Diagnostic Testing Following Fecal Occult Blood Screening in the Elderly

Reviewers: Li Liu, MD
Source: Journal of the National Cancer Institute, 91:1641-1646, October 1999.

Background

Colorectal cancer is the third most common cancer killer of American men and women. The U.S. Preventive Services Task Force has endorsed annual fecal occult blood test (FOBT) with screening flexible sigmoidoscopy every 5 years in all persons aged 50 years or older. The American College of Physicians has recommended colonoscopy or a flexible sigmoidoscopy with an air-contrast barium enema for patients with any positivity on one or more FOBT cards. Lurie et al. examined patterns of different diagnostic testing procedures following FOBT in elderly (>65 years old) Medicare beneficiaries.

Methods

The Medicare National Claims History System was used to identify 24,246 Americans age 65 or older who received FOBT. For patients with a positive result, the relevant diagnostic testing over the subsequent 8 months was monitored. A determination was made as to the proportion of patients who received an evaluation consistent with the recommendations of the American College of Physicians.

Results

• Ten percent of beneficiaries had positive FOBT and relevant testing in the subsequent 8 months.
• Of those only one third received recommended evaluation of either colonoscopy or flexible sigmoidoscopy with an air-contrast barium enema.
• The remaining received partial colonic evaluation, upper gastrointestinal series, CT/MRI, or upper endoscopy.

Discussion

FOBT is a simple, cost-effective method that identifies a subgroup of the asymptomatic population sufficiently likely to have a clinically important colorectal neoplasm, which justifies more expensive, and invasive diagnostic testing. However, inappropriate follow-up of positive FOBTs may be more costly and less effective than estimated from controlled trials. It is important to educate clinicians, health care payers, as well as the public in order to realize the clinical effectiveness of FOBT screening and maximize its benefit.