COORDINATED KIDNEY CARE GROUP - Key Persons


A. Roy Shamir

Job Titles:
  • Member of the Professional Staff
Dr. Shamir graduated medical school from Kasturba Medical College, in India. He worked at Father Mullers Medical College (India) prior to relocating to Baltimore, Maryland for his Internal Medicine Residency at Good Samaritan Hospital. After completing his training in nephrology as a fellow at UPMC, Pittsburgh, he worked in private practice in Louisville, Kentucky and Indiana. He moved back to Pittsburgh and joined our practice in 2019. In his spare time, Roy enjoys traveling, ballroom dancing, Latin dancing, international movies and music. He lives in the Mars area with his wife and 2 sons.

Ashley L Clark

Ashley attended Clarion University completing her Associates Degree in Nursing in 2008. She did return to Clarion University receiving her Bachelor's degree in 2011. Ashley worked in the emergency department at Clarion Hospital before completing a Master's degree in Nursing from Chamberlain College of Nursing in 2016. She is certified as a Family Nurse Practitioner by the American Academy of Nurse Practitioners. She has been working as a nurse Practitioner in the Clarion area since 2016.

C. Ross Betts

Job Titles:
  • Member of the Professional Staff
Dr. Betts attended Vanderbilt University in Tennessee earning a bachelor's degree in chemistry. He then attended medical school at the University of Michigan. He completed his Internal Medicine Residency at the University of Minnesota. He fulfilled his Nephrology Fellowship at Washington University. He is certified by the American Board of Internal Medicine in Internal Medicine as well as Nephrology. He and his wife have lived in western Pennsylvania for the past 30 years and they have five children.

David Brooker

Job Titles:
  • Member of the Professional Staff
Dr. Brooker attended college at Wesleyan University in Connecticut and earned a bachelor's degree in chemistry. After working as a research chemist for 3 years at Merck, Sharp & Dohme in Rathway, New Jersey, he attended medical school at Robert Wood Johnson Medical School in Camden, New Jersey. He completed his Internal Medicine Residency and his Nephrology Fellowship at the University of Pennsylvania in Philadelphia, PA. He is certified by the American Board of Internal Medicine in Nephrology. He has been a practicing Nephrologist northwest Pennsylvania since 1997. He has hospital appointments at UPMC Northwest, Clarion Hospital, and Titusville Area Hospital. He lives in the Oil City area and has 4 children.

Smitha Thomas-Mathew

Job Titles:
  • Member of the Professional Staff
Dr. Thomas earned her bachelors in biology from Philadelphia University. She then attended St. George's University School of Medicine where she earned her Doctor of Medicine Degree. She completed her Nephrology Fellowship at Temple University in 2014. She is certified by the ABIM in Internal Medicine and Nephrology. Dr. Thomas completed her internal medical residency at Drexel University/ Hanneman University Hospital in Philadelphia. She joined Northern Tier Nephrology in August 2014. Dr. Thomas lives in Wexford with her husband, daughter and son.