Physicians who choose to partner with DaVita have direct access to some of the world’s leading clinical experts in various areas of kidney care. DaVita’s clinical leadership team—including the Office of the Chief Medical Officer (OCMO), group medical directors and our physician partners—works together to identify, shape and drive the patient programs that are implemented in our more than 2,000 dialysis centers.
When determining our approach to care at DaVita, our clinical leadership team continuously innovates new and improved ways to address patients’ kidney care issues and their health-related quality of life.
Office of the Chief Medical Officer
DaVita’s Office of the Chief Medical Officer is composed of a group of experienced nephrologists committed to providing value for patients, delivering high-quality care, improving clinical outcomes and being responsible stewards of resources. OCMO focuses on the needs of DaVita’s medical directors and physician partners by strengthening clinical and operational partnerships and developing new tools and resources to help tackle the daily challenges in kidney care.
Allen R. Nissenson, MD, FACP, FASN, FNKF | Chief Medical Officer | @DrNissenson
Prolific author and renowned authority on kidney disease, Allen R. Nissenson, M.D., is emeritus professor of medicine at the David Geffen School of Medicine at UCLA, where he has served as director of the dialysis program and associate dean. Dr. Nissenson is also co-chair of the Kidney Care Partners Quality Initiative. He is a former president of the Renal Physicians Association (RPA) and served on the RPA Board of Directors as a special advisor to the president. Dr. Nissenson is a past president of the Southern California End-Stage Renal Disease Network. He is the author of more than 650 scientific papers and the editor of two dialysis textbooks, both in their 4th editions. Read Allen’s Blog >>
Mahesh Krishnan, MD, MPH, MBA, FASN | International Chief Medical Officer and Group Vice President of Research and Development
Before joining DaVita Kidney Care, Mahesh Krishnan, M.D., served as medical director and global development leader for Epogen, where he played a key role in discussions with the FDA and the Centers for Medicare and Medicaid Services. He also assisted as executive director of medical policy for Amgen, and had a private practice in Virginia for nearly five years. He currently serves on the editorial board of Nephrology News and Issues and his writing has been published many times in renal care and research publications around the world. Dr. Krishnan earned his medical degree from Thomas Jefferson University, and holds a master's degree in Public Health from Johns Hopkins University and an MBA in Medical Services Management from the Johns Hopkins Carey School of Business.
Stephen McMurray, MD, FACP | Vice President, Clinical Integrated Care Management Services
Stephen D. McMurray, M.D., began his career at Indiana Medical Consultants, a 35-physician multi-specialty group in Fort Wayne, Indiana. In 1996, Dr. McMurray became a founding member of Renal Care Group (RCG) and later a formal board member. He is a former Renal Physicians Association Board member, and received his medical degree from the Indiana University School of Medicine.
Mark Kaplan, MD | Vice President, Medical Affairs
Mark R. Kaplan, M.D., previously practiced nephrology in Nashville, Tennessee, where he launched and developed the practice's clinical research program. He served as the vice president of clinical research at Renal Care Group and Fresenius Medical Care, and was chief medical officer at DSI Renal, Inc. before joining DaVita Kidney Care. Dr. Kaplan earned his medical degree at Vanderbilt University, and then completed a year as chief resident in internal medicine at the Nashville Veterans Affairs Medical Center, and a clinical and research fellowship in nephrology and hypertension at Harvard University Medical School's Brigham and Women's Hospital in Boston.
Robert Provenzano, MD, FACP, FASN | Vice President, Medical Affairs | @DrBobPro
Robert Provenzano, M.D., is a clinical professor of medicine at Wayne State University School of Medicine in Detroit, where he earned his medical degree. He completed his fellowship training at Henry Ford Hospital and served as the chief of the section of nephrology, hypertension and transplantation and director of nephrology research at St. John Hospital and Medical Center in Detroit. Dr. Provenzano is past president of the Renal Physicians Association and Chair of the National Kidney Foundation (NKF) of Michigan. He recently stepped down as the CEO of St. Clair Specialty Physicians, PC, a multistate nephrology practice. He has published extensively on kidney care business models and currently oversees Nephrology Practice Solutions (NPS), a national kidney care practice management solution affiliated with DaVita. He also serves as the medical director of DaVita hospital services, which supports more than 1,000 hospital acute dialysis programs.
David B. Van Wyck, MD | Vice President, Clinical Support Services
David B. Van Wyck, M.D., is emeritus professor of medicine and surgery at the University of Arizona College of Medicine, where he received his medical degree. He was also past co-chair of the National Kidney Foundation Kidney Disease Outcomes Quality Initiative (NKF-KDOQI) Anemia Workgroup. Dr. Van Wyck has written or contributed to publications on basic iron metabolism and reticuloendothelial function, and on clinical aspects of iron and anemia in patients with chronic kidney disease.
John Robertson, MD | Vice President, Clinical Support Services
John A. Robertson, M.D., is founder and partner of Nephrology Associates Medical Group, Inc., the third largest nephrology group in the state of California. He has been a member of DaVita Kidney Care's Physician Council for several years, is a medical director for the DaVita Kidney Care—SCAN CMS ESRD Demonstration Project and is affiliated with Apex Research of Riverside, a private practice participating in clinical trials.
Robert Merrell, MD, FACP | Vice President, Clinical Risk Support
Robert Merrell, M.D., has been a private-practice nephrologist for 25 years, serving patients at Kidney Specialists of Southern Nevada for most of that time. He has served as medical director at several DaVita Kidney Care centers over the years and now oversees DaVita’s Siena Henderson Dialysis Center in Henderson, Nevada. He is board-certified in nephrology and internal medicine, a fellow in the American College of Physicians, and received his medical degree from the University of Oklahoma Health Sciences Center, Department of Medicine.
Martin Schreiber, MD | Vice President, Clinical Affairs – Home Dialysis
Martin Schreiber, M.D., came to DaVita Kidney Care with nearly 40 years of experience in nephrology. Before this this role, he worked primarily with Cleveland Clinic and held a number of key positions there, including Member Board of Governors, Chairman of the Department of Nephrology and Hypertension and the Director of Home Dialysis. Additionally, he is an active educator and international lecturer, with previous editorial responsibilities with the Journal of the American Society of Nephrology, American Journal of Kidney Disease and Peritoneal Dialysis International. Dr. Schreiber received his medical degree through Wake Forest University School of Medicine.
Steven M. Brunelli, M.D., MSCE | Vice President and Medical Director of Health Economics and Outcomes Research
Prior to joining DaVita Clinical Research, Steven M. Brunelli, M.D., was a faculty member at Harvard Medical School and the Brigham and Women’s Hospital, where he directed an active clinical research group that focused on chronic kidney disease, pharmacoepidemiology and pharmacoeconomics, dialysis outcomes epidemiology and the hospital’s dialysis service. He also served on the American Society of Nephrology’s Dialysis Advisory Group and its Comparative Effectiveness Taskforce. Dr. Brunelli has published more than 90 peer reviewed publications, and serves on editorial boards at the Journal of the American Society of Nephrology and the American Journal of Kidney Diseases. He completed medical school at the University of Pennsylvania, earned a Master of Science degree in Clinical Epidemiology and served as faculty at University of Pennsylvania.
Lorne Holland, M.D. | Chief Laboratory Officer, DaVita Labs
Prior to joining DaVita Labs, Lorne Holland, M.D., served as a medical director for the west region of Quest Diagnostics. Before that, he held medical directorship positions at PathGroup, a regional reference laboratory providing clinical and anatomic pathology services, and at the University of Colorado Hospital. He earned his medical degree at the University of Illinois and MBA from Amberton University.
John R. Wigneswaran, M.D. | Vice President, Clinical Affairs – Hospital Services | @doctorWIG
John R. Wigneswaran, M.D., received his medical degree from Tufts University School of Medicine, renal fellowship from Cornell University and MBA from the Massachusetts Institute of Technology. Before joining DaVita Kidney Care, Dr. Wigneswaran served as Medical Director in Medical Affairs for Johnson and Johnson, Chief Medical Officer for CHF Solutions, Inc./Gambro and Vice President of Market Development at Fresenius Medical Care. He was certified by both the Boards of Internal Medicine and Nephrology and is a member of the American Society of Nephrology. In addition, Dr. Wigneswaran founded Nephroceuticals, an organization focused on improving nutritional health of patients with chronic diseases.
For more insight from OCMO, visit our Kidney Care Physician Video Library, featuring more than 50 videos on topics ranging from clinical initiatives and integrated care to home dialysis and medical director resources.
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