Medicine and Health Sciences Commons^™

The Performance Of Marginal Modeling Methods For Rare Events With Application To Opioid Overdose Mortality And Morbidity, Shawn Nigam

Theses and Dissertations--Epidemiology and Biostatistics

Opioid misuse is a nationwide epidemic, with Kentucky having one of the highest opioid overdose-related fatality rates across all US states. These rates have increased significantly over the past decade, with particularly large increases during the COVID-19 pandemic. This dissertation aims to study the behavior of these increases and the methods for the marginal modeling of count outcomes related to opioid overdose.

Opioid overdose-related fatality rates in Kentucky increased significantly during the COVID-19 pandemic. In this chapter, we characterize the changes in opioid overdose fatality rates in Kentucky and identify associations between potential factors and fatality rates. County-level opioid overdose …

Maternal Occupation And Pediatric Brain Cancer In Kentucky, Mary Elizabeth Begley

Theses and Dissertations--Epidemiology and Biostatistics

Pediatric brain cancer is a rare and potentially deadly diagnosis that affects children in Kentucky at a higher incidence than those nationally. Limited exposures in children early in life to warrant the development and progression of brain cancer point to the role parental exposures experienced in the period prior to conception and throughout pregnancy may play in its development. Many of these exposures may be experienced through occupation.

Data on a subset of pediatric brain cancer cases in Kentucky was compared to all cases diagnosed in the state from 1995 to 2019. Survey data of the study sample was collected …

Potential Alzheimer's Disease Plasma Biomarkers, Taylor Estepp

Theses and Dissertations--Epidemiology and Biostatistics

In this series of studies, we examined the potential of a variety of blood-based plasma biomarkers for the identification of Alzheimer's disease (AD) progression and cognitive decline. With the end goal of studying these biomarkers via mixture modeling, we began with a literature review of the methodology. An examination of the biomarkers with demographics and other health factors found evidence of minimal risk of confounding along the causal pathway from biomarkers to cognitive performance. Further study examined the usefulness of linear combinations of biomarkers, achieved via partial least squares (PLS) analysis, as predictors of various cognitive assessment scores and clinical …

A Novel Nonparametric Test For Heterogeneity Detection And Assessment Of Fluid Removal Among Crrt Patients In Icu, Shaowli Kabir

Theses and Dissertations--Epidemiology and Biostatistics

Over the past decade acute kidney injury (AKI) has been occurring among 20%-50% of patients admitted to the intensive care unit (ICU) in United States. Continuous renal replacement therapy (CRRT) has become a popular treatment method among these critically ill patients. But there are multiple complications in implementing this treatment, including discrepancies in practiced and prescribed fluid removal, possibly related to the heterogeneity among these patients. With mixture modeling there have been several techniques in detecting heterogeneity with their specific limitations. In this dissertation a novel nonparametric ‘d test’ will be used to detect heterogeneity among CRRT patients in ICU. …

Opioid Use Disorder Treatment With Buprenorphine: Analysis Of Treatment Utilization And Associated Outcomes In Kentucky, Feitong Lei

Theses and Dissertations--Epidemiology and Biostatistics

Opioid use disorder (OUD) is chronic opioid use that results in clinically significant suffering, impairment, or even death. The opioid epidemic in the United States has become a public health and economic crisis, affecting patients' well-being and the nation's overall health and welfare. Eastern Kentucky was among the first regions affected by the opioid crisis, and Kentucky has historically ranked among the top five states for age-adjusted drug overdose mortality rate.

There are three medications (buprenorphine, methadone, naltrexone) approved by the U.S. Food and Drug Administration to treat OUD. As a partial opioid agonist, buprenorphine is a safe medication for …

Addressing Ascertainment Bias In The Study Of Cardiovascular Disease Burden In Opioid Use Disorders - Application Of Natural Language Processing Of Electronic Health Records, Jade Huang Singleton

Theses and Dissertations--Epidemiology and Biostatistics

In the United States, the prevalence of long-term exposure to opioid drugs, for both medically and nonmedically indicated purposes, has increased considerably since the mid-1990’s. Concerns have emerged about the potential health effects of opioid use. There is also growing interest in other possible connections with opioid use including cardiovascular disease. Electronic health records (EHR) contain information about patient care in the form of structured codes and unstructured notes. Natural language processing (NLP) provides a tool for processing unstructured textual data in EHR clinical notes and extracts useful information for research with structured formats. The purpose of this dissertation was …

An Assessment Of Kentucky Birth Records, Focusing On Early-Onset Hypertensive Disorders Of Pregnancy, Environmental Metal Exposures, And Geocoding Precision, 2008-2017, Courtney J. Walker

Theses and Dissertations--Epidemiology and Biostatistics

Using live and stillbirth records from Kentucky (2008-2017), this dissertation assessed the county-level prevalence and geospatial patterns of early-onset hypertensive disorders of pregnancy (eHDP); examined the geocoding precision of addresses recorded on birth records, and evaluated the association between individual risk factors and environmental metal exposures on eHDP prevalence. After adjusting for maternal demographic factors and pre-existing health conditions, we observed that eHDP prevalence was 38% higher (aPR=1.38, 95%CI:1.16, 1.64) in counties with the highest prevalence of married women (> 53.8%) compared to lower prevalence areas (31.6%) had a 20% higher prevalence of eHDP(aPR=1.20, 95%CI:1.00, 1.44) compared to counties with …

Environmental Respiratory Exposures And Pulmonary Function Among Residents Of Rural Appalachia, Kentucky, John C. Flunker

Theses and Dissertations--Epidemiology and Biostatistics

Introduction

Resource extraction exposures are hypothesized to promote adverse respiratory health outcomes among residents of rural Appalachia, yet no studies to date have simultaneously quantified small-scale geographic variation in residential exposure, individual level health factors, and respiratory health outcomes.

Methods

The Mountain Air Project (MAP) is a community engaged cross-sectional study based in Harlan and Letcher counties of Southeastern Kentucky. MAP utilized a novel small-scale method to define residential exposure boundaries: hydrologic unit code (HUC), which represents distinct drainages (AKA “hollows”) where residents cluster. We assigned the HUC level density of active and abandoned surface and underground mining, oil/gas wells, …

Enhancing Drug Overdose Mortality Surveillance Through Natural Language Processing And Machine Learning, Patrick J. Ward

Theses and Dissertations--Epidemiology and Biostatistics

Epidemiological surveillance is key to monitoring and assessing the health of populations. Drug overdose surveillance has become an increasingly important part of public health practice as overdose morbidity and mortality has increased due in large part to the opioid crisis. Monitoring drug overdose mortality relies on death certificate data, which has several limitations including timeliness and the coding structure used to identify specific substances that caused death. These limitations stem from the need to analyze the free-text cause-of-death sections of the death certificate that are completed by the medical certifier during death investigation. Other fields, including clinical sciences, have utilized …

Multiple Proteinopathies And Their Role In Cognitive Impairment And Neurodegenerative Diseases, Shama D. Karanth

Theses and Dissertations--Epidemiology and Biostatistics

Most age-related neurodegenerative disorders are associated with the aggregation of misfolded and aberrant proteins. Alzheimer’s disease (AD) is one of the most common neurodegenerative disorders and is highly prevalent in older adults. Neuropathologically, AD is characterized by the accumulation of amyloid-β (Aβ) plaques and neurofibrillary tangles (NFTs). Other misfolded proteins, including α-synuclein and transactive response DNA-binding protein 43 (TDP-43), are also commonly observed in aged brains. Aberrant α-synuclein has been associated with Parkinson's disease, Dementia with Lewy bodies, and multiple system atrophy, whereas TDP-43 has been associated with multiple neurological diseases, the most common of which was designated as limbic-predominant, …

Investigations Into The Genetics Of Mixed Pathologies In Dementia, Adam Dugan

Theses and Dissertations--Epidemiology and Biostatistics

Alzheimer’s disease (AD) is an irreversible, progressive brain disorder that leads to a loss of memory and thinking skills. While tremendous progress has been made in our understanding of the genetics underlying AD, currently known genetic variants explain only approximately 30% of the heritable risk of developing AD. One hurdle to AD research is that it can only be definitively diagnosed at autopsy, making cruder, clinic-based diagnoses more common. In recent years, several brain pathologies that mimic AD’s clinical presentation have been identified including brain arteriolosclerosis, hippocampal sclerosis (HS), and, most recently, limbic-predominant age-related TDP-43 encephalopathy (LATE). It has become …

Sexual Behaviors Associated With Online Partner-Seeking Among Men Who Have Sex With Men From Small/Midsized Towns Or Rural Areas In Kentucky, Vira Pravosud

Theses and Dissertations--Epidemiology and Biostatistics

The HIV epidemic remains one of the most significant public health issues in the United States, particularly among men who have sex with men (MSM). New avenues for partner-seeking have emerged over the past three decades, including through the Internet, social media, and geosocial networking applications. Consisting of three cross-sectional studies, this dissertation research aimed to determine associations between the use of various online tools for partner-seeking (hereafter collectively referred to as “apps”) and HIV-related sexual behaviors among 252 young adult MSM residing in small/midsized towns or rural areas in Central Kentucky, a group that has been under-represented in the …

Evaluating The Incidence Of Melanoma And Lung Cancer Of Current And Former Active-Duty U.S. Military Who Were Deployed In Support Of Operation Enduring Freedom And Operation Iraqi Freedom, Brian Kovacic

Theses and Dissertations--Epidemiology and Biostatistics

The incidence of melanoma and lung cancer has been gradually increasing in the United States over the past three decades with the reputed causes due to etiological and environmental exposures, and tobacco usage. There has been concern that melanoma and lung cancer incidence among military personnel may be associated with deployment to environments with intense sun exposure and increased smoking rates due to post-traumatic stress disorder. The aim of this study was to examine associations between deployment in support of Operation Enduring Freedom (OEF) or Operation Iraqi Freedom (OIF), from 2001 through 2015, with subsequent melanoma and lung cancer incidence. …

Opioid Use In Vulnerable Populations, Gyeon Oh

Theses and Dissertations--Epidemiology and Biostatistics

Opioid-related negative health outcomes, such as substance use disorder, misuse, and overdose deaths, have risen as long-term opioid use has increased. The benefit of using long-term opioids for pain is yet to be established. The Centers for Disease Control and Prevention provides guidelines for opioid prescribing in chronic pain, but detailed recommendations on opioid prescribing for vulnerable populations are missing due to lack of evidence-based studies. The purpose of this dissertation is to describe patterns and predictors of opioid use and assess outcomes related to prescribing opioid medications in vulnerable populations, specifically older adults with various levels of cognitive function, …

Evaluating The Impacts Of Antidepressant Use On The Risk Of Dementia, Ran Duan

Theses and Dissertations--Epidemiology and Biostatistics

Dementia is a clinical syndrome caused by neurodegeneration or cerebrovascular injury. Patients with dementia suffer from deterioration in memory, thinking, behavior and the ability to perform everyday activities. Since there are no cures or disease-modifying therapies for dementia, there is much interest in identifying modifiable risk factors that may help prevent or slow the progression of cognitive decline. Medications are a common focus of this type of research.

Importantly, according to a report from the Centers for Disease Control and Prevention (CDC), 19.1% of the population aged 60 and over report taking antidepressants during 2011-2014, and this number tends to …

Estimating Disease Severity, Symptom Burden And Health-Related Behaviors In Patients With Chronic Pulmonary Diseases, Radmila Choate

Theses and Dissertations--Epidemiology and Biostatistics

Chronic pulmonary diseases include a wide range of illnesses that differ in etiology, prevalence, symptomatology and available therapy. A common link among these illnesses is their impact on patients’ vital function of breathing, high symptom burden and significantly impaired quality of life.

This dissertation research evaluates disease severity, symptom burden and health behaviors of patients with three different chronic pulmonary conditions. First, alpha-1 antitrypsin deficiency (AATD) is an inherited condition that typically is associated with an increased risk of early onset pulmonary emphysema. This study examines differences in demographic, health, and behavioral characteristics and compares clinical outcomes and health related …

Differential Abundance And Clustering Analysis With Empirical Bayes Shrinkage Estimation Of Variance (Dasev) For Proteomics And Metabolomics Data, Zhengyan Huang

Theses and Dissertations--Epidemiology and Biostatistics

Mass spectrometry (MS) is widely used for proteomic and metabolomic profiling of biological samples. Data obtained by MS are often zero-inflated. Those zero values are called point mass values (PMVs). Zero values can be further grouped into biological PMVs and technical PMVs. The former type is caused by the absence of components and the latter type is caused by detection limit. There is no simple solution to separate those two types of PMVs. Mixture models were developed to separate the two types of zeros apart and to perform the differential abundance analysis. However, we notice that the mixture model can …

Using Prescription Drug Monitoring Data To Inform Population Level Analysis Of Opioid Analgesic Utilization, Huong T. T. Luu

Theses and Dissertations--Epidemiology and Biostatistics

Increased opioid analgesic (OA) prescribing has been associated with increased risk of prescription opioid diversion, misuse, and abuse. States established prescription drug monitoring programs (PDMPs) to collect and analyze electronic records for dispensed controlled substances to reduce prescription drug abuse and diversion. PDMP data can be used by prescribers for tracking patient’s history of controlled substance prescribing to inform clinical decisions.

The studies in this dissertation are focused on the less utilized potential of the PDMP data to enhance public health surveillance to monitor OA prescribing and co-prescribing and association with opioid overdose mortality and morbidity. Longitudinal analysis of OA …

An Exploratory Statistical Method For Finding Interactions In A Large Dataset With An Application Toward Periodontal Diseases, Joshua Lambert

Theses and Dissertations--Epidemiology and Biostatistics

It is estimated that Periodontal Diseases effects up to 90% of the adult population. Given the complexity of the host environment, many factors contribute to expression of the disease. Age, Gender, Socioeconomic Status, Smoking Status, and Race/Ethnicity are all known risk factors, as well as a handful of known comorbidities. Certain vitamins and minerals have been shown to be protective for the disease, while some toxins and chemicals have been associated with an increased prevalence. The role of toxins, chemicals, vitamins, and minerals in relation to disease is believed to be complex and potentially modified by known risk factors. A …

Statistical Analyses To Detect And Refine Genetic Associations With Neurodegenerative Diseases, Yuriko Katsumata

Theses and Dissertations--Epidemiology and Biostatistics

Dementia is a clinical state caused by neurodegeneration and characterized by a loss of function in cognitive domains and behavior. Alzheimer’s disease (AD) is the most common form of dementia. Although the amyloid β (Aβ) protein and hyperphosphorylated tau aggregates in the brain are considered to be the key pathological hallmarks of AD, the exact cause of AD is yet to be identified. In addition, clinical diagnoses of AD can be error prone. Many previous studies have compared the clinical diagnosis of AD against the gold standard of autopsy confirmation and shown substantial AD misdiagnosis Hippocampal sclerosis of aging (HS-Aging) …

Methods For Determining Time To Return To Play After Recreational Injury In Field And Court Sport Athletes, Sarah N. Morris

Theses and Dissertations--Epidemiology and Biostatistics

An observational study was used to illustrate the application of time to event analysis methods to return to play; a secondary data analysis of athlete injury data from the High School RIO^TM Injury Surveillance System (ISS) database was conducted. National Athletic Trainers’ Association (NATA)-certified athletic trainers from approximately 100 high schools in the US enroll their school in the system and complete the online “Exposure Report Form” for reportable injuries each week. New lateral ankle sprains and single-ligament knee injuries experienced by high school athletes during regularly scheduled participation in school-sanctioned sports for seven academic years (2005-2006 through 2011-2012) …

Mixture Modeling With Applications In Alzheimer's Disease, Frank Appiah

Theses and Dissertations--Epidemiology and Biostatistics

This dissertation involves an application of mixture of regression models to 114 individuals who are cognitively intact (from the Alzheimer's Disease and Neuroimaging Initiative-ADNI, data). The correct number of components in the model were estimated with the Singular BIC (SBIC), marking the first time it has been applied to such a problem. The smallest true model in conjunction with the approximation of SBIC was fixed at 1. The resulting posterior probabilities from the model were used to estimate the probability of a person transitioning and risk plots were obtained that could in principle be used by clinicians to identify patients …

Examining The Activities, Effectiveness, And Contribution Of Local Health Departments Using A National Longitudinal Survey Of Public Health Systems, Lava R. Timsina

Theses and Dissertations--Epidemiology and Biostatistics

Health services research and public health services and systems research in the past have contributed to a strong foundation of evidence-based progress in organizing, financing, and delivering medical care and public health strategies across the United States. The purpose of this dissertation was to examine disparities in public health systems and in the delivery of population health services in communities served by these systems using nationally representative data from the National Longitudinal Survey of Local Public Health Systems (1998, 2006, 2012, and 2014).

Data from the 1998 cohort of 497 local health jurisdictions serving at least 100,000 residents, and from …

Modeling Dementia Risk, Cognitive Change, Predictive Rules In Longitudinal Studies, Xiuhua Ding

Theses and Dissertations--Epidemiology and Biostatistics

Dementia is increasing recognized as a major problem to public health worldwide. Prevention and treatment strategies are in critical need. Nowadays, research for dementia usually featured as complex longitudinal studies, which provide extensive information and also propose challenge to statistical methodology. The purpose of this dissertation research was to apply statistical methodology in the field of dementia to strengthen the understanding of dementia from three perspectives: 1) Application of statistical methodology to investigate the association between potential risk factors and incident dementia. 2) Application of statistical methodology to analyze changes over time, or trajectory, in cognitive tests and symptoms. 3) …

Evaluating A Bystander Intervention Program On Reproductive Coercion: Using Quasi-Experimental Design Strategies To Address Methodologic Issues In Randomized Community Prevention Trials, Catherine P. Starnes

Theses and Dissertations--Epidemiology and Biostatistics

Community (or cluster) randomized trials are trials in which communities or groups of individuals (clusters) are randomized to receive the intervention of interest. Community randomized trials frequently more closely resemble a natural experiment than a randomized controlled trial (RCT) following intervention allocation. In particular, the effects of non-compliance can pose methodologic challenges in estimating the intervention effect which may require a quasiexperimental approach in order to minimize bias.

The motivating example to illustrate these issues is the Green Dot High School (GDHS) study. The GDHS study was a longitudinal, cluster-randomized controlled trial designed to assess the effectiveness of a bystander …

Exploration Of The Misuse, Abuse, And Diversion Of Gabapentin, Rachel Vickers Smith

Theses and Dissertations--Epidemiology and Biostatistics

Gabapentin is currently approved by the Food and Drug Administration (FDA) as an adjunctive anti-convulsant and an analgesic for post-herpetic neuralgia. Though gabapentin was initially presumed to have limited or no abuse potential, which may have contributed to its widespread off-label prescribing, there have been increasing anecdotal and published reports of its misuse by substance abusers in the community and penal system. However, to date, there has been limited systematic evaluation of the scope and risk of gabapentin misuse and its associated effects. This dissertation assesses the etiology and prevalence of gabapentin misuse, abuse, and diversion in a multi-faceted approach, …

Developments In Nonparametric Regression Methods With Application To Raman Spectroscopy Analysis, Jing Guo

Theses and Dissertations--Epidemiology and Biostatistics

Raman spectroscopy has been successfully employed in the classification of breast pathologies involving basis spectra for chemical constituents of breast tissue and resulted in high sensitivity (94%) and specificity (96%) (Haka et al, 2005). Motivated by recent developments in nonparametric regression, in this work, we adapt stacking, boosting, and dynamic ensemble learning into a nonparametric regression framework with application to Raman spectroscopy analysis for breast cancer diagnosis. In Chapter 2, we apply compound estimation (Charnigo and Srinivasan, 2011) in Raman spectra analysis to classify normal, benign, and malignant breast tissue. We explore both the spectra profiles and their derivatives to …

The Non-Steroidal Anti-Inflammatory Drugs-Myocardial Infarction Association: An Investigation Of Kentucky Medicaid Prescription Claims, Leonard A. Gordon

Theses and Dissertations--Epidemiology and Biostatistics

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most widely used medications globally. There are generally two types: selective (COX-2) and traditional NSAIDs (COX-1). They are primarily used for the treatment of pain. They gained attention after a study about their basic mechanisms highlighted their toxicity.

Several studies have reported an association between NSAIDs and risk of myocardial infarction (MI). However, the direction of the relationship is not conclusive. Further studies are needed to ascertain the direction of this relationship and evaluate the present situation with available drugs. Due to the seriousness of cardiovascular diseases as one of the leading cause …

Evidence-Based Hospitals, David R. Bardach

Theses and Dissertations--Epidemiology and Biostatistics

In 2011 the University of Kentucky opened the first two inpatient floors of its new hospital. With an estimated cost of over $872 million, the new facility represents a major investment in the future of healthcare in Kentucky. This facility is outfitted with many features that were not present in the old hospital, with the expectation that they would improve the quality and efficiency of patient care. After one year of occupancy, hospital administration questioned the effectiveness of some features. Through focus groups of key stakeholders, surveys of frontline staff, and direct observational data, this dissertation evaluates the effectiveness of …

Nonlinear Hierarchical Models For Longitudinal Experimental Infection Studies, Michael David Singleton

Theses and Dissertations--Epidemiology and Biostatistics

Experimental infection (EI) studies, involving the intentional inoculation of animal or human subjects with an infectious agent under controlled conditions, have a long history in infectious disease research. Longitudinal infection response data often arise in EI studies designed to demonstrate vaccine efficacy, explore disease etiology, pathogenesis and transmission, or understand the host immune response to infection. Viral loads, antibody titers, symptom scores and body temperature are a few of the outcome variables commonly studied. Longitudinal EI data are inherently nonlinear, often with single-peaked response trajectories with a common pre- and post-infection baseline. Such data are frequently analyzed with statistical methods …