Digital Commons Network^™

Bayesian Methods In Analyzing The Diagnostic Accuracy\\ For Ordinal Ratings, Yun Yang

Theses and Dissertations

This dissertation focuses on ordinal classification ratings, which are commonly used in medical practice to assess the severity of a disease or condition. For example, a group of radiologists rate a set of mammograms and assign BI-RADS (Breast Imaging Reporting Data System) score for each mammogram. A Bayesian probit hierarchical model is first proposed to analyze this type of data. It links the ordinal ratings with both rater diagnostic skills and patient latent disease severity. Each rater diagnostic skills are quantified with two parameters, diagnostic bias and diagnostic magnifier. Patient latent disease severity is assumed to follow a different normal …

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 …

Moral Injury To Inform Analysis Of Post-Traumatic Stress Disorder, Amanda Julia Manea

Senior Theses

Post-traumatic stress disorder (PTSD) is a mental health condition that almost one out of ten veterans struggle with. Although the National Center for PTSD has made extensive progress in characterizing and developing new treatments for PTSD, most veterans still experience symptoms of PTSD following treatment. Novel avenues of investigation, such as developing algorithms to review electronic health record (EHR) data and better understanding moral injury, are being pursued to address the gap that still exists when it comes to treating veterans. Moral injury is the individual evaluation of exposure to a potentially morally injurious event (PMIE) and can lead to …

That’S My Deity: An Examination Of Online Lokean Cultures Through Log-Linear Modeling, Mary Bernstein

Senior Theses

A rise in online religious communities and the growth of so-called ‘Old World’ religions are reflected in the internet’s subcultures of Neopaganism, a growing religious movement that has been documented in America since the 1960s. The religions under this umbrella movement vary drastically and include belief systems such as Wicca, Druidry, and deity worship. Belief systems under this movement lack the traditional hierarchy found in structured religion and lack a singular sacred text. As such, believers usually find and support one another not through a physical sacred place of meeting, but through an online community that acts as sacred space. …

Detecting Spatially Varying Coefficient Effects With Conditional Autoregressive Models: A Simulation Study Using Social Determinants Of Health Screening Data, Reid J. Demass

Theses and Dissertations

Generalized linear models which include spatially varying coefficient terms allow researchers to determine if the association between predictor and outcome variables vary across geographic space. Such models are particularly applicable to research with public health data where interventions and limited health care resources must be allocated carefully. The integrated nested Laplace approximation (INLA) methodology available in the R INLA package is a popular tool to estimate spatially varying coefficients. To assess the performance of the estimation procedure, patient emergency department (ED) visits were simulated from data sourced from a pilot study at Prisma Health. The INLA technique was used to …

Processed Food As A Risk Factor For The Development And Perpetuation Of Crohn's Disease-The Enigma Study, Gina L. Trakman, Winnie Y.Y. Lin, Amy L. Hamilton, Amy L. Wilson-O'Brien, Annalise Stanley, Jessica Y. Ching, Jun Yu, Joyce W.Y. Mak, Yang Sun, Junkin Niu, Yinglei Miao, Xiaoqing Lin, Rui Feng, Minhu Chen, Nitin Shivappa Mbbs, Mph, Ph.D., James R. Hébert Scd, Mark Morrison, Siew C, Ng, Michael A. Kamm

Faculty Publications

(1) Background: Developing countries have experienced a rapid recent rise in Inflammatory Bowel Disease (IBD) incidence and emerging evidence suggests processed foods and food additives may predispose one to the development and perpetuation of Crohn’s disease (CD). The aim of this study was to evaluate processed food and food additive intake in CD patients and controls, in Australia (high CD incidence), Hong Kong (intermediate incidence) and mainland China (emerging incidence). (2) Methods: In 274 CD patients (CD), 82 first-degree relatives (FDR), 83 household members (HM) and 92 healthy unrelated controls (HC) from Australia (n = 180), Hong Kong (HK) (n …

Statistical Methods For Analyzing Multi-Omics Data: Dependence Structure And Missing Values, Wenda Zhang

Theses and Dissertations

The advancements in high-throughput technologies have made it possible to generate a huge number of "omics'' data, including genomics, proteomics, transcriptomics, epigenomics, metabolomics, and microbiomics. Combining multiple data sources and performing joint analyses with all available information and the phenotypic outcome can reflect various aspects in complex biological systems, such as revealing regulation processes, discovering novel associations between biological entities, and identifying relevant biomarkers for certain diseases or phenotypic outcomes. This dissertation focuses on developing statistical models for analyzing multi-omics data. It is comprised of three topics: (1) integrative analysis for multi-omics data with missing observations in intermediate variables; (2) …

Modified Em Algorithm In Smcure Package Based On Proportional Hazards Mixture Cure Model With Offset Terms, Jiaying Yi

Theses and Dissertations

Mixture cure model is a useful method of survival analysis for population including cured proportion and uncured proportion. The R package SMCURE applies EM algorithm to estimate the coefficients of covariates in the mixture cure model. Although an offset term is specified in the SMCURE statement, the offset term is not appropriately handled in the algorithm. This thesis aims to adjust the EM algorithm for the proportional hazards mixture cure model in the SMCURE package. In addition, the offset term can be specified separately in the incidence part or the latency part. The numerical experiments include simulation study and real …

Association Between The Dietary Inflammatory Index And Gastric Disease Risk: Findings From A Korean Population-Based Cohort Study, Sundara Raj Sreeja, Trong-Dat Le, Bang Wool Eom, Seung Hyun Oh, Nitin Shivappa Mbbs, Mph, Ph.D., James R. Hébert Scd, Mi Kyung Kim

Faculty Publications

Evidence suggests that diets with high pro-inflammatory potential may play a substantial role in the origin of gastric inflammation. This study aimed to examine the association between the energy-adjusted dietary inflammatory index (E-DIITM) and gastric diseases at baseline and after a mean follow-up of 7.4 years in a Korean population. A total of 144,196 participants from the Korean Genome and Epidemiology Study_Health Examination (KoGES_HEXA) cohort were included. E-DII scores were computed using a validated semi-quantitative food frequency questionnaire. Multivariate logistic regression and Cox proportional hazards regression were used to assess the association between the E-DII and gastric disease risk. In …

Pro-Inflammatory Diet Pictured In Children With Atopic Dermatitis Or Food Allergy: Nutritional Data Of The Lina Cohort, Olivia Schütte, Larissa Bachmann, Nitin Shivappa Mbbs, Mph, Ph.D., James R. Hébert Scd, Janine F. Felix, Stefan Röder, Ulrich Sack, Michaek Borte, Wieland Kiess, Ana C. Zenclussen, Gabriele I. Stangl

Faculty Publications

Background: Lifestyle and environmental factors are known to contribute to allergic disease development, especially very early in life. However, the link between diet composition and allergic outcomes remains unclear. Methods: In the present population-based cohort study we evaluated the dietary intake of 10-year-old children and analyses were performed with particular focus on atopic dermatitis or food allergy, allergic diseases known to be affected by dietary allergens. Dietary intake was assessed via semi-quantitative food frequency questionnaires. Based on these data, individual nutrient intake as well as children’s Dietary Inflammatory Index (C-DII™) scores were calculated. Information about atopic manifestations during the first …

Diet Quality And Dietary Inflammatory Index Score Among Women’S Cancer Survivors, Sibylle Kranz, Faten Hasan, Erin Kennedy, Jamie Zoellner, Kristin A. Guertin, Nitin Shivappa Mbbs, Mph, Ph.D., James R. Hébert, Roger Anderson, Wendy Cohn

Faculty Publications

The purpose of this study was to investigate Healthy Eating Index 2015 (HEI-2015) and Energy-Adjusted Dietary Inflammatory Index (E-DIITM) scores in women's cancer survivors and to examine socio-economic (SES) characteristics associated with these two diet indices. In this cross-sectional study, survivors of women's cancers completed a demographic questionnaire and up to three 24-h dietary recalls. HEI-2015 and E-DII scores were calculated from average intakes. One-way ANOVA was used to examine the association of various demographic factors on HEI-2015 and E-DII scores. Pearson Correlation was used to calculate the correlation between the two scores. The average HEI-2015 score was 55.0 +/- …

Scanner: A Web Platform For Annotation, Visualization And Sharing Of Single Cell Rna-Seq Data, Guoshuai Cai, Xuanxuan Yu, Choonhan Youn, Jun Zhou, Feifei Xiao

Faculty Publications

In recent years, efficient scRNA-seq methods have been developed, enabling the transcriptome profiling of single cells massively in parallel. Meanwhile, its high dimensionality and complexity bring challenges to the data analysis and require extensive collaborations between biologists and bioinformaticians and/or biostatisticians. The communication between these two units demands a platform for easy data sharing and exploration. Here we developed Single-Cell Transcriptomics Annotated Viewer (SCANNER), as a public web resource for the scientific community, for sharing and analyzing scRNA-seq data in a collaborative manner. It is easy-to-use without requiring special software or extensive coding skills. Moreover, it equipped a real-time database …

The Isocaloric Substitution Of Plant-Based And Animal-Based Protein In Relation To Aging-Related Health Outcomes: A Systematic Review, Jiali Zheng, Tianren Zhu, Guanghuan Yang, Longgang Zhao, Fangyu Li, Yong-Moon Park, Fred K. Tabung, Susan E. Steck Phd, Mph, Rd, Xiaoguang Li, Hui Wang

Faculty Publications

Plant-based and animal-based protein intake have differential effects on various aging-related health outcomes, but less is known about the health effect of isocaloric substitution of plant-based and animal-based protein. This systematic review summarized current evidence of the isocaloric substitutional effect of plant-based and animal-based protein on aging-related health outcomes. PubMed and Embase databases were searched for epidemiologic observational studies published in English up to 15 March 2021. Studies that included adults ≥18 years old; use of a nutritional substitution model to define isocaloric substitution of plant protein and animal protein; health outcomes covering mortality, aging-related diseases or indices; and reported …

Association Between Diet Quality Indices And Incidence Of Type 2 Diabetes In The Melbourne Collaborative Cohort Study, Allison M. Hodge, Md Nazmul Karim, James Hébert Scd, Nitin Shivappa Mbbs, Mph, Ph.D., Barbora De Courten

Faculty Publications

Type 2 diabetes mellitus is a common condition whose incidence is increasing worldwide, and for which obesity and diet are important risk factors. The aim of this study was to assess the association of three diet quality scores with diabetes risk and how much of the association was mediated through body size. The Melbourne Collaborative Cohort Study recruited 41,513 men and women aged 40–69 years during 1990–1994. At baseline, data were collected on lifestyle and diet, anthropometric measures were performed. Incident diabetes was assessed by self-report at follow-up surveys in 1994–1998 and 2003–2007. The associations between the dietary inflammatory index …

Marginally Interpretable Models And Multilevel Models For Quantile Regression With Random-Effects, Nahid Sultana Sumi

Theses and Dissertations

The quantile regression model is an active area of statistical research that has received a lot of attention. This complements the most widely used statistical tool, that is, mean regression analysis. Quantile regression analysis It has become more flexible because of its properties that include no assumption on the distribution of the response variable, equivalent to monotone transformations, and robustness to outliers. However, regression analysis offers methodological challenges if the observations are not independent. Cluster, multilevel, and repeated measures (longitudinal data) designs introduce such dependence. The correlation between observations on the same units or clusters should be accounted for to …

Multiple Frailty Model For Spatially Correlated Interval-Censored, Wanfang Zhang

Theses and Dissertations

In this paper, we consider the problem of multiple frailty selection for general interval-censored spatial survival data, which often occurs in clinical trials and epidemiological studies. The general interval-censored data is a mixture of left-, right- and interval-censored data. We propose a Bayesian semiparametric approach based on the Cox proportional hazard model, where monotone splines were used for non-parametrical modeling of the cumulative baseline hazards where the variable selection priors were used for frailty selection. A two-stage data augmentation with Poisson latent variables is developed for efficient computation. The approach is evaluated based a simulation study and illustrated using a …

The Classification Of Basket Neural Cells In The Mammalian Neocortex, Sreya Pudi

Senior Theses

Basket neuronal cells of the mammalian neocortex have been classically categorized into two or more groups. Originally, it was thought that the large and small types are the naturally occurring groups that emerge from reasons that relate to neurobiological function and anatomical position. Later, a study based on anatomical and physiological features of these neurons introduced a third type, the net basket cell which is intermediate in size as compared to the large and small types. In this study, multivariate analysis was used to test the hypothesis that the large and small types are morphologically distinct groups. The results of …

Men’S Comfort In Distributing Or Receiving Hiv Self-Test Kits From Close Male Social Network Members In Dar Es Salaam, Tanzania: Baseline Results From The Step Project, Joseph K.B. Matovu, Gaspar Mbita, Akeen Hamilton, Frank Mhando, Wynton M. Sims, Noah Thompson, Albert N. Komba, Jackson Lija, Jiajia Zhang Ph.D., Thomas Van Den Akker, Dustin T. Duncan, Augustine T. Choko, Donaldson F. Conserve

Faculty Publications

Background

A variety of strategies have been used to reach men with HIV self-testing services, including social network-based HIV self-test kits distribution. However, few studies have assessed men’s comfort to distribute to or receive HIV self-test kits from close male friends within the same social network. In this study, we assessed men’s comfort to distribute to and/or receive HIV self-test kits from close male friends and associated factors among men who socialize in networks locally referred to as “camps” in Tanzania.

Methods

Data are from the baseline survey of a cluster-randomized controlled trial conducted in June 2019 with 18 social …

Effect Of An Antenatal Lifestyle Intervention On Dietary Inflammatory Index And Its Associations With Maternal And Fetal Outcomes: A Secondary Analysis Of The Pears Trial, Sarah Louise Killen, Catherine M. Phillips, Anna Delahunt, Cara A. Yelverton, Nitin Shivappa Mbbs, Mph, Ph.D., James Hébert Scd, Maria A. Kennelly, Martina Cronin, John Mehegan, Fionnuala M. Mcauliffe

Faculty Publications

We investigated the effect of an antenatal lifestyle intervention of a low-glycaemic index (GI) diet and physical activity on energy-adjusted dietary inflammatory index (E-DIITM) and explored its relationship with maternal and child health in women with overweight and obesity. This was a secondary analysis of 434 mother−child pairs from the Pregnancy Exercise and Nutrition Study (PEARS) trial in Dublin, Ireland. E-DII^TM scores were calculated for early (10–16 weeks) and late (28 weeks) pregnancy. Outcomes included lipids, inflammation markers, insulin resistance, mode of delivery, infant size, pre-eclampsia, and gestational diabetes. T-tests were used to assess changes in E-DII^TM. …

Associations Between Fasting Duration, Timing Of First And Last Meal, And Cardiometabolic Endpoints In The National Health And Nutrition Examination Survey, Michael David Wirth, Longgang Zhao, Gabrielle Turner-Mcgrievy, Andrew Ortaglia

Faculty Publications

Background: Research indicates potential cardiometabolic benefits of energy consumption earlier in the day. This study examined the association between fasting duration, timing of first and last meals, and cardiometabolic endpoints using data from the National Health and Nutrition Examination Survey (NHANES). Methods: Cross-sectional data from NHANES (2005–2016) were utilized. Diet was obtained from one to two 24-h dietary recalls to characterize nighttime fasting duration and timing of first and last meal. Blood samples were obtained for characterization of C-reactive protein (CRP); glycosylated hemoglobin (HbA1c %); insulin; glucose; and high-density lipoprotein (HDL), low-density lipoprotein (LDL), and total cholesterol. Survey design procedures …

Cognitive Complaints In Age-Related Chronic Conditions: A Systematic Review, Nikki L. Hill, Sakshi Bhargava, Monique J. Brown Ph.D., Mph, Hyejin Kim, Iris Bhang, Katilyn Mullin, Kathleen Phillips, Jacqueline Mogle

Faculty Publications

Introduction

Cognitive complaints in older adults may be indicative of progressive cognitive decline including Alzheimer’s disease (AD), but also occur in other age-related chronic conditions, complicating identification of early AD symptoms. To better understand cognitive complaints in aging, we systematically reviewed the evidence to determine their prevalence and characterization among older adults with the most common age-related chronic conditions.

Methods

This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement and the review protocol was prospectively registered with PROSPERO (ID: CRD42020153147). Searches were conducted in PubMed, CINAHL, PsycINFO, Web of Science, and …

Associations Between Family-Based Stress And Dietary Inflammatory Potential Among Families With Preschool-Aged Children, Valerie Hruska, Nitin Shivappa Mbbs, Mph, Ph.D., James R. Hébert Scd, Alison M. Duncan, Jess Hines, David W. L. Ma

Faculty Publications

Chronic stress is known to influence dietary choices, and stressed families often report poorer diet quality; however, little is known about how family-based stress is linked with dietary patterns that promote inflammation. This study investigated associations between family-based stress and the inflammatory potential of the diet among preschool-aged children and their parents. Parents (n = 212 mothers, n = 146 fathers) and children (n = 130 girls, n = 123 boys; aged 18 months to 5 years) from 241 families participating in the Guelph Family Health Study were included in the analyses. Parents reported levels of parenting distress, depressive symptoms, …

Dietary Inflammatory Index Is Associated With Inflammation In Japanese Men, Ayaka Kotemori, Norie Sawada, Motoki Iwasaki, Taiki Yamaji, Nitin Shivappa Mbbs, Mph, Ph.D., James Hébert Scd, Junko Ishihara, Manami Inoue, Shoichiro Tsugane

Faculty Publications

Background: Dietary components are known to affect chronic low-grade inflammation status. The dietary inflammatory index (DII®) was developed to measure the potential impact of a diet on an individual's inflammatory status, and it has been validated mainly in Western countries.

Objective: This study aimed to examine the validity of the energy-adjusted DII (E-DIITM) using high-sensitivity C-reactive protein (hs-CRP) concentration in Japanese men and women.

Methods: In total, 6,474 volunteers from a cancer-screening program (3,825 men and 2,649 women) completed a food frequency questionnaire (FFQ) and their hs-CRP concentrations were evaluated. E-DII scores were calculated on the basis of 30 food …

Change In Dietary Inflammatory Index Score Is Associated With Control Of Long-Term Rheumatoid Arthritis Disease Activity In A Japanese Cohort: The Tomorrow Study, Yoshinari Matsumoto, Nitin Shivappa Mbbs, Mph, Ph.D., Yuko Sugioka, Masahiro Tada, Tadashi Okano, Kenji Mamoto, Kentaro Inui, Daiki Habu, James R. Hébert Scd, Tatsuya Koike

Faculty Publications

Background: The dietary inflammatory index (DII®), a quantitative measure of the inflammatory potential of daily food and nutrient intake, and associations between a variety of health outcomes have been reported. However, the association between DII score and disease activity of rheumatoid arthritis (RA) is unclear. Therefore, this study was designed to test whether higher DII score contributes to disease activity and as a corollary, y, whether reducing DII score helps to achieve or maintain low disease activity or remission in patients with RA.

Methods: We performed a cross-sectional and longitudinal analysis using 6 years of data (from 2011 to 2017) …

Dietary Inflammatory Index Is Related To Heart Failure Risk And Cardiac Function: A Case-Control Study In Heart Failure Patients, Jalal Moludi, Nitin Shivappa Mbbs, Mph, Ph.D., Soghra Alisgharzadeh, James R. Hébert Scd, Mohammad Alizadeh

Faculty Publications

Aims: Previous studies suggest that diet and inflammation are important risk factors for heart failure (HF); however, the associations remain unclear. The Dietary Inflammatory Index (DII®) was established to measure the inflammatory capacity of individuals' diet. This study aimed to explore the DII in HF subjects compared with controls. Methods and Results: We conducted a case–control (116 cases and 113 controls) study that recruited in the similar clinics. DII scores were calculated based on dietary intakes. N-Terminal pro-brain natriuretic peptide (NT-proBNP) levels and ejection fraction (EF) were assessed in both groups. In order to analyze DII scores with HF as …

A Simulation-Based Study Of Location-Shift Models Under Non-Normal Conditions, Ummay Khayrunnesa Anika

Theses and Dissertations

In this study, we compare ordinary least squares (OLS), generalized least squares (GLS), M- and quantile regression (QR) estimators for a continuous response variable under different scenarios by conducting a simulation study. We assess the performance of the estimators in terms of bias, average distance, mean squared error, coverage probability, and ratio of estimated standard error and empirical standard deviation. OLS estimator performs the best when the errors are homoscedastic normal or homoscedastic but skewed (exponential) having no outliers. GLS estimator shows good comparative results to QR when the errors are heteroscedastic normal or heteroscedastic heavy-tailed (t-distributed). The most satisfactory …

Statistical Analysis Of A Joint Stochastic Model For Recurrent Competing Risks, Longitudinal Marker, And Health Status, Lili Tong

Theses and Dissertations

Joint modeling approach has been applied in many applications in biomedical, reliability, and social-economic research. For example, in clinical trials and medical research, different kinds of patient information are gathered over time, such as recurrent competing risk events (e.g., relapses of different types of tumor), longitudinal marker (e.g., tumor size), and health status (e.g., if a patient is dead or not). These data are usually correlated, joint models enable the analysis of these correlated data. This dissertation proposes a class of joint dynamic models for simultaneously modeling the three types of processes: a recurrent competing risk (RCR) process, a health …

Bayesian Nonparametric Model For Functional Data Analysis, Tahmidul Islam

Theses and Dissertations

Functional data analysis (FDA) experienced a burst of growth after Ramsay and Silverman published their textbook in 1997. Functional data analysis interests researchers because of the challenges it adds to well-established multivariate analysis. Unlike finite dimensional random vectors, we visualize infinite dimensional random functions; for example, curves, images, brain scans, etc. A vast amount of literature have been dedicated to developing models for functional data. The ideas are mostly based on basis function representations and kernel-based nonparametric methods. In this dissertation, we propose a Bayesian treatment of nonparametric functional data analysis by introducing a Gaussian process (GP) over the space …

Neighborhood Characteristics And The Mental Health Of Caregivers Cohabiting With Care Recipients Diagnosed With Alzheimer’S Disease, Dana M. Alhasan, Jana A. Hirsch, Chandra L. Jackson, Margaret Chandlee Miller, Bo Cai Ph.D., Matthew C. Lohman Ph.D.

Faculty Publications

While studies have documented the influence of caregiver and care recipient factors on caregiver health, it is important to address the potential impact of neighborhood contexts. This study estimated the cross-sectional associations between neighborhood characteristics and mental health among caregivers cohabiting with Alzheimer’s disease care recipients that were experiencing severe or non-severe neuropsychiatric symptoms (NPSs) (e.g., aggression/anxiety). We obtained data collected in 2010 on caregivers and care recipients (n

While studies have documented the influence of caregiver and care recipient factors on caregiver health, it is important to address the potential impact of neighborhood contexts. This study estimated the cross-sectional …

Time-Varying Insomnia Symptoms And Incidence Of Cognitive Impairment And Dementia Among Older Us Adults, Nicholas V. Resciniti, Valerie Yelverton, Bezawit Eyob Kase, Jiajia Zhang, Matthew C. Lohman

Faculty Publications

There is conflicting evidence regarding the association between insomnia and the onset of mild cognitive impairment (MCI) or dementia. This study aimed to evaluate if time-varying insomnia is associated with the development of MCI and dementia. Data from the Health and Retirement Study (n = 13,833) from 2002 to 2014 were used (59.4% female). The Brief Insomnia Questionnaire was used to identify insomnia symptoms which were compiled in an insomnia severity index, ranging from 0 to 4. In analysis, participants’ symptoms could vary from wave-to-wave. Dementia was defined using results from the Health and Retirement Study (HRS) global cognitive …