What’s the best way to get large groups of people screened for colorectal cancer?
Surprisingly it may not be colonoscopy but fecal occult blood testing (FOBT).
A computer model has found annual home testing with a fecal occult blood test, either Hemoccult II® or Hemoccult SENSA®, is more cost-effective than colonoscopy every 10 years to screen people of average risk for colorectal cancer.
The model compared the number of life years saved under several scenarios of costs and compliance with annual testing and follow-up colonoscopies after positive guaiac tests. For the same fixed budget, more people could be screened with an FOBT and more life years saved.
Organized state and federal screening programs are faced with a complex task of choosing the right test that will get the most people screened effectively at the lowest cost. In addition to the cost of the test, program planners have to consider how many patients will follow up with repeat fecal occult list blood testing every year and how many will actually get a colonoscopy if they have a positive test.
Best case scenario: With 100 percent compliance with screening recommendations and follow-up testing, a budget of $1 million dollars would result in a total of 50.9, 52.8, and 40.9 additional life-years for the population of individuals screened with Hemoccult II, Hemoccult SENSA, and colonoscopy, respectively.
The average lifetime cost per person is $1,399 for Hemoccult II, $1,656 for Hemoccult SENSA, and $2,110 for colonoscopy as the primary screening method. Costs included colonoscopy follow-up when tests are positive.
In computing costs, a cost of $23 for FOBT and $699 for colonoscopy was used.
A program using Hemoccult II, with a screening compliance of 60 percent or higher, will yield more total life-years gained than a program using colonoscopy with 100 percent compliance. Hemoccult II will perform better than colonoscopy if at least 75 percent of those with positive guaiac-based fecal occult blood tests undergo diagnostic follow-up colonoscopies.
Only at the lowest level of compliance with testing and follow-up is colonoscopy more effective for broad public screening programs.
Health economist Sujha Subramanian and her team at RTI International concluded,
Although colonoscopy is currently emerging as the most frequently performed colorectal cancer screening test in the United States, in many instances it might not be the optimal choice, especially for programs with fixed budgets. Across a broad population, as opposed to for use in a particular individual, the Hemoccult SENSA test can result in more benefit than colonoscopy. Therefore, colonoscopy should not be automatically considered the appropriate choice.
SOURCE: Subramanian et al.,Health Affairs, published online July 29, 2010. The entire article is available online.
What Does This Mean for Individuals?
This study was designed to look at public screening programs with fixed budgets, not make recommendations for individuals.
Your screening choice, as an individual, may be different.
Colonoscopy allows both screening and removal of any polyps that are found during the procedure. Per test, it is more sensitive for cancer and polyps than FOBT, but may not find all polyps. For average risk patients, it only needs to be repeated every 10 years unless polyps are discovered.
FOBT requires careful compliance to an annual screening schedule and faithful follow-up of all positive tests with a colonoscopy.
People with extra risk because of family or personal history of colorectal cancer or polyps or patients with ulcerative colitis or Crohn’s disease need to be screened with colonoscopy and more often.
Discuss the right test for you with your doctor!