Statistics and Probability Commons^™

Causal Mediation Analysis For Difference-In-Difference Design And Panel Data, Pei-Hsuan Hsia, An-Shun Tai, Chu-Lan Michael Kao, Yu-Hsuan Lin, Sheng-Hsuan Lin

Harvard University Biostatistics Working Paper Series

Advantages of panel data, i.e., difference in difference (DID) design data, are a large sample size and easy availability. Therefore, panel data are widely used in epidemiology and in all social science fields. The literatures on causal inferences of panel data setting or DID design are growing, but no theory or mediation analysis method has been proposed for such settings. In this study, we propose a methodology for conducting causal mediation analysis in DID design and panel data setting. We provide formal counterfactual definitions for controlled direct effect and natural direct and indirect effect in panel data setting and DID …

Development Of A Multiplex Real-Time Pcr Assay For Predicting Macrolide And Tetracycline Resistance Associated With Bacterial Pathogens Of Bovine Respiratory Disease, Enakshy Dutta, John Loy, Caitlyn A. Deal, Emily L. Wynn, Michael L. Clawson, Jennifer Clarke, Bing Wang

Department of Statistics: Faculty Publications

Antimicrobial resistance (AMR) in bovine respiratory disease (BRD) is an emerging concern that may threaten both animal and public health. Rapid and accurate detection of AMR is essential for prudent drug therapy selection during BRD outbreaks. This study aimed to develop a multiplex quantitative real-time polymerase chain reaction assay (qPCR) to provide culture-independent information regarding the phenotypic AMR status of BRD cases and an alternative to the gold-standard, culture-dependent test. Bovine clinical samples (297 lung and 111 nasal) collected in Nebraska were subjected to qPCR quantification of macrolide (MAC) and tetracycline (TET) resistance genes and gold-standard determinations of AMR of …

Indispensable Statistics For The Behavioral Sciences ~With Spss 26, Howard Reid Ph.D.

Open Educational Resources (OER)

While there are many fine introductory statistics books, undergraduate students often continue to view statistics courses negatively. And many fear they will be unable to master the basic level of understanding that is essential to progress in their majors. The present text is an attempt to rethink what students majoring in the behavioral sciences absolutely must learn in an introductory statistics course and how best to organize the presentation of this material so they can succeed in their chosen field of study.

Every book is written from some perspective. The perspective of this book is that a first course in …

A Review Of Spatial Causal Inference Methods For Environmental And Epidemiological Applications, Brian J. Reich, Shu Yang, Yawen Guan, Andrew B. Giffin, Matthew J. Miller, Ana Rappold

Department of Statistics: Faculty Publications

The scientific rigor and computational methods of causal inference have had great impacts on many disciplines but have only recently begun to take hold in spatial applications. Spatial causal inference poses analytic challenges due to complex correlation structures and interference between the treatment at one location and the outcomes at others. In this paper, we review the current literature on spatial causal inference and identify areas of future work. We first discuss methods that exploit spatial structure to account for unmeasured confounding variables. We then discuss causal analysis in the presence of spatial interference including several common assumptions used to …

Treatment Of Inconclusive Results In Firearms Error Rate Studies, Heike Hofmann, Susan Vanderplas, Alicia L. Carriquiry

Department of Statistics: Faculty Publications

★ Defining error rates for firearms evidence ★ Impact of inconclusive decisions on error rates ★ Predictive probabilities and errors

Moving Past ‘One Size Fits All’: Developing A Trajectory Deviance Index For Dynamic Measurement Modeling, Yixiao Dong

Electronic Theses and Dissertations

Dynamic Measurement Modeling (DMM) is a recently developed measurement framework for gauging developing constructs (e.g., learning capacity) that conventional single-timepoint tests cannot assess. Like most measurement models, overall model fit indices of DMM do not indicate the measurement appropriateness for each included student. For this reason, other measurement modeling paradigms (e.g., Item-Response Theory; IRT) utilize person-fit or model appropriateness statistics to indicate whether a measurement model appropriately describes the data from each individual student. However, within the extant DMM framework, no statistical index has yet been developed for this purpose. Thus, the current project advanced a person-specific DMM Trajectory Deviance …

Evaluation Of The Effect Of The Clinical-Decision-Support Systems On Diabetes Management: A Multivariate Meta-Analysis Comparison With Univariate Meta-Analysis, Abdelfattah Elbarsha

Electronic Theses and Dissertations

The advantage of using meta-analysis lies in its ability in providing a quantitative summary of the findings from multiple studies. The aim of this dissertation was first to conduct a simulation study in order to understand what factors (sample size, between-study correlation, and percent of missing data) have a significant effect on meta-analysis estimates and whether using univariate or multivariate meta-analysis would produce different estimates.

The second goal of this study was to evaluate the effect of clinical decision support systems CDSS on diabetes care management by conducting three separate univariate meta-analyses and one multivariate meta-analysis. CDSS are health information …

Statistical Modeling Of Positive Peer Support On Longitudinal Adolescent Substance Use, Kady Rost

Electronic Theses and Dissertations

To evaluate this study’s research question of ”Does the latent construct of Positive Peer Support (PPS) relate to the construct of Adolescent Substance Use (ASU) over time, controlling for neighborhood safety, race, and sex?”, Structural Equation (SEM) and Latent Growth Curve Modeling (LGCM) were used to investigate trajectories. Secondary longitudinal data from Zimmerman (2014) of 604 students enrolled for four consecutive years in public schools located in Flint, Michigan. In the secondary data resource, students who participated were declared “at risk” by GPA. Significant relationships were found in SEM: Positive Peer Support to Adolescent Substance Use, All Control Variables to …

The Combined Impact Of Continuous And Ordinal Auxiliary Variables On Missing Data Imputation In Sem, Salina Wu Whitaker

Electronic Theses and Dissertations

“Modern” methods of addressing missing data using full-information maximum-likelihood (FIML) have become mainstays in SEM analyses. FIML allows the inclusion of auxiliary variables which carry information that is related to missing values and can reduce bias in parameter estimates. Past research has illustrated the benefits of auxiliary variable inclusion under different missingness conditions (MCAR and MNAR; e.g., Enders, 2008), missingness proportions (e.g., Collins et al., 2001), and although limited, missingness patterns (e.g., Yoo, 2009) in FIML analyses. While past studies have focused on the effects of either continuous or ordinal auxiliary variables, no study has included both types in their …

On The Evolution Equation For Modelling The Covid-19 Pandemic, Jonathan Blackledge

Books/Book chapters

The paper introduces and discusses the evolution equation, and, based exclusively on this equation, considers random walk models for the time series available on the daily confirmed Covid-19 cases for different countries. It is shown that a conventional random walk model is not consistent with the current global pandemic time series data, which exhibits non-ergodic properties. A self-affine random walk field model is investigated, derived from the evolutionary equation for a specified memory function which provides the non-ergodic fields evident in the available Covid-19 data. This is based on using a spectral scaling relationship of the type 1/ωα where ω …

Studying The Relationship Between Financial Risk Aversion And Income With The Jeopardy! Daily Double, Miles Johnson

Mahurin Honors College Capstone Experience/Thesis Projects

It has long been up for debate as to whether there is a link between financial risk aversion and income. This study’s purpose is to, using data from the game show Jeopardy!, investigate this question through analytical research. This study made use of multiple regression analyses in order to examine the relationship between income and risk aversion in Jeopardy! contestants who appeared on the show between January 2019 and October 2020. Specifically, this study looked to isolate the potential impact a contestant’s estimated annual income had on their willingness to bet on the Jeopardy! Daily Double question. It was …

Use Of Research Tradition And Design In Program Evaluation: An Explanatory Mixed Methods Study Of Practitioners’ Methodological Choices, Margaret Schultz Patel

Electronic Theses and Dissertations

The goal of this explanatory sequential mixed method study was to assess whether there were observable trends, associations, or group differences in evaluation methodology by settings and content area in published evaluations from the past ten years (quantitative), to illuminate how evaluation practitioners selected these methodologies (qualitative), and assess how emergent findings from each phase fit together or helped contextualize each other. In this study, methodology was operationalized as research tradition and method was operationalized as research design. For phase one (quantitative), a systematized ten-year review of five peer-reviewed evaluation journals was conducted and coded by journal, research tradition, research …

Assessing The Variations Of Educational Attainment At National And Subnational Levels Using Hierarchical Linear Models, Bingxin Qi

Electronic Theses and Dissertations

Education is a human right, and equal access to education is not only crucial for an individual’s well-being, but also essential for eradicating poverty, ensuring long-term prosperity for all, transforming the society, and achieving sustainable development. Measuring education development, especially the variations of educational attainment, in a timely and accurate manner can help educators, practitioners, scientists, and policymakers compare and evaluate various education indicators at both subnational and national levels. This research presents an approach that combines multi-source and multidimensional data including population distribution, human settlement, and education data to assess and explore educational attainment trajectories at both national and …

A Grounded Theory Inquiry Into The Pedagogical Socialization Of Graduate Students Within Graduate Quantitative Methods Courses, Amanda Kay Thomas

Electronic Theses and Dissertations

Quantitative methods are one of the most highly technical fields of study within social sciences graduate programs. Although classroom pedagogy is an important factor connected to student success within graduate quantitative methods courses little is known on the pedagogical socialization experiences of masters and doctoral students. The purpose of this grounded theory inquiry was to discover graduate students perspectives on their pedagogical socialization experiences and the norms, values and role expectations transmitted during the teaching and learning of quantitative methods. Narrative data was collected from in-depth interviews among a theoretical sample of 31 masters and doctoral students enrolled in introductory, …

Combating The Whitewashing And Male Bias Of The Calculus Curriculum, Sua Cho, Harold Gee Iii, Herbert R. Fynewever

Summer Research

There are so many more mathematicians - even before Newton and Leibniz - that made pioneering contributions to Calculus. The following people are some of the mathematicians of color and women mathematicians who have done significant work in the field of mathematics and in Calculus.

Computational Modeling For Decision-Making Under Climate Change Uncertainty: Reservoir Simulation Game, Julianne Quinn

All ECSTATIC Materials

Almost every decision you make is under uncertainty. Will I need a rain jacket in the afternoon? Will they say yes if I ask them out? Is 1 hour enough time to finish this assignment? Oftentimes, we can use computational modeling to simulate different scenarios of what might happen in the future to inform what decisions are best on average, or what decisions minimize the worst case outcome. For example, you could decide what player to draft for your Fantasy Football team by simulating player performance. In this activity, we will simulate how much water to release from a dam …

The Risk Of Physical Multimorbidity In People With Psychotic Disorders: A Systematic Review And Meta-Analysis, Myanca Rodrigues, Joshua C. Wiener, Saverio Stranges, Bridget L. Ryan, Kelly K. Anderson

Epidemiology and Biostatistics Publications

Background: The occurrence of multiple co-occurring chronic health conditions, known as multimorbidity, is associated with decreases in quality of life for patients and poses unique challenges for healthcare systems. Since people with psychotic disorders have an excess of physical health conditions compared to the general population, they may also be at a higher risk for multimorbidity. We conducted a systematic review and meta-analysis to quantify the prevalence and excess risk of multimorbidity among people with psychotic disorders, relative to those without psychosis.

Methods: We searched the MEDLINE, EMBASE, and PsycINFO databases, and conducted forward and backward citation tracing of included …

Physician Remuneration Schemes, Psychiatric Hospitalizations And Follow-Up Care: Evidence From Blended Fee-For-Service And Capitation Models., Thyna Vu, Kelly K Anderson, Rose Anne Devlin, Nibene H Somé, Sisira Sarma

Epidemiology and Biostatistics Publications

Psychiatric hospitalizations could be reduced if mental illnesses were detected and treated earlier in the primary care setting, leading to the World Health Organization recommendation that mental health services be integrated into primary care. The mental health services provided in primary care settings may vary based on how physicians are incentivized. Little is known about the link between physician remuneration and psychiatric hospitalizations. We contribute to this literature by studying the relationship between physician remuneration and psychiatric hospitalizations in Canada's most populous province, Ontario. Specifically, we study family physicians (FPs) who switched from blended fee-for-service (FFS) to blended capitation remuneration …

Incorporating Animal Movement Into Distance Sampling, R. Glennie, S. T. Buckland, R. Langrock, Tim Gerrodette, Susan Chivers, M. D. Scott

United States Department of Commerce: Staff Publications

Distance sampling is a popular statistical method to estimate the density of wild animal populations. Conventional distance sampling represents animals as fixed points in space that are detected with an unknown probability that depends on the distance between the observer and the animal. Animal movement can cause substantial bias in density estimation. Methods to correct for responsive animal movement exist, but none account for nonresponsive movement independent of the observer. Here, an explicit animal movement model is incorporated into distance sampling, combining distance sampling survey data with animal telemetry data. Detection probability depends on the entire unobserved path the animal …

A Unified Approach For Constructing Confidence Intervals And Hypothesis Tests Using H-Function, Weizhen Wang

Mathematics and Statistics Faculty Publications

We introduce a general method, named the h-function method, to unify the constructions of level-a exact test and 1-a exact confidence interval. Using this method, any confidence interval is improved as follows: i) an approximate interval, including a point estimator, is modified to an exact interval; ii) an exact interval is refined to be an interval that is a subset of the previous one. Two real datasets are used to illustrate the method.