we derive performs comparably to both the Wald and …

Statistical Methods For Single Cell Sequencing Data Analysis, Fei Qin

Theses and Dissertations

The recent emergence of single cell sequencing (SCS) technology has provided us with single-cell DNA or RNA sequencing (scDNA/RNA-seq) information to investigate cellular evolutionary relationships. Despite many analysis methods have been developed to infer intra-tumor genetic heterogeneity, cluster cellular subclones, detect genetic mutations, and investigate spatially variable (SV) genes, exploring SCS data remains statistically challenging due to its noisy nature.

To identify subclones with scDNA-seq data, many existing studies use an independent statistical model to detect copy number profile in the first step, followed by classical clustering methods for subclone identification in downstream analyses. However, spurious results might be generated …

A Bayesian Spatial Scan Statistic For Normal Data, Laasya Velamakanni

Theses and Dissertations

Scan statistics are useful methods for detecting spatial clustering. While they were initially developed to detect regions with an excess of binomial or Poisson events, spatial scan statistics have been extended to detect hotspots in other types of data including continuous data. They have many applications in different fields such as epidemiology (e.g. detecting disease outbreaks), sociology (e.g. detecting crime hotspots), and environmental health (e.g. detecting high-pollution areas). Spatial scan statistics identify a ‘most likely cluster’ and then use a likelihood ratio test to determine if this cluster is statistically significant. Spatial scan statistics have been extended to the Bayesian …

Statistical Methods For Semi-Competing And Competing Risks Data With Missing Event Types, Ruiqian Wu

Theses & Dissertations

There is a growing interest in modeling multiple event data in biomedical and public health investigations. Competing and semi-competing risks data are two special types of multiple event data. Statistical modeling of semi-competing risks data involves an intermediate event and a terminal event and emphasizes the investigation of the effect of the intermediate event on the terminal event. The investigation of the semi-competing risks data model not only enables us to determine if a disease episode is associated with mortality but also provides a toolkit for predicting death if the episode occurred at a particular time. Meanwhile, the interpretation of …

Unraveling The Neural Basis Of Emotions: Advancing Understanding With Ecologically Valid Paradigms And High-Resolution Intracranial Eeg, Tiankang Xie

Dartmouth College Ph.D Dissertations

Background

Emotion arises from integrating information about the external world with memories of past experiences, current homeostatic states, and future goals. They play a vital role in regulating our thoughts, feelings and behaviors, significantly impacting our mental health. Thus, it is important to understand the neurobiological mechanisms that give rise to emotions. While there has been considerable work investigating the neural basis of emotions, progress has been hampered by several methodological limitations. For example, prior work has relied on relatively simple and isolated stimuli, which often fail to effectively capture the dynamic and multifaceted nature of emotional experiences in real-life …

Exposure Levels Of Airborne Fungi, Bacteria, And Antibiotic Resistance Genes In Cotton Farms During Cotton Harvesting And Evaluations Of N95 Respirators Against These Bioaerosols, Atin Adhikari, Pratik Banerjee, Taylor Thornton, Daleniece Higgins, Caleb Adeoye, Sonam Sherpa

Biostatistics, Epidemiology & Environmental Health Sciences: Faculty Publications

The USA is the third-leading cotton-producing country worldwide and cotton farming is common in the state of Georgia. Cotton harvest can be a significant contributor to airborne microbial exposures to farmers and nearby rural communities. The use of respirators or masks is one of the viable options for reducing organic dust and bioaerosol exposures among farmers. Unfortunately, the OSHA Respiratory Protection Standard (29 CFR Part 1910.134) does not apply to agricultural workplaces and the filtration efficiency of N95 respirators was never field-tested against airborne microorganisms and antibiotic resistance genes (ARGs) during cotton harvesting. This study addressed these two information gaps. …

Childhood Asthma-Management Practices In Rural Nigeria: Exploring The Knowledge, Attitude, And Practice Of Caregivers In Oyo State, Oyindamola Akinso, Atin Adhikari, Jingjing Yin, Joanne Chopak-Foss, Gulzar H. Shah

Biostatistics, Epidemiology & Environmental Health Sciences: Faculty Publications

Background: Caregivers of asthmatic children have a poor knowledge of proper asthma-management practices in Nigeria. This study examined the knowledge, attitudes, and practice behaviors of caregivers in the management of asthma in children under 5 years of age in Oyo State, Nigeria. Methods: While a mixed method was used in the original research, this brief describes the quantitative method used in this study to evaluate caregivers’ asthma-management practices. A 55-item questionnaire on childhood asthma knowledge, attitude, and practice was administered during child welfare-clinic visits to 118 caregivers. Data were analyzed using the IBM SPSS Version 25.0. Statistical significance was set …

Sex Differences In The Clinical Presentation Of Early Psychosis In A Primary Care Setting, Brooke Carter, Rebecca Rodrigues, Jennifer Reid, Suzanne Archie, Amanda L Terry, Lena Palaniyappan, Arlene G Macdougall, Aristotle Voineskos, Saadia Hameed Jan, Liisa Jaakkimainen, Branson Chen, Neo Sawh, Kelly K. Anderson

Epidemiology and Biostatistics Publications

Primary care is an important part of the help-seeking pathway for young people experiencing early psychosis, but sex differences in clinical presentation in these settings are unexplored. We aimed to identify sex differences in clinical presentation to primary care services in the 1-year period prior to a first diagnosis of psychotic disorder. We identified first-onset cases of non-affective psychotic disorder over a 10-year period (2005-2015) using health administrative data linked with electronic medical records (EMRs) from primary care (n = 465). Detailed information on encounters in the year prior to first diagnosis was abstracted, including psychiatric symptoms, other relevant behaviours, …

Predicting Hiv Vaccine-Mediated Protection Level To Identify Immune Correlates Using Positive Unlabeled Learning, Shiwei Xu

Dartmouth College Ph.D Dissertations

The development of a vaccine for Human Immunodeficiency Virus type 1 (HIV-1) is a crucial step in preventing the global spread of AIDS. To ensure the progress and effectiveness of this vaccine, it is essential to establish efficient biotechnology platforms and data mining methods. These methods would help identify immune characteristics that distinguish individuals with varying levels of vaccine-induced protection and determine the underlying factors that contribute to protection against HIV acquisition. While previous studies have focused on identifying immune markers associated with infection outcomes among vaccinated patients, it is important to acknowledge the limitations of traditional case-control analytical protocols …

Dimensions Of Vaccination Attitudes In Nigeria: A Study Of The Impacts Of Covid-19 Vaccine Risk Perception And Acceptance, Abiodun Musbau Lawal, Babatola Dominic Olawa, Ikenna Maximillian Odoh, Ayodeji Olorunfemi Olawole, Olubukola Ajayi, Judith Chineye Azikiwe, Israel Oluwatosin Ayodele, Emmanuel Kolawole Odusina, Thomas Attah, Ezekiel Adeyemi Odedokun, Stephen Ishola Babatunde, Teslim Alabi Oladejo, Confidence Chioma Otoghile, Saheed Abiola Saka

Kesmas

Nigeria has been affected by the COVID-19 pandemic, and vaccination is a key strategy. However, the country faces vaccination hesitancy, poor risk perception, and low acceptance. This study aimed to assess the direct and interactive impacts of COVID-19 vaccine risk perception and acceptability on COVID-19 vaccination attitudes in the general Nigerian population. In a cross-sectional approach, participants completed a structured questionnaire including demographics, COVID-19 vaccine risk perception, acceptance, and vaccination attitude from April 2-30, 2021. The sample included 1,026 participants from different ethnicities across four regions (Southwest, South, Southeast, and North Central) in Nigeria, which were selected using the convenience …

Extremely Hot Ambient Temperature And Injury-Related Mortality, Mien T N Nguyen, Man V M Nguyen, Huong V T Le, Hoai Viet Nguyen, Vu Anh Nguyen, Ngoan Tran Le

Kesmas

This pilot study aimed to evaluate the effects of extremely hot ambient temperatures on the total number of fatal injuries. Data were collected from a population-based mortality registry of Thanh Hoa, a province in the North Central region of Vietnam. This study qualified the distributed lag non-linear model and calculated the RR and 95% CI adjusted for long-term trend and absolute humidity. For the entire study population with 3,949 registered deaths due to injuries collected during 2005-2007, after the onset of extremely hot ambient temperatures, an increased risk of death was observed on the 9th day RR (95% CI) = …

Effects Of Using An Application For Postpartum Contraceptive Use In Family Planning Counseling During Pregnancy, Lia Nurcahyani, Dyah Widiyastuti, Arief Tarmansyah Iman, Yanti Cahyati, Yeni Fitrianingsih

Kesmas

A decision-making tool for family planning flipchart is used for contraceptive counseling, but the use of this flipchart is suboptimal. In this study, primary study resulted in innovative decision-making tools for family planning applications. “Si KB Pintar” was also developed, a tool that women can use to discuss contraceptives with their husbands after family planning counseling. This study analyzed the effectiveness of family planning counseling during pregnancy by applying postpartum contraceptive use. Analytical quantitative quasi-experimental methods were used with a control group design. The sampling method was two-stage sampling. In the first stage, from 22 primary health care (PHC) in …

Assessment Of Rabies Control Attitudes During The Covid-19 Pandemic Through Partial Least Square-Structural Equation Modeling, Sang Gede Purnama, Ni Wayan Arya Utami, Made Subrata, Putu Erma Pradnyani, Karang Agustina, Ibn Swacita

Kesmas

The COVID-19 pandemic disrupts rabies control activities in the community. A new approach is needed to control rabies during the COVID-19 pandemic through digital health interventions by conducting digital surveillance and education. This study aimed to determine key attitude indicators in controlling rabies during the COVID-19 pandemic. A cross-sectional study on 166 participants in Denpasar City with a total of 31 indicators measuring five variables: perceptions of the benefits of rabies control (6 indicators), perceptions of rabies risk (6 indicators), perceptions of obstacles to rabies control (5 indicators), perceptions of the need for technology (7 indicators), and attitudes toward rabies …

Ten‐Year Cardiovascular Disease Risk Score And Cognitive Function Among Older Adults: The National Health And Nutrition Examination Survey 2011 To 2014, Jingkai Wei, Hanzhang Xu, Angela D. Liese, Anwar T. Nerchant Sc.D, Mph, Dmd, Liang Wang, Chih-Hsiang Yang, Matthew C. Lohman, Monique J. Brown Ph.D., Mph, Tiansheng Wang, Daniela B. Friedman Ph.D.

Faculty Publications

BACKGROUND: The Framingham 10-year cardiovascular disease risk score, which is based on age, sex, smoking, total cholesterol, high-density lipoprotein-cholesterol, blood pressure, and diabetes, has been found to be associated with cognitive health, but these findings have not been validated in a representative sample in the United States. We aimed to examine the associations of Framingham risk score with cognitive function among older adults in a nationally representative sample, as well as by race or ethnicity, education, and family income.

METHODS AND RESULTS: A total of 2254 older adults ≥60years (57% female, 79% non-Hispanic White) in the National Health and Nutrition …

Patterns Of Hiv Disclosure And Its Impact On The Hiv Care Continuum Among Black Men Who Have Sex With Men In South Carolina, Xueying Yang Ph.D., Titilayo A. James, Monique J. Brown Ph.D., Mph, Tony Brown, Sydney Zarsadias, Ran Zhang, Fanghui Shi, Xiaoming Li Ph.D.

Faculty Publications

Addressing the psychosocial concerns of Black men who have sex with men (MSM), such as HIV disclosure, is critical for effective HIV treatment efforts. Black MSM living with HIV experience multiple psychosocial challenges, such as “triple stigma” due to their sexual orientation, racial minority status, and HIV status, which hinder their HIV disclosure and subsequent HIV care-seeking behavior. Our study sought to examine the HIV disclosure patterns and their impact on the HIV care continuum among Black MSM using a qualitative approach. Semi-structured interviews were carried out among 28 Black MSM aged ≥18 years old living in South Carolina. A …

Utilizing New Technologies To Measure Therapy Effectiveness For Mental And Physical Health, Jonathan Ossie

Dissertations

Mental health is quickly becoming a major policy concern, with recent data reporting increasing and disproportionately worse mental health outcomes, including anxiety, depression, increased substance abuse, and elevated suicidal ideation. One specific population that is especially high risk for these issues is the military community because military conflict, deployment stressors, and combat exposure contribute to the risk of mental health problems.

Although several pharmacological approaches have been employed to combat this epidemic, their efficacy is mixed at best, which has led to novel nonpharmacological approaches. One such approach is Operation Surf, a nonprofit that provides nature-based programs advocating the restorative …

A Novel Family Of Chain Binomial Models To Investigate Correlated Vaccination And Infection Rates In Sveirs Epidemic Dynamics, Divine Wanduku

Biology and Medicine Through Mathematics Conference

No abstract provided.

Optimizing Tumor Xenograft Experiments Using Bayesian Linear And Nonlinear Mixed Modelling And Reinforcement Learning, Mary Lena Bleile

Statistical Science Theses and Dissertations

Tumor xenograft experiments are a popular tool of cancer biology research. In a typical such experiment, one implants a set of animals with an aliquot of the human tumor of interest, applies various treatments of interest, and observes the subsequent response. Efficient analysis of the data from these experiments is therefore of utmost importance. This dissertation proposes three methods for optimizing cancer treatment and data analysis in the tumor xenograft context. The first of these is applicable to tumor xenograft experiments in general, and the second two seek to optimize the combination of radiotherapy with immunotherapy in the tumor xenograft …

Detecting Gene-Gene Or Gene Environment Interactions In Association With Complex Disease Outcomes, Taiwo Adetunji Famuyiwa

Theses and Dissertations

Identifying gene–gene and gene–environment interaction is complicated and gainsaying most especially because of high multifactor dimensions involve in the analysis of such combination discrediting the functionality of parametric statistical method like Logistic Regression. [22] developed a multi-factor-dimensionality reduction (MDR) method for detecting and characterizing high-order gene-gene and gene-environment interactions in case-control and discordant-sib-pair studies with relatively small samples, which is inspired by the combinatorial partitioning method of [18]. [16] proposed Generalized MDR (GMDR) framework based on the score of a generalized linear model which allows adjustment of covariates, provides a unified framework for handling both dichotomous and quantitative phenotypes. However, …

Identifying Limitations In Using Diagnostic Testing For Absorption Of Passive Maternal Immunity In Neonatal Beef Calves To Predict Pre-Weaning Disease, Alexis Charlotte Thompson

Theses and Dissertations

Calves are born agammaglobulinemic and rely on colostrum consumption for the transfer of maternal passive immunity. Calves that fail to absorb adequate amounts of maternal antibodies from colostrum are commonly referred to as having failed transfer of passive immunity (FTPI). The overall aim of this dissertation was to explore the usefulness of FTPI testing in neonatal beef calves to predict their risk for subsequent illness or death. The objectives were to evaluate the impact of FTPI on pre-weaning disease in beef and dairy calves, quantify and compare the variance in IgG concentrations measured by radial immunodiffusion and serum total protein …

Drug Ideologies Of The United States, Macy Montgomery

Helm's School of Government Conference - 2021-2024

The United States has been increasingly creating lenient drug policies. Seventeen states and Washington, the District of Columbia, legalized marijuana, and Oregon decriminalized certain drugs, including methamphetamine, heroin, and cocaine. The medical community has proven that drugs, including marijuana, have myriad adverse health side effects. This leads to two questions: Why does the United States government continue to create lenient drug policies, and what reasons do citizens give for legalizing drugs when the medical community has proven them harmful? The paper hypothesizes that the disadvantages of drug legalization outweigh its benefits because of the numerous harms it causes, such as …

Observational Study Of Organisational Responses Of 17 Us Hospitals Over The First Year Of The Covid-19 Pandemic, Esther K. Choo, Matthew Strehlow, Marina Del Rios, Evrim Oral, Ruth Pobee, Andrew Nugent, Stephen C. Lim, Christian Hext, Sarah Newhall, Diana Ko, Srihari V. Chari, Amy Wilson, Joshua J. Baugh, David Callaway, Mucio Kit Delgado, Zoe Glick, Christian J. Graulty, Nicholas Hall, Abdusebur Jemal, Madhav Kc, Aditya Mahadevan, Milap Mehta, Andrew C. Meltzer, Dar'ya Pozhidayeva, Daniel Resnick-Ault

School of Public Health Faculty Publications

Objectives The COVID-19 pandemic has required significant modifications of hospital care. The objective of this study was to examine the operational approaches taken by US hospitals over time in response to the COVID-19 pandemic. Design, setting and participants This was a prospective observational study of 17 geographically diverse US hospitals from February 2020 to February 2021. Outcomes and analysis We identified 42 potential pandemic-related strategies and obtained week-to-week data about their use. We calculated descriptive statistics for use of each strategy and plotted percent uptake and weeks used. We assessed the relationship between strategy use and hospital type, geographic region …

Inter-Rater Reliability Of Statistics Based On Reconstructed Individual Patient Data From Published Kaplan-Meier Curves, Megan E. Smith

Theses & Dissertations

Introduction: Time-to-event outcomes include two elements: an indicator variable for whether the event has taken place, and the length of time from some origin point to the occurrence of the event of interest. Due to the complexity of these data, secondary analysis methods, such as indirect comparisons and meta-analysis, are easier to perform when individual-level patient data (IPD) is available.

Objectives: In 2021, an R package IPDfromKM was published, which contains an algorithm for reconstructing IPD from a Kaplan-Meier graph. The current research aimed to investigate the reproducibility of the IPDfromKM algorithm.

Methods: Three statisticians (MS, LS, …

Trends In Resources For Neonatal Intensive Care At Delivery Hospitals For Infants Born Younger Than 30 Weeks' Gestation, 2009-2020, Nansi S. Boghossian, Marco Geraci, Ciaran S. Phibbs, Scott A. Lorch, Erika M. Edwards, Jeffrey D. Horbar

Faculty Publications

Importance: In an ideal regionalized system, all infants born very preterm would be delivered at a large tertiary hospital capable of providing all necessary care. Objective: To examine whether the distribution of extremely preterm births changed between 2009 and 2020 based on neonatal intensive care resources at the delivery hospital. Design, Setting, and Participants: This retrospective cohort study was conducted at 822 Vermont Oxford Network (VON) centers in the US between 2009 and 2020. Participants included infants born at 22 to 29 weeks' gestation, delivered at or transferred to centers participating in the VON. Data were analyzed from February to …

Characterization Of Public Opinion On Severity Of Mental Illness And Hiv Based On Individual Traits Using Hierarchical Multi-Category Probit Models, Md Moinul Ahsan

Graduate Theses and Dissertations

In this thesis, we focus on modeling categorical response variables from public opinion datasets. A hierarchical probit model was used to analyze these different variables. Particularly for multinomial data, we tried different covariate settings to see the model’s performance. For that purpose, we tried two different estimation techniques. The first algorithm uses identified parameters by fixing the first diagonal element of the covariance matrix at 1. The second algorithm uses one unidentifiable parameter and subsequently identifies the parameters by fixing the trace of the covariance matrix. The results from the simulation study confirm that the trace-restricted algorithm performs better with …

Bayesian Semi-Mechanistic Dose-Finding Designs For Phase I Oncology Trials, Chao Yang

Dissertations and Theses (Open Access)

Bayesian adaptive designs are getting more popular in research and in practice because they are flexible and efficient in evaluating an experimental drug. In oncology, despite the great advances in novel dose-finding designs, the high failure rates of clinical cancer drug development from phase I to III trials call for further improvements on novel designs, in addition to the need to promote and adopt novel designs in practice. Because anticancer agents often have a narrow therapeutic index, an accurate identification of the maximum tolerated dose (MTD) in a phase I trial is crucial for identifying a tolerable and efficacious dose …

Non-Destructive Imaging Of Phytosulfokine Trafficking In Plants Using Fiber-Optic Fluorescence Microscopy, Bernard Abakah

Electronic Theses and Dissertations

Plants secrete peptide ligands and use receptor signaling to respond to stress and control development. Understanding these phenomena is key to improving plant health and productivity for food, fiber, and energy applications. Phytosulfokine (PSK), a sulfated peptide hormone, regulates plant cell division, growth, and stress tolerance via specific phytosulfokine receptors (PSKRs). This study uses fiber-optic fluorescence microscopy to elucidate trafficking of PSK in live plants. The microscope features two-color optics and an objective lens connected to a 1-m coherent imaging fiber mounted on either a conventional upright microscope body or 5-axis positioning system (X–Y–Z plus pitch and yaw). PSK and …