MONDAY, March 11 (HealthDay News) -- Almost a quarter of the colonoscopies done on seniors each year may not be necessary, a new study by University of Texas researchers suggests.
Colonoscopy is the "gold standard" screening for colorectal cancer, but guidelines from different groups vary, patients may pressure doctors to get the test even though they don't need it and some doctors are unaware of the guidelines, the researchers said in explaining their findings.
The team looked at Medicare records in Texas, along with a nationwide sampling of screening colonoscopies that were done on those aged 70 and older in 2008-2009. Using age-based screening guidelines or results from an earlier screening, 23.4 percent of the colonoscopies were what they called potentially inappropriate.
"This is important information for patients and their providers, who should be aware of screening guidelines and the risks of colonoscopy screening in older patients," said lead researcher Kristin Sheffield, an assistant professor at the university's Medical Branch in Galveston.
"We hope that there will be efforts to align screening practices with current guidelines, perhaps through better communication between gastroenterologists and primary care physicians, and public education campaigns to correct misperceptions by patients and physicians regarding cancer screening," she added.
Generally, a screening colonoscopy, as opposed to a diagnostic colonoscopy, is done after age 50, and if no polyps are found, is not done again for another 10 years. If polyps are found or there is a family history of colon cancer, then the follow-up screenings are recommended more frequently.
Doctors may not follow the guidelines for a number of reasons, Sheffield said.
"There may be a request from a patient or referring physician; poor communication between gastroenterologists and primary care physicians; or misperceptions on the part of the patient or physician regarding the benefits of cancer screening, particularly in older age groups," she said.
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.
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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