In addition, not knowing about the findings of a prior colonoscopy may result in a repeat screening earlier than the recommended 10 years, Sheffield added.
Of course, there are other reasons doctors have patients screened, and billing is one of them, Dr. David Bernstein, a gastroenterologist at North Shore University Hospital in Manhasset, N.Y., said.
"Some are related to changes in the health care system, where the more procedures you do, the more money you make," he said.
There are also competing guidelines that muddy the picture.
The U.S. Preventive Services Task Force and American College of Physicians specify age limits for routine screening for colorectal cancer, but a joint guideline from the American Cancer Society, the U.S. Multi-Society Task Force on Colorectal Cancer and the American College of Radiology does not address age limits for screening, Sheffield said.
"Based on the U.S. Preventive Services Task Force [USPSTF] guidelines, screening colonoscopies performed in adults aged 76 and older are considered inappropriate," she said. "However, other considerations may support the use of screening colonoscopy in some patients, such as those who are at higher risk because of prior polyps."
The study used the USPSTF guidelines as the basis for determining which colonoscopies were inappropriate.
Bernstein, however, doesn't believe age should be the ultimate factor in deciding whether an older patient should have a colonoscopy.
"I don't think age should be the determinate," he said. "I think it should be overall general health. There are people who are 75 or 80 whose life expectancy may be another 20 years, and they should be screened," he said.
The report was published March 11 in the online edition of JAMA Internal Medicine.
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