Doctoral Theses


  • Daniel H.J. Kang: “Efficient Bayesian Adaptive Designs for Oncology Clinical Trials with Multiple Biomarker Subgroups” (Advisors: Christopher Coffey and Jun “Vivien” Yin)
  • Collin T. Nolte: “What You See is What You Get: A Closer Look at Bias in the Visual World Paradigm” (Advisor: Patrick Breheny)
  • Félix Pabón-Rodríguez: “Bayesian Approaches to Within and Between Host Models for Infectious Disease Processes” (Advisor: Grant Brown)
  • Matthew L. Davis: “Thompson Sampling with Smoothing Splines for Hyperparameter Optimization: A Tuning Algorithm that Doesn’t Need Tuning” (Advisor: Brian J. Smith)
  • Scott H. Koeneman: “Probability Distribution Informed Extensions for Classical Model Selection Methods: Moving Beyond the “Rule of 2″” (Advisor: Joseph Cavanaugh)


  • Nicholas J. Seedorff: “Advancing Flexible Methods for Interpretation and Forecasting of Correlated Data” (Advisor: Grant D. Brown)
    Dr. Seedorff is a Data Scientist at Meta
  • Elliot L. Burghardt: “Agglomerative and Divisive Hierarchical Bayesian Clustering with Methods for Longitudinal and Time-to-Event Data.” (Advisors: Joseph Cavanaugh and Daniel Sewell)
    Elliot Burghardt anticipates completing his M.D. in the Medical Scientist Training Program (MSTP) in spring 2023
  • Monica L. Ahrens:  “Simultaneous Bands for Event Time Percentiles in Cox Models with an Extension to Recurrent Events” (Advisor: Gideon K.D. Zamba)
    Dr. Ahrens is a Research Scientist in the Center for Biostatistics and Health Data Science at Virginia Tech University.
  • Melissa N. Jay: “Bayesian methods for estimation and mediation in disease mapping applications” (Advisor: Jacob Oleson)
    Dr. Jay is an Assistant Professor of Biostatistics, University of Alabama-Birmingham.
  • Zhuangzhuang Liu: “Assessing the Bivariate Time-Varying Association Between Two Binary Variables Measured at Different Times in a Longitudinal Study” (Advisor:  Hyunkeun “Ryan” Cho)
    Dr. Liu is a Senior Statistician at AbbVie, Inc.


  • Alexandra M. Curtis: “Subgroup-Specific Dose Finding Using Bayesian Clustering in Phase I-II Clinical Trials” (Advisor: Brian J. Smith)
    Dr. Curtis is a research scientist at Eli Lilly and Company.
  • Javier E. Flores: “A New Class of Information Criteria for Improved Prediction in the Presence of Training/Validation Data Heterogeneity”  (Advisor: Joseph E. Cavanaugh)
    Dr. Flores is Data Scientist with  Pacific Northwest National Labs in Richland, Washington.
  • Caitlin E. Ward: “Bayesian Methods for Spatio-temporal Epidemic Models to Accurately Capture Complex Dynamics of Disease Spread” (Advisors:  Grant Brown and Jacob J. Oleson)
    Dr. Ward is a postdoctoral fellowship at the University of Calgary.
  • Anna C. Reisetter: “Penalized Linear Mixed Models for Structured Genetic Data” (Advisor:  Patrick Breheny)
    Dr. Reisetter is a research scientist at Eli Lilly and Company.


  • Biyue Dai: “Projection-based Inference and Model Selection for Penalized Regression” (Advisor:  Patrick J. Breheny)
    Dr. Dai is a research scientist at Eli Lilly and Company.
  • Anne E. Welhaven: “Pacing Modification by Incorporation of Lag in Early Phase Designs” (Advisors: Christopher S. Coffey and Eric D. Foster)
    Dr. Welhaven is a biostatistician at AbbVie, Inc.
  • Brandon D. Butcher: “MCMC Diagnostics for Bayesian Additive Regression Trees and Methods for Flexible Modeling of Predictors” (Advisor: Brian J. Smith)
    Dr. Butcher is a statistical scientist at Genentech.


  • Qing Li:  “A Two-stage Pseudo-likelihood Approach to Estimation and Inference for Alternating Recurrent Events Data” (Advisor: Gideon K.D. Zamba)
    Dr. Li is a Senior Statistician at Takeda Pharmaceuticals.
  • Marie V. Ozanne: “Bayesian Compartmental Models for Zoonotic Visceral Leishmaniasis in the Americas” (Advisors: Grant D. Brown and Jacob J. Oleson)
    Dr. Ozanne is assistant professor, Department of Mathematics and Statistics, Mount Holyoke College.
  • Ryan A. Peterson: “Ranked Sparsity: A Regularization Framework for Selecting Features in the Presence of Prior Informational Asymmetry”  (Advisor: Joseph E. Cavanaugh)
    Dr. Peterson is assistant professor, Department of Biostatistics and Informatics, University of Colorado-Denver.


  • Janel K. Barnes: “Regression and Boosting Methods to Inform Precisionized Treatment Rules Using Data from Crossover Studies ” (Advisor: Jeffrey D. Dawson)
    Dr. Barnes is an assistant research scientist in the University of Iowa, Department of Biostatistics, Clinical Trials Statistical Data Management Center.
  • Yiyue Lou: “Principal Stratification: Applications and Extensions in Clinical Trials with Intermediate Variables” (Advisor:  Michael P. Jones)
    Dr. Lou is a senior biostatistician at Vertex Pharmaceuticals.
  • Yaohui Zeng: “Scalable Sprase Machine Learning Methods for Big Data” (Advisor: Patrick J. Breheny)
    Dr. Zeng is a quantitative analyst at Google.
  • Monelle Tamegnon: “Avoiding the Redundant Effect on Regression Analyses of Including an Outcome in the Imputation Model” (Advisors: Michael P. Jones and Gideon K.D. Zamba)
    Dr. Tamegnon is a biostatistician for Johnson and Johnson.
  • Michael Seedorff: “Methods for Testing for Group Differences in Highly Correlated, Nonlinear Eyetracking Data” (Advisors: Jacob J. Oleson and Bob McMurray)
    Dr. Seedorff is a quantitative analyst at Google.
  • Natalie R. Langenfeld: “A Novel Sequential ABC Algorithm with Applications to the Opioid Epidemic Using Compartmental Models” (Advisor:  Grant D. Brown)
    Dr. Langenfeld is a biostatistician for Nestlé Purina North America
  • Benjamin  N. Riedle: “Probabilistic Pairwise Model Comparisons Based on Discrepancy Measures and a Reconceptualization of the p-Value” (Advisors:  Joseph E. Cavanaugh and Andrew A. Neath)
    Dr. Riedle is a research scientist at Eli Lilly and Company.
  • Ryan E. Miller: “Marginal False Discovery Rate Approaches to Inference on Penalized Regression Models”
    (Advisor: Patrick J. Breheny)
    Dr. Miller is an assistant professor at Grinnell College.


  • Hongqian Wu: “Proportional Likelihood Ratio Mixed Model for Longitudinal Discrete Interval Data” (Advisor:  Michael P. Jones)
    Dr. Wu is a Sr. Biostatistician at Novartis Oncology
  • Lixi Yu: “Regularized Efficient  Score Estimation and Testing (RESET) Approach in Low-Dimensional and High-Dimensional GLM” (Advisor: Jian Huang)
    Dr. Yu is a statistician at Phastar.
  • Benjamin E. Deonovic:  “MCMC Sampling Methods for Binary Variables with Application to Haplotype Phasing and Allele Specific Expression” (Advisor: Brian J. Smith)
    Dr. Deonovic is a research scientist at American College Testing (ACT)
  • Keyla Pagán-Rivera:  “Improved Adjustment for Covariate Measurement Error in Radon Studies: Alternatives to Regression Calibration” (Advisor: Brian J. Smith)
    Dr. Pagán-Rivera is a Research Staff Member at the Institute for Defense Analyses.
  • Andrew Ghattas:  “Medical Imaging Segmentation Assessment via Bayesian Approaches to Fusion, Accuracy, and Variablity Estimation with Application to Head and Neck Cancer” (Advisor: Brian J. Smith)
    Dr. Ghattas is a Consumer Behavior Modeler, Bank of America, Charlotte, NC
  • David Zahrieh:  “Bayesian Point Process Modeling to Quantify Excess Risk in Spatial Epidemiology: An Analysis of Stillbirths with a Maternal Contextual Effect” (Advisor:  Jacob J. Oleson)
    Dr. Zahrieh is a research scientist at the Mayo Clinic-Rochester


  • Melissa A. Pugh: “A Bayesian Approach to Detect Time-specific Group Differences Between Nonlinear Temporal Curves” (Advisor: Jacob J. Oleson)
    Dr. Pugh is a Research Scientist (Neuroscience Group), Eli Lilly, Inc.
  • John M. VanBuren:  “Integrating Independent Spatio-Temporal Replications to Assess Population Trends in Disease Spread” (Advisor: Jacob J. Oleson)
    Dr. VanBuren is an Assistant Professor, Department of Pediatrics-Division of Critical Care, University of Utah
  • Wenjing Lu:  “Monotone Spline-Based Nonparametric Estimation of Longitudinal Data with Mixture Distributions” (Advisors: Jeffrey Long and Ying Zhang)
    Dr. Lu is a senior research statistician at AbbVie
  • Fan Tang:  “Structural Time Series Clustering, Modeling and Forecasting in the State-Space Framework” (Advisor: Joseph E. Cavanaugh)
    Dr. Tang is a biostatistician with Genentech
  • Ke Liu: “A Joint Model of an Internal Time-Dependent Covariate and Bivariate Time-To-Event Data in Frequentist Paradigm with an Application to MD STARnet Data” (Advisors: Paul Romitti and Ying Zhang)
    Dr. Liu is Sr. Biostatistician at Gilead Sciences
  • Patrick P. Ten Eyck: “Problems in Generalized Linear Model Selection and Predictive Evaluation For Binary Outcomes” (Advisor: Joseph E. Cavanaugh)
    Dr. Ten Eyck is Assistant Director for Biostatistics and Research Design, Institute for Clinical and Translational Science (ICTS), University of Iowa.


  • Grant D. Brown: “Application of Heterogeneous Computing Techniques to Compartmental Spatiotemporal Epidemic Models” (Advisor: Jacob J. Oleson)
    Dr. Brown is an Assistant Professor in the Department of Biostatistics, University of Iowa.
  • Spencer G. Lourens:  “Bias in Mixtures of Normal Distributions and Joint Modeling of Longitudinal and Time-to-event Data with Monotonic Change Curves” (Advisors: Jeffrey Long and Ying Zhang)
    Dr. Lourens is a Visiting Assistant Professor, Department of Biostatistics, Indiana University
  • Mitchell A. Thomann, “The Flexible Bivariate Continual Reassessment Method ”  (Advisors: Christopher S. Coffey and Eric D. Foster)
    Dr. Thomann is an Research Scientist in Biometrics and Advanced Analytics, Eli Lilly, Inc.


  • Amy M. Johnson: “Modeling Time Series Data with Semi-Reflective Boundaries” (Advisor: Jeffrey D. Dawson)
    Dr. Johnson is an Assistant Professor (Research), Department of Internal Medicine, University of Iowa
  • Knute D. Carter: “Best-Subset Model Selection Based on Multitudinal Assessments of Likelihood Improvements” (Advisor: Joseph E. Cavanaugh)
    Dr. Carter is an Adjunct Assistant Professor of Biostatistics and a Research Scientist, Center for Public Health Statistics, University of Iowa
  • Vivien (Jun) Yin: “Bayesian Statistical Modeling of Epidemics and the Contact Networks that Transmit Them” (Advisor: Brian J. Smith). Dr. Yin is  Assistant Professor of Biostatistics, Mayo Clinic-Rochester


  • Eric D. Foster: “State-Space Time Series Clustering Using Discrepancies Based on the Kullback-Leibler Information and Mahalanobis Distance” (Advisor: Joseph E. Cavanaugh)
    Dr. Foster is an Assistant Professor of Biostatistics, University of Iowa.
  • Shihao Shen: “Statistical Models for RNA Sequencing” (Advisors: Yi Xing and Jian Huang)
    Dr. Shen is Assistant Researcher, Department of Microbiology, Immunology, & Molecular Genetics, UCLA.
  • Elizabeth Dastrup Mills: “Adjusting for Covariates in Zero-Inflated Gamma and Zero-Inflated Log-Normal Models for Semicontinuous Data” (Advisor: Jeffrey D. Dawson)
  • Stephanie A. Kliethermes: “A Bayesian Nonparametric Approach to Modeling Longitudinal Growth Curves with Non-normal Outcomes” (Advisor: Jacob J. Oleson)
    Dr. Kliethermes is the Research Director, American Medical Society of Sports Medicine.
  • Tao Zhang: “Discrepancy-Based Algorithms for Best-Subset Model Selection” (Advisor: Joseph E. Cavanaugh)
    Dr. Zhang is a Senior Biostatistician at Boehringer Ingelheim, China.


  • C. Laura Acion: “Criteria for Generalized Linear Model Selection Based on Kullback’s Symmetric Divergence” (Advisor: Joseph E. Cavanaugh)
    Dr. Acion is an Associate Research Scientist, Department Psychiatry, University of Iowa.
  • Mijin Jang: “Working Correlation Selection in GEE” (Advisor: Jane F. Pendergast)
    Dr. Jang is Assistant Vice President (Sr. Statistical Modeler), JPMorgan Chase, Chicago.
  • Diqiong Xie: “Bias and Variance Estimators of Average Treatment Effect Using Propensity-score Matching” (Advisor: Michael P. Jones)
    Dr. Xie is a biostatistician in the Office of Translational Sciences, Center for Drug Evaluation and Research (CDER), FDA
  • Gang Cheng: “The Nonparametric Least-Squares Method for Estimating Monotone Functions with Interval-Censored observations” (Advisor: Ying Zhang)
    Dr. Cheng is a Senior Biostatistician at Boehringer Ingelheim, China.
  • Dingfeng Jiang: “Concave Selection in Generalized Linear Models” (Advisor: Jian Huang)
    Dr. Jiang is a statistician at AbbVie.
  • Aaron T. Porter: “A Path-Specific Approach to SEIR Modeling” (Advisor: Jacob J. Oleson)
    Dr. Porter is an Assistant Professor in the Department of Applied Mathematics & Statistics, Colorado School of Mines
  • Jingyang Zhang: “Making Diagnosis with Multiple Tests Under No Gold Standard” (Advisors: Kathryn Chaloner and Ying Zhang).
    Dr. Zhang is a Staff Scientist at Fred Hutchinson Cancer Research Center.
  • Ming Yang: “Statistical Models for Count Time Series with Excess Zeros” (Gideon K.D. Zamba and Joseph E. Cavanaugh)
    Dr. Yang is a Research Associate, Center for Biostatistics in AIDS Research, Harvard University.


  • Li Liu: “Grouped Variable Selection in High-Dimensional Partially Linear Additive Cox Model” (Advisor: Jian Huang)
    Dr. Liu is a biostatistiican at Abbvie.
  • Yu-Hui Huang Chang: “Adaptive Designs for Dose Response Studies” (Advisor: Kathryn Chaloner)
    Dr. Chang is a Research Associate, Mayo Clinic Arizona.
  • Lei Hua: “Spline-Based Sieve Semiparametric Generalized Estimating Equation for Panel Count Data” (Advisor: Ying Zhang)
    Dr. Hua is Senior Biostatistician at Vertex Pharmaceuticals, Inc.


  • Patrick J. Breheny: “Regularized Methods for High-dimensional and Bi-level Viable Selection” (Advisor: Jian Huang)
    Dr. Breheny is an Associate Professor of Biostatistics, University of Iowa.
  • JonDavid Sparks: “Model Selection Criteria in the Presence of Missing Data Based on the Kullback Discrepancy” (Advisor: Joseph E. Cavanaugh)
    Dr. Sparks is a statistican at Eli Lillyand Company.
  • Qian Shi: “Bayesian Methods of Evaluation and Use of Surrogate Endpoints in the Single-Trial Settings” (Advisors: M. Kathryn Cowles and Kathryn Chaloner)
    Dr. Shi is an Associate Professor, Department of Health Science Research, Mayo Clinic.
  • Suhong Zhang: “Inference on Association Measure in Copula Model for Bivariate Survival Data with Hybrid Censoring and Application to a HIV Study” (Advisors: Kathryn Chaloner and Ying Zhang)
    Dr. Zhang is a biostatistician in the Cardiac Rhythm Management Division, St. Jude Medical Center, Sylmar, CA.
  • Emine Ozgur Bayman: “Bayesian Hierarchical Models for Multi-Center Clinical Trials: Power and Subgroup” (Advisors: Kathryn Chaloner and M. Kathryn Cowles)
    Dr. Bayman is an Associate Professor of Anesthesia, University of Iowa.
  • Yiyi Chen: “Optimal Adaptive Group Sequential Design for Phase II Clinical Trials: a Bayesian Decision Theoretic Approach” (Advisor: Brian J. Smith)
    Dr. Chen is an Assistant Professor in the Department of Public Health & Preventive Medicine, Oregon Health & Science University.


  • Maria C. B. Mendoza: “Case-deletion Diagnostics for Multipoint Quantitative Trait Locus Linkage Analysis” (Advisors: Michael P. Jones and Trudy Burns)
    Dr. Mendoza is a biostatistician at the National Center for Toxicological Research.
  • Minggen Lu: “Analysis of Panel Count Data Using Monotone Polynomial Splines” (Advisors: Ying Zhang and Jian Huang)
    Dr. Lu is an Associate Professor in the School of Community Health Sciences, University of Nevada-Reno.
  • Zugui Zhang: “Model Selection for Nearly Replicated Data Based on Conceptual Predictive Statistics” (Advisor: Joseph E. Cavanaugh)
    Dr. Zhang is Sr. Biostatistician, Christiana Care Health System, Delaware.
  • Huaming Tan: “Variable Selection and Estimation in the Partially Linear AFT Model” (Advisor: Jian Huang)
    Dr. Tan is Director of Biostatistics at Pfizer.


  • Bongin Yoo: “Estimation and Design Considerations in the Mixed Effects Cox Regression Model” (Advisor: Michael P. Jones)
    Dr. Yoo is Senior Research Biostatistician, Bristol-Myers Squibb.
  • Wei Zhang: “Analysis of Doubly Censored Survival  Data with Applications to GBV-C and HIV Studies” (Advisors: Kathryn Chaloner and Ying Zhang)
    Dr. Zhang is Regional Head of Biometrics and Data Management, Asia/MENA, Boehringer Ingelheim Pharameceutials.
  • Kwang-Youn A. Kim: “Statistical Methods for Detecting Positional Correlation of Expression and Genetic Interactions with eQTL Data” (Advisors: Jian Huang and Val Sheffield)
    Dr. Kim is an Assistant Professor, Feninberg School of Medicine, Northwestern University.


  • Deli Wang: “Robust Estimation of a Two-way Semilinear Model with Applications to Microdata Normalization and Analysis” (Advisor: Jian Huang)
    Dr. Wang is a research statistician at Abbott Laboratories.
  • Xinqun Yang: “The Posterior Probability of Linkage Allowing for Linkage Disequilibrium and a New Estimate of Disequilibrium between a Trait and a Marker ” (Advisors: Jian Huang and Veronica Vieland)
    Dr. Yang is a Senior Manager, Biostatistics at Amgen.
  • Xian-Jin Xie: A Goodness-of-Fit Test for Logistic  Regression Models with Continuous Predictors” (Advisors: William R. Clarke and Jane F. Pendergast)
    Dr. Xie is a Professor in the Department of Clinical Sciences, Simmons Comprehensive Cancer Center, University of Texas-Southwestern.


  • Wenquan Wang: “Estimating and Testing Treatment Effects on Two Binary Endpoints and Association Between Endpoints in Clinical Trials” (William R. Clarke and Robert F. Woolson)
    Dr. Wang is Senior Manager, Biostatistics, Eisai, Inc.


  • Farideh Dehkordi-Vakil: “A Bayesian Method for Estimating Smooth Monotone Functions” (Advisor: Geroge Woodworth)
    Dr. Dehkordi-Vakil is an Associate Professor of Decision Sciences, Western Illinois University.
  • Sheela Kolluri: “A Model for Longitudinal Poisson Count Data with Informative Dropout” (Advisor: Michael P. Jones)
    Dr. Kolluri is a biostatistician, Pfizer-Groton Laboratories.
  • Chandan Saha: “Quantifying the Asymptotic Bias in the Linear Mixed-Effects Model Under Informative Dropout, Drop-In and Other Missing Data Patterns” (Advisor: Michael P. Jones)
    Dr. Saha is Associate Professor of Biostatistics, Indiana University School of Medicine.
  • Brian J. Smith: “A Bayesian Framework for Analyzing Exposure Data from the Iowa Radon Lung Cancer Study” (Advisor: M. Kathryn Cowles)
    Dr. Smith is Professor of Biostatistics, University of Iowa.
  • Jeff M. Allen: “Frequentist Performance of Bayesian Models for Bivariate Longitudinal Data with Two Informative Drop-Out Times” (Advisors: M. Kathryn Cowles and Michael P. Jones)
    Dr. Allen is a statistician at American College Testing (ACT).