Our Researchers

Researchers at the Essentia Institute of Rural Health (EIRH) work to advance health care knowledge and make innovations in health care delivery. EIRH researchers are passionate about developing new ways to transform health care. Our researchers include:

Pat Conway

Pat Conway, PhD, MSW

Senior Research Scientist

Dr. Conway conducts research and program evaluation with health and behavioral health programs. These program include: Cancer Prevention Wizard; primary care projects, including the Ely Community Care Team, Behavioral Health Network, and integrated behavioral health; trauma and traumatic brain injury, especially in older people, outcomes of patients who participated in Miller Dwan Rehabilitative Services, and energy-based therapy; the eMERGE II Age-Related Macular Degeneration Project; interdisciplinary teams and intensive care units.

Community health projects Dr. Conway has worked on include the Enhanced Evaluation of the Standing Rock Sioux Tribe’s Men and Women’s Health Screening Days, the Enhanced Evaluation of the Barnes County On the Move Chronic Disease Prevention Program, The Wiconi Ohitika (Strong Life) Youth Suicide Prevention Project Evaluation, and the Spirit Lake Community Assessment.

Her health care workforce projects include the North Dakota IDeA Network for Biomedical Research Excellence Evaluation, the University of Minnesota Native Americans into Medicine Project, and the Increasing Capacity and Enhancing Tribal Innovation Project.


Dr. Conway presents and publishes articles and books in the areas of health, behavioral health, disabilities, violence prevention, rural health, interdisciplinary teaming, social work education, and orphan train riders.


Dr. Conway was a social worker in the fields of child welfare, family violence, mental health, AIDS, health, gerontology, loss and grief, and disabilities. She was a social work educator from 1983 to 2006. Dr. Conway also has conducted training, research, and program evaluations for private non-profit and public agencies. Pat enjoys her family, pets, gardening, reading, knitting, and traveling.


Doctor of Philosophy, University of Texas at Austin, social work
Master of Arts, University of Oklahoma, social work
Bachelor of Arts, University of Oklahoma, social work

Contact Information

Phone: 218-786-2149
Fax: 218-727-8159
Email Pat Conway

Irina Haller

Irina V. Haller, PhD, MS

Research Scientist
Irina V. Haller’s Curriculum Vitae

Dr. Haller is a research scientist at the EIRH and an adjunct assistant professor at the University of Minnesota Medical School, Duluth campus. Her background is in physiology and analytical methodology in biomedical research including design, conduct, monitoring and analysis of clinical trials; population-based studies; utilization of large data sets (such as CMS administrative data) and electronic health records for health services research.

Research Interests

Dr. Haller’s primary research interests are in rural and minority health with emphasis on assessment of vitamin D status and its relation to chronic diseases and health issues in older adults. Currently, Dr. Haller investigates the relationships between age and ethnicity and a response to vitamin D supplementation by food, documentation of vitamin D status in rural and American Indian populations, as well as effects of vitamin D status on cardiovascular health and diabetes in American Indian postmenopausal women.


Prior to joining the University of Minnesota Medical School, Duluth campus and EIRH, Dr. Haller was a research associate in the Laboratory of Neurophysiology of Thermoreception and Heat Exchange and the Department of Physiology at the Petrozavodsk State University Faculty of Medicine, Petrozavodsk, Russian Federation. She serves on the Board of the Duluth Sister Cities International and the Scientific Review Committee for the Duluth Medical Research Institute.

Contact Information

Phone: 218-786-8185
Fax: 218-727-8159
Email Irina Haller

Catherine McCarty

Catherine A. McCarty, PhD, MPH

Research Scientist
Catherine A. McCarty’s Curriculum Vitae

Dr. McCarty conducts research in trauma to support the Level I Trauma Center certification at Essentia Health-St. Mary’s Medical Center. She chairs the Essentia Health Duluth Clinical Ethics Committee. Dr. McCarty also is the associate dean for research at the University of Minnesota Medical School, Duluth campus.


Dr. McCarty was born and raised in Duluth. After completing her PhD, she was the head of the epidemiology research unit in the Department of Ophthalmology at the University of Melbourne, Australia for eight years. During that time, she directed a population-based study of eye disease in Victoria, Australia and collaborated on similar projects in Hyderabad and Chennai, India.

In 2001, Dr. McCarty returned to the U.S. as a senior research scientist at Marshfield Clinic Research Foundation. She served as the principal investigator for the Personalized Medicine Research Project, a population-based biobank with more than 20,000 adult participants and 20 active research projects.

Dr. McCarty has published nearly 400 peer-reviewed manuscripts, earned more than $13 million in research grants, been invited to give many scientific talks, and mentored many students. She has served on the VA Genomic Medicine Program Advisory Committee, the Committee for Scientific Freedom and Responsibility for the American Association for the Advancement of Science, and has served as a consultant to several organizations seeking to start biobanks.


Gwen Sebold Research Award, Marshfield Clinic
Alumni of the Year, University of Minnesota undergraduate college
Silver and Gold Fellow of the Association for Research in Vision and Ophthalmology


Doctor of Philosophy, University of Pittsburgh, epidemiology
Master of Public Health, University of Minnesota, nutrition
Bachelor of Science, University of Minnesota, nutrition

Contact Information

Phone: 218-786-2128
Fax: 218-727-8159
Email Catherine McCarty

Daniel Saman

Daniel M. Saman, DrPH, MPH, CPH

Research Scientist
Daniel M. Saman’s Curriculum Vitae

Dr. Saman's research at the EIRH has focused on improving patients’ health, reducing costs, and improving patients’ experience of care. He is currently the Essentia Health principal investigator of a five-year NHLBI grant-funded study focused on reducing cardiovascular risk among prediabetes patients using a clinical decision support system.

Dr. Saman also leads a study funded by the Essentia Health Duluth Clinic Foundation on determining which factors are associated with an early diagnosis of oral cancer. The study goal is to improve survival among oral cancer patients. He also is the principal investigator of a study funded by the National Cancer Institute aiming to improve cancer screening rates among Essentia Health patients.


During his time at the University of Kentucky, Dr. Saman was involved in diverse and multidisciplinary epidemiological research and collaborated with investigators from the College of Dentistry, the Southeast Center for Agricultural Health and Injury Prevention, the Department of Kentucky Geological Survey, the Center on Drug and Alcohol Research, and the Kentucky Violent Death Reporting System.

Dr. Saman joined the Essentia Institute of Rural Health as an associate research scientist in 2012.


Doctor of Public Health, University of Kentucky College of Public Health, epidemiology
Master of Public Health, University of Kentucky College of Public Health, epidemiology

Contact Information

Phone: 218-786-1754
Fax: 218-727-8159
Email Daniel Saman

Stephen Waring

Stephen C. Waring, DVM, PhD

Research Scientist
Stephen C. Waring’s Curriculum Vitae

Dr. Waring is an epidemiologist and research scientist with the EIRH. His research interests include healthy aging and Alzheimer’s disease, rural health, comparative effectiveness research to inform efficient and effective health care delivery, and translational research that utilizes the wealth of information from genomics and other basic sciences, clinical practice, and community studies to improve population health.

Dr. Waring’s current research includes investigations into healthy aging and cognitive health in rural elderly, including development and evaluation of the utility and effectiveness of clinical decision support tools for dementia screening, diagnosis, and care management. He is also a co-investigator in the Upper Midwest Agricultural Safety and Health Center at the University of Minnesota and professor of pharmacology in the College of Pharmacy, University of Minnesota Duluth.


Dr. Waring has conducted numerous population-based epidemiologic studies in Guam, Olmsted County (Minnesota), Texas, and Central Wisconsin on a broad range of topics. He taught basic, clinical, and advanced epidemiologic methods at Mayo Clinic, Baylor College of Medicine, Texas A&M University, and the University of Texas Health Science Center and School of Public Health.

The Alzheimer’s disease-focused activities Dr. Waring participates in include serving as a member of the board of directors for the Alzheimer’s Association Minnesota-North Dakota Chapter, co-chair of the state of Minnesota ACT on Alzheimer’s Leadership Group for early identification of Alzheimer’s disease, and a member of the Alzheimer’s Association Minnesota-North Dakota Chapter Medical and Scientific Advisory Committee.


Dr. Waring’s work appears in a number of peer-reviewed journals and published abstracts at national and international meetings. He’s an associate editor of the Journal of Agromedicine. Dr. Waring is a Fellow of the American College of Epidemiology in recognition of his significant and sustained contributions to epidemiology.


Doctor of Philosophy, University of Texas School of Public Health, epidemiology with a concentration in neuroscience and biostatistics
Doctor of Veterinary Medicine, Texas A&M University
Master of Science, Texas A&M University, epidemiology
Bachelor of Science, Texas A&M University, zoology

Contact Information

Phone: 218-786-1280
Fax: 218-727-8159
Email Stephen Waring

Daniel Nikcevich

Daniel A. Nikcevich, MD, PhD

Physician Scientist
Daniel A. Nikcevich’s Curriculum Vitae

Dr. Daniel A. Nikcevich is president of Essentia Health-East and has been the principal investigator (PI) of the Duluth Community Clinical Oncology Program (CCOP) since 2005. During his time as PI, CCOP funding has grown, adding components and increasing overall accrual, and it has sustained a strong culture of cancer care, emphasizing the availability of clinical trials as an important standard of care.

Dr. Nikcevich's clinical and scientific interests include the care and management of patients with hematologic malignancies, breast cancer, sarcoma, renal cell carcinoma, and melanoma.

See Dr. Nikcevich’s physician profile.


Dr. Nikcevich serves as the chair of the membership committee for the Alliance, the large oncology cooperative group that resulted from a merger between ACOSOG, CALGB, and NCCTG. He also has served as the vice chair of the executive committee and chair of the membership committee of the North Central Cancer Treatment Group (NCCTG), a national clinical research group sponsored by the National Cancer Institute (NCI).

Contact Information

Phone: 218-786-2628
Email Dr. Nikcevich

Catherine Benziger

Catherine Benziger, MD, MPH

Physician Scientist
Catherine Benziger's Curriculum Vitae

Dr. Benziger earned a medical degree from the University of Minnesota Medical School in Minneapolis, Minnesota. She competed a residency in internal medicine and a fellowship in cardiology at the University of Washington Medical Center in Seattle, Washington. She is certified by the American Board of Internal Medicine in internal medicine. As a medical student, she participated in the National Institutes of Health’s Fogarty International Clinical Research Scholars program, conducting cardiovascular research in Lima, Peru. She also completed a Masters of Public Health in Global Health as part of her cardiology fellowship and has a special interest in cardiovascular disease prevention and population health.

Dr. Benziger is the chair of the Essentia Health Heart and Vascular Scientific Review Committee and is currently the principal investigator for the ADAPTABLE study. She is a member of the Clinical Trials Steering Committee and Population Health Steering Committee. Nationally, she is actively involved in the American Heart Association (AHA) as a member on the Council of Epidemiology Leadership Committee, the Committee on Scientific Sessions Program and the Council of Epidemiology Scientific & Clinical Education Lifelong Learning Committee.

As a community cardiologist, Dr. Benziger works as a general, non-invasive cardiologist in the Heart and Vascular Center in Duluth and maintains a clinical practice that complements her research interests to help guide study development.

See Dr. Benziger's physician profile.

Contact Information

Email Dr. Benziger

Kenneth Dornfeld

Kenneth Dornfeld, MD, PhD

Physician Scientist
Kenneth Dornfeld’s Curriculum Vitae

Dr. Kenneth Dornfeld's research interests involve both clinical and laboratory topics. As a radiation oncologist, he’s interested in improving cancer treatment by increasing the effectiveness of treatment and minimizing side effects. His directs his clinical research efforts towards measuring and minimizing normal tissue damage.

Dr. Dornfeld is part of a group conducting prospective studies using tissue oxygenation as a potential marker for normal tissue injury after radiotherapy. The group also is conducting a longitudinal clinical trial using stereotactic body radiosurgery to minimize the amount of normal tissue irradiated following lumpectomy surgery for early stage breast cancer.

Dr. Dornfeld conducts his laboratory research at the University of Minnesota Duluth. He examines how metabolism influences sensitivity to chemotherapy drugs. Variations in carbon and nitrogen metabolism determine cellular sensitivity to a wide range of chemotherapy agents. Since cancer cells often have altered patterns of carbon and nitrogen use, manipulating metabolism may provide a selective opportunity to enhance the effectiveness of chemotherapy specifically in cancer cells.

See Dr. Dornfeld’s physician profile.

Contact Information

Phone: 218-786-1822
Email Dr. Dornfeld

Bret Friday

Bret E. B. Friday, MD, PhD

Physician Scientist
Bret E.B. Friday’s Curriculum Vitae

Dr. Friday completed his postgraduate training at Mayo Clinic with a fellowship in the Clinical Investigator Training Program in Medical Oncology. He has since been with the Essentia Health Duluth Clinic Section of Hematology/Oncology with outreach to the Virginia and Hibbing clinics.

Dr. Friday has been involved in cancer research through all phases of drug development, including basic science laboratory research, translational research, concept development, protocol development, study community co-chair, and site principal investigator.

Dr. Friday is the associate principal investigator on the federally funded NCI Community Oncology Research Program. He has been an active member of NCCTG and now the Alliance as a member of the concept review committee, neuro-oncology committee, and the board of directors.

As a community oncologist, Dr. Friday maintains a clinical practice that complements his research interests and provides him with important insights to help guide study development. Dr. Friday also serves as the PI of EIRH’s NCORP grant.

See Dr. Friday’s physician profile.

Contact Information

Phone: 218-786-3625
Email Dr. Friday

Michael Mollerus

Michael Emil Mollerus, MD

Physician Scientist
Michael Emil Mollerus’ Curriculum Vitae

Dr. Michael E. Mollerus is cardiac electrophysiologist with Essentia Health since 2001. His research interest focuses on the behavior of cardiac rhythm management devices, such as pacemakers and implantable cardioverter-defibrillators, in the MRI environment, and on how to improve implantable cardioverter-defibrillators sensing algorithms to avoid inappropriate shock therapy. Dr. Mollerus has participated in investigator-initiated as well as industry-sponsored research, and has presented frequently at international scientific sessions and published in peer-reviewed journals.

A graduate of the University of California, San Francisco, Dr. Mollerus completed his internal medicine and cardiology training at the Naval Medical Center in San Diego, and his cardiac electrophysiology training at the University of California, San Diego.

See Dr. Mollerus’ physician profile.

Contact Information

Email Dr. Mollerus

Timothy Rich

Timothy P. Rich, MD

Physician Scientist
Timothy P. Rich’s Curriculum Vitae

Dr. Rich currently serves as chair of the Department of Pulmonary, Critical Care, and Sleep Medicine. His primary affiliation is with the Essentia Health Duluth Clinic, but he also affiliates with and sees patients at Essentia Health clinics across the Northland.

Research area of interest of Dr. Rich largely focus on the treatment of patients with acute respiratory distress syndrome (ARDS) or acute lung injury, which results in a severe, life threatening form of respiratory failure called pulmonary edema (extra fluid in the lungs). Use of the thyroid hormone, Liothyronine (also known as T3) has shown promise. His latest studies involve determining the safety and tolerability of T3 delivery into the lungs of ARDS patients and measure its ability to reduce pulmonary edema.

See Dr. Rich’s physician profile.


For six consecutive years, peer physicians have voted Dr. Rich as one of the Top Doctors in the Duluth-Superior area. He also has been awarded various academic honors during his career.

Contact Information

Phone: 218-786-3993
Email Dr. Rich

Colleen Renier

Colleen Marie Renier, BS

Colleen Marie Renier’s Curriculum Vitae

Colleen is a biostatistician with the EIRH. Her principal research interests include evaluation of existing patient care programs, assessment of pharmacy interventions, and analysis and interpretation of patient reported outcomes (PROs), with a personal focus on health-related quality of life. Colleen has presented and published extensively in these areas.

Since 1988, Ms. Renier has also been a member of the research consortium, headed by University of Minnesota Professor Susan Goodwin Gerberich, PhD, studying the etiology and consequences of injuries sustained by members of agricultural households. This team conducted the groundbreaking Olmsted Agricultural Trauma Study, followed by the Regional Rural Injury Study-I, the model upon which CDC/NIOSH's own surveillance efforts are based, the Regional Rural Injury Study-II, phases I and II, Regional Rural Injury Study-III: Consequences of Agricultural Injuries. Results from the RRIS studies have been presented and published extensively.


Prior to joining EIRH in 1998, she served as the statistical analyst for the Department of Behavioral Sciences at the University of Minnesota School of Medicine, Duluth campus for 17 years.

Colleen is a scientific reviewer for Quality of Life Research and the American Journal of Public Health. She is a member of the International Society for Quality of Life Research and the American Statistical Association.


Colleen is a recipient of the American Public Health Association’s Applied Public Health Statistics, 2014 Achievement Award in Industry.

Contact Information

Phone: 218-786-3834
Toll-free: 800-342-1388, ext. 63834
Mobile: 218-310-6613
Fax: 218-727-8159
Email Colleen Renier

Paul Hitz

Paul Hitz, BS

Research Informatics Manager
Paul Hitz’s Curriculum Vitae

Paul serves as site data manager (SDM) for the Health Care Systems Research Network (HCSRN) formerly known as (HMORN). He came to Duluth from Marshfield Clinic Research Foundation, where he was a research data analyst and SDM for HMORN.

Paul performs programming and analytics tasks on studies in numerous areas including ALS, Breast Cancer Surgery Outcomes, KRAS, Diabetes, and Medical Radiation Induced Cancer. He also works on data infrastructure and performing tasks to support research. He is a co-author on several multi-site journal articles. Paul is committed to helping improve patient health, the healthcare experience, and outcomes.

Paul joined the EIRH as a research informatics analyst in 2012. He was promoted to research informatics supervisor in 2013 and then to research informatics manager in 2016.

Contact Information

Phone: 218-786-1008
Fax: 218-727-8159
Email Paul Hitz

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Get more information about the Essentia Institute of Rural Health and its programs. Call 218-786-3940 or 1-877-710-1094.

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