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. Hudgens is a Professor in the Department of Biostatistics at the University of North Carolina at Chapel Hill and is Director of the Biostatistics Core of the UNC Center for AIDS Research. He has extensive experience in collaborative research and statistical methodology development related to studies of infectious diseases and vaccines, with an emphasis on HIV. Dr. Hudgens has co-authored over 100 peer-reviewed papers in leading statistical journals such as Biometrika, Biometrics, JASA, and JRSS-B as well as top-tier biomedical journals such as the New England Journal of Medicine, Lancet, and Nature, and currently serves as an Associate Editor for Biometrics and JASA. He is an elected fellow of the American Statistical Association and has taught multiple graduate level biostatistics courses at UNC. Dr. Hudgens is the principal investigator or co-investigator on several NIH NIAID grants to develop novel statistical methodologies for application to infectious disease studies. He has served as lead statistician on multiple clinical trials sponsored by the NIH and CDC and currently serves on an advisory board to the FDA.

3107C McGavran-Greenberg
Chapel Hill, NC
Fax: 919.966.3804
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.

Chapel Hill, NC
Fax: 919-966-2089
Office Phone: 919-966-7415


Katie Mollan, M.S.

Core Manager / Senior Biostatistician

Katie Mollan
Katie Mollan is a senior biostatistician at the UNC CFAR with over 10 years of HIV research experience. Her collaborative research background spans a breadth of topics in HIV/AIDS, including analysis of large randomized clinical trials, antiretroviral efficacy, psychiatric complications, adherence, drug resistance, pharmacokinetics, HIV testing, and SHIV vaccine development. Ms. Mollan has provided statistical support for grant proposals, HIV network proposals, protocol development, case report forms, database structure, data safety monitoring, statistical analyses, conference presentations, and manuscript preparation. Ms. Mollan has co-authored articles in several medical journals, including Annals of Internal Medicine, Journal of Infectious Diseases, Clinical Infectious Diseases, and the New England Journal of Medicine.

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



Sarah Reifeis, B.S.

Research Assistant

Sarah Reifeis
Sarah Reifeis is a Ph.D. candidate in the biostatistics department at UNC. She received her B.S. in Mathematics from Indiana University. Before coming to UNC she worked for the chemistry department at Indiana University as an undergraduate researcher conducting computational modeling of the HIV-1 capsid. Additionally, she worked for the biology department at Indiana University as a teaching assistant for two years. In her free time she enjoys hiking, scuba diving, and cooking.



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)

CFAR Summer Interns

  • Emma Crenshaw (2018)
  • Jake Mathura (2018)
  • Orlando Ferrer, B.S. (2017)
  • Sumati Sridhar (2017)

Former Biostatistics Graduate Research Assistants [updates circa 2017]

  • Ilana Trumble, M.S. [Doctoral Research]
  • 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, M.S. [Doctoral Research]
  • Joseph Rigdon, Ph.D. [Stanford Med/Quant Sciences Unit]
  • Lu Mao, Ph.D. [University of Wisconsin Madison]
  • Amy Richardson, Ph.D. [Google]


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

-Training and Tutorial Consultation
-Planning and Study Design
-Grant Proposal Support
-Statistical Computation, Derivation, Interpretive Analysis and Publication
-Coordination and Project Management
-Statistical Methods Research and Development








Biostatistics Core Research Group

Meets bi-monthly on the 1st Wednesday of each month from 9:30-11:00am, rotating with the UCHCC Cohort meeting

The UNC CFAR Biostatistics Core hosts meetings among quantitative researchers interested in HIV research throughout the research triangle area, including CFAR members and quantitative researchers from UNC, FHI 360, and RTI. The BCRG, formed in spring 2013, provides opportunities for research synergy and networking, through cross-discipline discussion of quantitative methods in HIV/AIDS research. Meetings have been regularly attended by researchers from a range of quantitative fields, including biostatistics, epidemiology and pharmacokinetic modeling. Past presentation topics have included pharmacokinetic modeling, meta-analysis, measurement of viral load outcomes, and statistical methods for serial limiting dilution assays.

View upcoming and previous meetings here.



Power and Sample Size Boot Camp
September 2014

An Overview of Biostatistics
August 2013


R package for Serial Limiting Dilution Assay Statistics (SLDAssay)

Power Calculator for Repeated Low-Dose Challenge Studies

Brief Statistical Safety Checklist

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

Statistical Checklist