A significant number of screening colonoscopies are being carried out more often than the recommended intervals, while older individuals treated at Veteran Affairs centers, where positive fecal blood tests merited follow-up colonoscopies, were not getting them, or they caused problems when colonoscopies were performed, researchers from the University of Texas wrote in Archives of Internal Medicine.

In one article, the authors explain that colonoscopies for the detection of colorectal cancer may be used too often as a screening tool, which raises the risk of adverse events and not enough benefit, money being wasted, and the overuse of limited medical equipment.

Clinical guidelines recommend that a patient who undergoes an initial screening, should not have another one for ten years if no signs of cancer were found.

The authors wrote:

“Identifying and decreasing overuse of screening colonoscopy should free up resources to increase appropriate colonoscopy in inadequately screened populations.”

James S. Goodwin, M.D., and team examined a national sample containing 5% of Medicare beneficiaries from 2000 to the end of 2008. Patients at average colon cancer risk were identified – they had received their first screening colonoscopy between 2001 and 2003. 24,071 of them had no signs of cancer (negative screening examination result). They calculated how long it took, on average, until the second screening took place.

23.5% of them had a second screening within 7 years, with no clear explanation for such an early repeat screening. Second screening occurred more often among older patients – 45.6% of those aged 75 and 79 years, and 32.9% among those aged 80+. The authors added that males, individuals with multiple health conditions, patients screened in high-volume colonoscopy settings, as well as people who lived in certain geographic areas, had a greater likelihood of being tested.

Colonoscopy screening rates need to be monitored more carefully, the authors wrote, so that resources are focused on those who really need it and can benefit the most.

The authors wrote:

“Early repeated colonoscopies without clear indication compose a substantial proportion of the present endoscopist workload and also represents substantial Medicare expenditures. Given the increasing public interest in and ownership of cancer screening, public information campaigns that emphasize both the necessity for colorectal cancer screening as well as the dangers of overuse may prove beneficial in reducing overuse.”

In a separate article, Christine E. Kistler, M.D., M.A.Sc. and team from the University of North Carolina at Chapel Hill revealed that a significant number of individuals who should have undergone colonoscopies did not, while others who did, experienced adverse events.

They gathered data on 212 patients who were being treated through the Veterans Affairs centers, and who were aged 70+ – they had had a positive result on a FOBT (fecal occult blood test). They were followed up for seven years to find out whether other interventions had taken place and what their outcomes were.

56% of them received a follow-up colonoscopy, resulting in 34 positive results for significant adenomas, as well as six cases of cancer. 10% of them developed complications from the screening or from cancer therapy. 44% of them had no follow-up colonoscopy, three of them died of colorectal cancer within five years, while 43% died of other causes. The researchers also worked out the relative benefits versus the burdens of the procedure against the patients’ life expectancies.

Determining which patients are good FOBT candidates needs to be improved, the authors stressed.

They wrote:

“As with all screening tests, FOBT does not benefit most patients because most do not have cancer or significant adenomas.”

Even so, 15.6% of them had cancer or significant adenomas detected by the test and were treated effectively. This suggests that a sizeable minority received net benefit from current practices.

The authors added that patients with the best life expectancies benefited the most from the test.

They concluded:

“Our study supports guidelines that recommend using life expectancy to guide colorectal 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.”

“Long-term Outcomes Following Positive Fecal Occult Blood Test Results in Older Adults”
Christine E. Kistler, MD, MASc; Katharine A. Kirby, MS; Delia Lee, BS; Michele A. Casadei, BS; Louise C. Walter, MD
Arch Intern Med. Published online May 9, 2011. doi:10.1001/archinternmed.2011.206

“Overuse of Screening Colonoscopy in the Medicare Population”
James S. Goodwin, MD; Amanpal Singh, MD, MS; Nischita Reddy, MD; Taylor S. Riall, MD, PhD; Yong-Fang Kuo, PhD
Arch Intern Med. Published online May 9, 2011. doi:10.1001/archinternmed.2011.212

Written by Christian Nordqvist