Interval between Colonoscopies May be Shorter than Recommended
A study of Medicare enrollees suggests that among those with a negative colonoscopy (a colonoscopy with no abnormal findings), many have a repeat colonoscopy in less than the recommended 10 years. These results were published in the Archives of Internal Medicine.
Cancers of the colon and rectum, sometimes referred to together as colorectal cancer, often begin with the development of an adenomatous polyp. These polyps often take 10 to 15 years to transform into cancer. Because this development phase is so long, screening and early detection can play a role in the prevention of colorectal cancer, as detection and removal of the polyps can prevent the development of the disease.
Screening procedures for colorectal cancer include the fecal occult blood test (FOBT), sigmoidoscopy, colonoscopy, and the double-contrast barium enema. The recommended interval between screening tests varies by the type of test used and the person’s risk of colorectal cancer. After a normal screening colonoscopy in someone at average risk of colorectal cancer, guidelines recommend 10 years before the next colonoscopy. This interval does not apply to people at high risk of colorectal cancer, or to those who experience symptoms of colorectal cancer.
To explore whether patients are being screened with colonoscopy at the recommended interval, researchers evaluated information from a sample of Medicare enrollees at average risk of colorectal cancer. Colonoscopies were classified as a negative screening exam if “screening” was the only indication given for the procedure, and if the procedure did not result in biopsy or polyp removal.
- Among more than 24,000 people who had a negative screening colonoscopy between 2001 and 2003, 24% had a repeat colonoscopy within seven years without a clear reason for the early repeated exam.
- Factors that were linked with an early repeat exam included being male, having a greater number of other health problems, and being seen by a colonoscopist who performs a large number of colonoscopies. The likelihood of an early repeat exam also varied by geographic region.
These results suggest that some patients are being screened with colonoscopy more often than is recommended. The researchers write “Identifying and decreasing overuse of screening colonoscopy should free up resources to increase appropriate colonoscopy in inadequately screened populations.”
Reference: Goodwin JS, Singh A, Reddy N, Riall TS, Kuo Y-F. Overuse of screening colonoscopy in the Medicare population. Archives of Internal Medicine. Early online publication May 9, 2011.