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Dedication to You

Senior Staff

David T. Gilbertson, PhD

Dr. Gilbertson is the Co-Director of the Chronic Disease Research Group (CDRG).

Prior to becoming Co-Director in 2014, he served as Director of Biostatistics and Epidemiology, since joining CDRG in 2000. His current professional interests include the application of multi-state models to observational epidemiologic analyses, the use of causal inference techniques such as marginal structural models, and other methods of addressing time-varying confounding when using administrative health care claims data.


Kirsten L. Johansen, MD

Dr. Kirsten Johansen joined HCMC as Chief of Nephrology, and is also the Co-Director of CDRG.

Dr. Johansen's research focus is patient-oriented research among patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). In particular, she studies the pathogenesis of debility and evaluates therapeutic strategies to improve functional status in patients on dialysis, addressing these issues through several lines of investigation, including primary data collection through cohort and interventional studies and through use of national data available through the United States Renal Data System (USRDS). Mentoring is also an important focus for Dr. Johansen, and she holds a K24 to support her mentoring efforts.


Allyson Hart, MD

Dr. Hart is a nephrologist at Hennepin County Medical Center, Assistant Professor of Medicine at the University of Minnesota,

and Senior Staff for Kidney at the Scientific Registry of Transplant Recipients. She obtained her MD degree from the University of California, San Francisco, and completed her internal medicine residency at the University of Utah, then completed a fellowship and a Master of Science degree in Clinical Research, with an emphasis on epidemiology, at the University of Minnesota. Her research interests include risk prediction and the use of large data sets to create understandable tools that are useful in clinical settings at the point of care. She is also interested in mixed qualitative and quantitative methods, interdisciplinary team approaches, stakeholder engagement, and research on improving racial and gender disparities in health outcomes.

Ajay K. Israni, MD

Dr. Israni is a nephrologist at Hennepin County Medical Center and Deputy Director of the Scientific Registry of Transplant Recipients.

He is an Associate Professor of Medicine and Adjunct Associate Professor of Epidemiology and Community Health at the University of Minnesota. He has published over 100 manuscripts in the field of nephrology and solid organ transplantation, and has experience seeing thousands of patients for international studies in these fields. Dr. Israni received a prestigious research award from the Robert Wood Johnson Physician Faculty Scholar Program to use administrative datasets and Medicare claims to improve outcomes in solid organ transplantation.

Shuling Li, PhD

Dr. Li is a senior epidemiologist at CDRG. She earned her PhD in epidemiology from the University of Minnesota.

She served as a senior biostatistician for the United States Renal Data System (USRDS) and the Cardiovascular Special Studies Center of the USRDS for 14 years. She has extensive training in the fields of biostatistics and epidemiology, and broad experience in using administrative databases, applying statistical methods, and designing and conducting studies through federal and commercially funded projects. Her research interests include cancer epidemiology, the late effects of cancer therapy, in particular cardiotoxicity and nephrotoxicity of chemotherapy in cancer survivors, and comparative effectiveness research. Her experience includes cancer surveillance and care studies in the clinical areas of solid tumors, acute lymphoid leukemia, multiple myeloma, and primary immune thrombocytopenia.

Suying Li, PhD

Dr. Li is a senior health services researcher at CDRG, specializing in health economics.

She was the lead biostatistician for the National Kidney Foundation’s Kidney Early Evaluation Program (KEEP) Coordinating Center from 2000 through 2011, and served as a co-investigator in the Centers for Disease Control and Prevention’s Chronic Kidney Disease Detection Program from 2006 through 2009. Dr. Li has broad experience in health economics, health service research and policy, and biostatistics methodology. She has authored over 80 publications in peer-reviewed journals, addressing clinical outcomes and Medicare expenditures in dialysis patients, chronic kidney disease risk factors and outcomes in high-risk populations, and diabetes care and related outcomes.

Jiannong Liu, PhD

Dr. Liu is a senior principal biostatistician and Director of Analytics at CDRG. He earned his PhD in biostatistics at the University of Minnesota.

He has served as an investigator and lead biostatistician at CDRG. He served as a co-investigator and lead biostatistician for the United States Renal Data System and as Senior Staff for Biostatistics for the Scientific Registry of Transplant Recipients. Dr. Liu’s research interest is in the development and application of statistical methodology in observational data analyses for surveillance and comparative effectiveness research, emphasizing disease mapping, health care profiling, patient comorbidity burden evaluation, analyses of data with complex relationships, bias correction, and clinical outcome analyses. He has authored more than 90 peer-reviewed journal articles in these related fields.

Jon J. Snyder, PhD

Dr. Snyder serves as the Director of Transplant Epidemiology at CDRG, and is the Director of the Scientific Registry of Transplant Recipients (SRTR).

CDRG’s transplantation division currently operates the SRTR under contract with the Health Resources and Services Administration of the US Department of Health and Human Services. Dr. Snyder oversees CDRG’s research in the areas of organ, eye, and tissue donation and transplantation. His research focuses on data analytics targeted at healing and saving more lives through transplantation, with a particular focus on data used for quality monitoring and quality improvement.

Wendy L. St. Peter, PharmD, FASN, FCCP, FNKF

Dr. St. Peter is a Professor in the College of Pharmacy at the University of Minnesota.

She received her Doctor of Pharmacy degree from the University of Texas Health Science Center, where she also completed a fellowship in adult medicine. She served as a clinical practitioner at Hennepin County Medical Center in Minneapolis for several years where she provided medication therapy management of dialysis and chronic kidney disease (CKD) patients. Her current research interests include prevention and treatment of CKD symptoms, anemia, mineral and bone disease, and the intersection of heart failure, CKD and acute kidney injury.


James B. Wetmore, MD, MS

Dr. Wetmore is the Medical Director for Nephrology Research at CDRG.

His main area of interest is the epidemiologic study of patients with chronic kidney disease and end stage-renal disease, particularly those receiving maintenance dialysis. His particular focus is on the epidemiology of cardiovascular disease and mineral and bone disorders in dialysis patients. He serves as Principal Investigator for several recently undertaken studies using the electronic health records at Hennepin County Medical Center. Dr. Wetmore has authored over 80 peer-reviewed publications and several book chapters. A practicing nephrologist at HCMC seeing inpatients and outpatients, Dr. Wetmore brings real-life clinical experience to his research projects.


Yoon Son Ahn, MS Biostatistician 
Katherine Audette, MS Project Manager
Chris Comstock Full-Stack Software Engineer
Avery Cook, MPH, MSW Project Coordinator 
Tianye Cui, MS Biostatistician
Tonya Eberhard Communications Coordinator
Ryan Follmer IT Director
Beth Forrest Administrator
Anna Gillette Medical Editor
Tingting Gong, MS Biostatistician
Peter Golden Systems Administrator
Haifeng Guo, MS Senior Manager, Biostatistics 
Ahmed Habashy, PMP Senior IT Project Manager
Kayla Horak, MS Biostatistician
Patrick Johnson Senior SQL Database Engineer 
Amy Ketterer Senior Communications Coordinator
Sydney Kletter Senior Administrative Assistant
Iris Kou, MS Biostatistician
Dan Larson SQL Database Engineer 
Grace Lyden, PhD Biostatistician
Jonathan Miller, PhD, MPH Biostatistician
Kimberly Nieman, MS Program Manager
Caitlyn Nystedt, MPH, PMP Program Director, Organ Donation and Transplantation Research
Hilford Ponnie Systems Administrator
Joshua Pyke, PhD IT Manager, DevOps
Nick Roetker, PhD Epidemiologist
Cory Schaffhausen, PhD Human Centered Design Engineer
David Schladt, MS Biostatistician
Mona Shater, MA Marketing & Communications Director
C. Daniel Sheets Senior Systems Administrator 
Eugene Shteyn, MS Senior Software Engineer
Katie Siegert, MPH Project Manager
Bryn Thompson, MPH Senior Project Manager
Xinyue Wang Senior Software Systems Engineer
Tim Weaver, MS Biostatistician
Nicholas Wood, PhD Biostatistician
David Zaun, MS Senior Manager, Biostatistics



The Chronic Disease Research Group (CDRG) is a division of the Hennepin Healthcare Research Institute (EIN 1568208), located in Minneapolis, MN.