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NEW YORK (Reuters Health) - Close to one-quarter of colonoscopies performed on older adults in the U.S. may be uncalled for based on screening guidelines, a new study from Texas suggests.
Researchers found rates of inappropriate testing varied widely by doctor. Some did more than 40 percent of their colonoscopies on patients who were likely too old to benefit or who'd had a recent negative screening test and weren't due for another.
Guidelines from the U.S. Preventive Services Task Force, a government-backed panel, recommend screening for colon cancer - every 10 years, if it's done with colonoscopy - between age 50 and 75.
After that point, "It involves an unnecessary risk with no added benefit for these older patients," said Kristin Sheffield, the new study's lead author from the University of Texas Medical Branch in Galveston.
Those risks include bowel perforation, bleeding and incontinence, as well as the chance of having a false positive test and receiving unnecessary treatment.
Even for screening tests that are universally recommended for middle-aged adults, the balance of benefits and risks eventually points away from screening as people age. Any cancers that are caught might never have shown up during a patient's lifetime if the person is too old or the cancer too slow-growing.
But because there has been so much effort to educate the public about reasons to get screened, the potential harms are often overlooked - and the idea of stopping screening isn't regularly discussed, researchers said.
Sheffield and her colleagues looked at Medicare claims data for all of Texas and found just over 23 percent of colonoscopies performed on people age 70 and older were possibly inappropriate.
For patients age 76 to 85, as many as 39 percent of the tests were uncalled for, the researchers wrote Monday in JAMA Internal Medicine. The rest were likely done for diagnostic purposes.
A MORAL OBLIGATION?
Another study published in the same journal supports the idea that many Americans are so focused on the possible benefits of screening that they don't realize harms are involved as well.
Dr. Alexia Torke from the Indiana University School of Medicine in Indianapolis and her colleagues surveyed 33 adults between age 63 and 91 and found many saw screening as a moral obligation.
Few of the older adults had discussed the possibility of stopping routine screening, such as for breast cancer, with their doctor, and some told the researchers they would distrust or question a doctor who recommended they stop.
"There's very limited data for any cancer test that it leads to any benefit for older adults," said Dr. Mara Schonberg, from Beth Israel Deaconess Medical Center and Harvard Medical School in Boston.
"You want to be doing this thinking it's going to be helping you live longer," she told Reuters Health - especially because the chance of suffering side effects from screening or treatment may be higher among older people.
Schonberg, who wrote a commentary on Torke's study, said time spent unnecessarily screening older adults may take away from conversations that could actually benefit their health - such as about exercise and eating better.
"There's really a strongly held belief that you need to get screened, that it's irresponsible if you don't," said Dr. Steven Woloshin, who has studied attitudes toward screening at the Geisel School of Medicine at Dartmouth in Hanover, New Hampshire.
"There have been all these messages for years about the importance of screening that people have been inundated with, and I think it's really hard to change the message now, even though it's become clear that screening is a double-edged sword," Woloshin, who wasn't involved in the new research, told Reuters Health.
The researchers agreed screening should be an individual decision as people get older, but that everyone should fully understand what they stand to gain - if anything - and what they could lose by getting screened.
For colon cancer in particular, Sheffield recommended elderly people who really want to be screened go with a less-invasive method than colonoscopy, such as fecal occult blood testing.
In another analysis of Medicare beneficiaries undergoing colonoscopy, researchers led by Dr. Gregory Cooper from Case Western Reserve University in Cleveland learned the proportion of procedures using anesthesia - most likely propofol - increased from less than nine percent in 2000 to 35 percent in 2009.
The cost of a procedure using anesthesia is about 20 percent higher than one without it, the researchers noted.
Patients in their study suffered a complication - including perforation or breathing problems - during one in 455 procedures using anesthesia, compared to one in 625 without anesthesia. The researchers said so-called deep sedation may impair patients' airway reflexes and blunt their ability to respond to procedure-related pain.
SOURCE: bit.ly/KEPNSw JAMA Internal Medicine, online March 11, 2013.