Study Questions Overuse of Colonoscopy in Medicare Patients
MONDAY May 9, 2011 -- Among Medicare patients, colonoscopies are often done more frequently than recommended, a new study finds.
But at the same time, a second study finds that older patients seen at VA hospitals may not always be getting the follow-up colonoscopies they need even when recommendations call for them, such as cases in which blood is detected in the stool.
Both reports were published in the May 9 online edition of the Archives of Internal Medicine.
Colonoscopy -- a test in which a doctor uses a thin flexible tube to view the entire lining of the colon and rectum -- is usually recommended when someone shows possible signs of colon cancer, such as blood in the stool. The American Cancer Society also recommends colonoscopy as a colon cancer screening tool for men and women, beginning at age 50 and at 10-year intervals after that.
"The natural history of polyps going to cancer is incredibly slow -- like 20 years," said Dr. James S. Goodwin, the George & Cynthia Mitchell Distinguished Chair in Geriatric Medicine and director of the Sealy Center on Aging at the University of Texas Medical Branch in Galveston and lead researcher on the first study.
That is why the recommendation, for most people, is a colonoscopy screening every 10 years, he said. "Colonoscopy is not benign. One of every 1,000 people winds up in the hospital because of a complication," Goodwin noted.
For the study, Goodwin's group collected data on 5 percent of Medicare patients from 2000 through 2008. Among these patients, the researchers identified 24,071 who had normal colonoscopies. They then looked at when the next colonoscopy was done.
They found that 46.2 percent of the patients had another colonoscopy within seven years. Out of those, more than 42 percent had no indication of a clear medical need for one so soon after the previous screening.
Getting colonoscopies more often than needed doesn't add a benefit, but rather increases the chances of having a serious complication, Goodwin said.
Repeat colonoscopies were also affected by the patients' age, with 45.6 percent of those aged 75 to 79 and 32.9 percent of those aged 80 and older likely to have a repeat procedure within seven years.
In addition, Goodwin's group found men with other health problems and those seen in high-volume colonoscopy centers were more likely to be tested, as were those in certain parts of the country, particularly in the Mid-Atlantic states.
There are a number of reasons for the overuse of colonoscopy, Goodwin said. "There is the profit motive -- the person recommending the colonoscopy is the person being reimbursed for it," he said.
Also, the benefit of colonoscopy in reducing colon cancer has made some think that more screening is better, he said. Medicare needs to stop reimbursing doctors for too frequent colonoscopies, Goodwin said.
Once the public understands that there are potential harms from colonoscopy, the issue of over-screening will be solved, Goodwin said.
"A lot of endoscopists do ask their patients to return much too early for repeat colonoscopy," said Dr. Durado Brooks, director of prostate & colorectal cancer at the American Cancer Society. "So, we know there is a huge amount of waste going on in the Medicare system. These numbers are probably an understatement of the amount of overuse."
Brooks is also concerned that since a colonoscopy is not a risk-free procedure patients are being put at risk unnecessarily. "You are talking about exposing these elderly patients to a chance for complications with a very little chance of benefit," he said.
Other methods used to screen for colon cancer after 50 include flexible sigmoidoscopy (which examines the lower part of the colon), double-contrast barium enema, and CT (virtual) colonoscopy every five years, along with annual tests for blood in the stool (fecal occult blood tests and others).
In the second study, Dr. Christine E. Kistler, a research assistant professor at the University of North Carolina in Chapel Hill, and her colleagues collected data on 212 patients aged 70 and older who had a positive fecal occult blood test while being seen at VA hospitals.
"A little more than half of people who had a positive fecal occult blood test received follow-up colonoscopy and found serious disease, but half of those who did not receive follow-up colonoscopy died within five years of causes other than colon cancer, " Kistler said. "The patients in the best health were least likely to have more burden than benefit from colon cancer screening."
During seven years of follow-up, 56 percent of these patients had a follow-up colonoscopy. Among these patients, there were 34 with precancerous polyps and six cases of cancer, the researchers noted.
Kistler's team also found 10 percent developed complications related to the procedure or from cancer treatment.
Of the 44 percent who did not have a follow-up colonoscopy, three patients died from colon cancer within five years and there were 43 deaths from other causes in the same period, the researchers found.
"This implies that the appropriate patients are not being targeted for colon cancer screening," Kistler said. "The focus should be on screening and following up screening with the necessary colonoscopy in patients in the best health and avoid screening the patients in the worst health."
These findings supports guidelines that recommend using life expectancy to guide colon cancer screening decisions in older adults and argues against one-size-fits-all interventions that simply aim to increase overall screening and follow-up rates, Kistler said.
All the guidelines say that in most cases if you have a positive fecal occult blood test it should be followed-up with a colonoscopy, Brooks said. However, in older patients who have other serious medical problems no screening for colon cancer should be done, Brooks added.
"You shouldn't start the process if the patient isn't a suitable candidate to finish the process," he said. "It's another example of an inappropriate utilization of screening resources," Brooks said.
The recommendation from the American Cancer Society says that, unless patients have a 10-year life expectancy or they are healthy, one has to weigh the potential benefit of screening against the patient's ability to undergo a colonoscopy and cancer treatment, according to Brooks.
"If the patient is not likely to benefit," Brooks said, "the patient should not be screened."
For more information on colon cancer, visit the American Cancer Society.
Posted: May 2011