X-ray vision
UF radiologist and recent PHHP grad studies how and why doctors order imaging tests
By Elizabeth Behrman
Chris Sistrom/Photo by Jesse S. Jones
After four years as an Army cryptographer during the Vietnam War and three years compiling a radiologic reference guide, Chris Sistrom, Ph.D., M.D., is still sifting through data.
Sistrom, who recently earned his doctorate in health services research from the College of Public Health and Health Professions, spends his days studying why doctors order imaging tests and how many of them are necessary.
With close to 30 years of clinical and research experience under his belt, Sistrom brings a unique perspective to health services research.
Sistrom, an associate professor of radiology at the UF College of Medicine, said his passion for research stems from his love of academia and gaining knowledge to help patients and doctors make rational decisions.
In 2001, Sistrom received a $150,000 grant from General Electric and the Association of University Radiologists, which helped pay for his graduate-level courses at UF.
He took the classes necessary for his degrees in public health and health services research, but he also took classes on subjects that interested him, such as philosophy, computer science, economics and statistics.
“When you delve into it a little bit, and you look into the philosophy of science, you see that underneath many physical facts or laws is doubt and controversy,” Sistrom said.
Sistrom received his undergraduate degree in computer science at the University of Oregon before going to medical school at Oregon Health Sciences University. After completing his residency and a three-year stint as a junior faculty member at the University of Virginia, Sistrom worked in private practice for seven years. He came to UF in 1999.
While in private practice, he spent three years working with Theodore Keats, a professor and emeritus chairman of radiology at the University of Virginia, updating the seventh edition of the reference text Atlas of Radiologic Measurement.
Sistrom helped double the volume of information in the book, adding more about newer techniques such as magnetic resonance imaging and ultrasounds, and expanding subject matter to better cover neurological, cardiovascular, chest and abdomen imaging.
All the data analysis involved with the book kept him interested in academics, and he decided to explore health services research, a mixture of several disciplines, including medical sociology, health economics, management and policy theory.
He wrote his dissertation using experience gained during a 2008 sabbatical at Massachusetts General Hospital, working with architects and administrators of the computerized radiology order entry system, where doctors enter all requests for outpatient X-rays and scans. The doctors get immediate feedback about the appropriateness of the test they are requesting.
Sistrom studied factors that influence decisions made by primary care doctors about whether to order imaging tests. When he applied these factors back to the physicians, his research enabled him to compare doctors’ tendencies to order tests, after considering the ages, sex and illnesses of their patients.
This ability to compare physicians and identify variation in the type and amount of imaging they request can help doctors reduce unnecessary scans.
Sistrom said insurance companies commonly compare doctors’ use of various resources in “efficiency” measures, intended to reward lower-cost doctors. But he said lowering costs is not the primary focus of his research. He just does the analysis and comparisons as truthfully and accurately as possible
“At the end of the day, it’s all about (helping) the doctors,” he said.