For the study, Sheffield's team also looked at where patients lived and which doctor they went to.
"The likelihood of undergoing a potentially inappropriate colonoscopy depends in part on where patients live and what physician they see," she said. "For some physicians, more than 30 percent of the colonoscopies they performed were potentially inappropriate. This variation suggests that there are some providers who are overusing colonoscopy for screening purposes in older adults."
If older patients strongly prefer to undergo screening, they and their doctor could consider other screening methods that involve less risk, such as a test for blood in the stool, Sheffield said.
But Bernstein noted that a positive fecal blood test leads to a colonoscopy. "I think the best way is a colonoscopy," he said.
Another study in the same journal looked at the complications following a colonoscopy, and found that they happened more often when anesthesia was used.
Specifically, Dr. Gregory Cooper, from the University Hospitals Case Medical Center in Cleveland, and colleagues looked at hospitalizations for spleen ruptures or trauma, colon perforations and pneumonia within 30 days of a colonoscopy with and without anesthesia.
"Although the absolute risk of complications is low, the use of anesthesia services for colonoscopy is associated with a somewhat higher frequency of complications, specifically, aspiration pneumonia," they concluded.
For more information on colon cancer, visit the American Cancer Society.
SOURCES: Kristin Sheffield, Ph.D., assistant professor, University of Texas Medical Branch, Galveston; David Bernstein, M.D., gastroenterologist, North Shore University Hospital, Manhasset, N.Y.; March 11, 2013, JAMA Internal Medicine, online
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