The purpose of the CFAR Biostatistics Core is to accelerate successful HIV/AIDS research by direct provision of biostatistical support and by arranging mutually beneficial collaborations between CFAR researchers and statistical scientists.

We provide biostatistical support that is readily available to CFAR investigators and to other CFAR Cores. In addition to making strategic contributions to the CFAR’s scientific dialog, we provide statistical consulting services that range from brief professional consultations to invention of new statistical methods. We collaborate on the framing of hypotheses and on the development of study designs, grant applications, journal articles and presentations, selection of statistical methods, performance of statistical computations and interpretive analyses, and research database management consultation and support.

The Biostatistics Core brings together CFAR investigators and professional biostatisticians who possess specialized expertise needed for CFAR research projects. We promote opportunities for faculty and students in the statistical sciences at UNC to participate in HIV/AIDS-related research and become members of the CFAR. The participating faculty of the Biostatistics Department forms an important component of the Biostatistics Core.

We also promote training opportunities for CFAR investigators who are interested in the application of best statistical methods, and provide training opportunities for students and fellows who are assisting in AIDS-related studies. We recommend that investigators contact the Biostatistics Core in the earliest stage of new research efforts and well in advance of deadlines for grant applications, abstract submissions and protocol development.

Please contact the CFAR Biostatistics Core with new requests by e-mailing us at

Specific Aims

The goal of the Biostatistics Core is to support and enhance AIDS research of the UNC CFAR. We will accomplish these goals with the following Aims:

Aim 1: Provide a broad spectrum of collaborative biostatistical services

Aim 2: Develop, implement, and disseminate innovative statistical methods for HIV/AIDS research

Aim 3: Support priority CFAR initiatives and goals

Aim 4: Promote CFAR research within UNC, foster inter-CFAR collaborations, and support HIV/AIDS research networks

Aim 5: Provide biostatistical training, mentoring, and education

Aim 6: Engage in evaluation and strategic planning

By accomplishing these Aims the Biostatistics Core will continue to provide key statistical support for the UNC CFAR, ensuring sound statistical design, conduct, and analysis of research leading to a deeper understanding of the HIV epidemic.

Michael Hudgens, Ph.D.

Core Director

Michael Hudgens


Dr. Michael Hudgens is a Professor in the Department of Biostatistics at UNC-Chapel Hill and is Director of the Biostatistics Core of the UNC Center for AIDS Research. He has experience in collaborative research and statistical methodology development related to studies of infectious diseases, with emphasis on HIV. Professor Hudgens has co-authored more than 200 peer-reviewed papers in statistical journals such as Biometrics, Biometrika, JASA and JRSS-B as well as biomedical journals such as the Lancet, Nature and New England Journal of Medicine. He currently serves as an Associate Editor for Biometrics, JASA and JRSS-B. He is an elected Fellow of the American Statistical Association and has taught graduate level biostatistics courses at UNC for over ten years.

3107C McGavran-Greenberg
Chapel Hill, NC
Office Phone: 919-966-7253


Stephen R Cole, Ph.D.

Associate Core Director

Stephen Cole
Dr. Cole is a Professor of Epidemiology at UNC with an interest in quantitative epidemiologic methods. He is Associate Director of the Biostatistics Core of the UNC Center for AIDS Research, as well as Director of the Epidemiology and Biostatistics Core of the CFAR Network of Integrated Clinical Systems (CNICS). His research focuses on the use of structural models to explore the causal effect of antiretroviral therapies on HIV disease progression, and direct and indirect causal effects of alcohol intake on HIV acquisition. He is also a member of a Causal Inference Research Group (CIRG) at UNC.


2105E McGavran-Greenberg Hall
Chapel Hill, NC
Office Phone: 919-966-7415


Katie Mollan, M.S.

Core Manager / Senior Biostatistician

Katie Mollan


Katie Mollan, MS, is a Senior Biostatistician and Core Manager at the UNC Center for AIDS Research within the School of Medicine. She has considerable experience in HIV research since 2006, with an emphasis on statistical design and analysis of domestic and international clinical trials. Ms. Mollan has provided statistical support for numerous grant proposals and HIV/AIDS studies, including for the AIDS Clinical Trials Group (ACTG), the HIV Prevention Trials Network (HPTN), and investigator-initiated HIV studies conducted at UNC. Ms. Mollan has co-authored over 45 peer-reviewed articles pertaining to HIV/AIDS, in journals including Annals of Internal Medicine, The Lancet, Journal of Infectious Diseases, Clinical Infectious Diseases, and the New England Journal of Medicine. Her collaborative research background spans a breadth of topics including HIV testing, mental health comorbidities, antiretroviral efficacy, pharmacokinetics, drug resistance, adherence, participant-reported outcomes, vaccine development, and HIV cure. Her research interests include HIV and mental health epidemiology, applied causal inference, and statistical power.

3126 McGavran-Greenberg Hall
Chapel Hill, NC
Office Phone: 919-966-8421


Fei Zou, Ph.D.

Participating Faculty

Dr. Fei Zou
Dr. Zou is a Professor in the Department of Biostatistics and the Department of Genetics at the University of North Carolina at Chapel Hill. Her research interest is in the development of theoretical methodologies appropriate for interpretation of high-dimensional genetics and genomics data. She is highly experienced in gene expression data analysis, genome wide association (GWA) mapping, and next generation sequencing data analysis. She is also experienced in designing clinical trials, and analysis of complex observational data.


4115D McGavran-Greenberg Hall
Chapel Hill, NC
Office Phone: 919-843-4822

Pooja Saha, B.S.P.H.

Research Assistant

Pooja Saha
Pooja Saha is a Ph.D. candidate in the biostatistics department at UNC. She received her B.S.P.H in Biostatistics and B.S. in Mathematics from UNC Chapel Hill as well. Prior to joining CFAR, she worked for UNC School of Dentistry as a graduate research assistant providing statistical support to faculty members and students.




Bonnie Shook-Sa, M.A.S.

Research Assistant

Bonnie Shook-Sa
Bonnie Shook-Sa is a DrPH student in the Biostatistics Department at UNC Chapel Hill.  She received a B.S. in Mathematics and a B.A. in Political Science from Marshall University and a M.A.S. in Applied Statistics from Ohio State University.  Before coming to UNC, Bonnie worked as a Senior Research Statistician at RTI International, where her research focused on sample design, development of sampling weights, and the analysis of complex survey data.



Ann Marie Weideman, M.S.

Research Assistant

Ann Marie Weideman
Ann Marie Weideman is a PhD student in the Biostatistics Department at UNC. She received a B.S. and M.S. in Mathematics from University of Maryland, Baltimore County. Before joining the CFAR, she worked as a post-baccalaureate fellow at the National Institutes of Health (NIH), where her research focused on developing mathematical and statistical models to predict disease progression in patients with multiple sclerosis. During her fellowship at the NIH, she worked as adjunct faculty at Capitol Technology University, where she taught engineering statistics and differential equations. Ann Marie has interests in high performance computing, web-app design, and watercolor painting.


Past Students (2012 Onward)

Former Biostatistics Graduate Research Assistants [updates circa 2019]

  • Sarah Reifeis, B.S. [Doctoral Research, UNC]
  • Ilana Trumble, M.S. [Doctoral Research, UC DENVER]
  • Andrew G. Allmon, B.S. [Doctoral Research, United Therapeutics, UCB]
  • Pedro Baldoni, M.S. [Doctoral Research & Hispanic Community Health Study]
  • Owen Francis, M.S. [Doctoral Research]
  • Brian Barkley, Ph.D [Biostatistical Consultant, Medical College of Wisconsin]
  • Joseph Rigdon, Ph.D. [Stanford Med/Quant Sciences Unit]
  • Lu Mao, Ph.D. [University of Wisconsin Madison]
  • Amy Richardson, Ph.D. [Google]

UNC CFAR Biostatistics Summer Internship

Download the PDF

Past CFAR Summer Interns





HarLeigh Haynie (2019) [Winston-Salem State University]






Emma Crenshaw (2018) [UNC Class of 2019]





Jake Mathura (2018)






Orlando Ferrer, B.S. (2017) [Doctoral Student, Wake Forest]






Sumati Sridhar (2017) [UNC Class of 2019]

The UNC CFAR Biostatistics Core offers a range of services to CFAR investigators, including:

• Study Design and Planning
• Grant Proposal Support
• Statistical Computation, Derivation, Interpretive Analysis and Publication
• Data Carpentry and Visualizations
• Statistical Methods Research and Development
• Database Consultation
• Training and Tutorial Consultation
• Mentoring
• Referrals




Power and Sample Size Boot Camp

An Overview of Biostatistics

Biostatistics Core Research Group


R package for Serial Limiting Dilution Assay Statistics (SLDAssay)

Power Calculator for Repeated Low-Dose Challenge Studies

R Package for Rank-Sum Power Calculation (wmwpow)


Brief Statistical Safety Checklist

Statistical Checklist
“To consult the statistician after an experiment is finished is often merely to ask them to conduct a post mortem examination. They can perhaps say what the experiment died of.” R.A. Fisher