Challenges in the Management of Positive Fecal Occult Blood Tests

BACKGROUND: Many patients with a positive fecal occult blood test (FOBT) do not undergo follow-up evaluations. OBJECTIVE: To identify the rate of follow-up colonoscopy following a positive FOBT and determine underlying reasons for lack of follow-up. DESIGN: It is a retrospective chart review. PARTICIPANTS: The subject group consisted of 1,041 adults with positive FOBTs within a large physician group practice from 2004 to 2006. MEASUREMENTS: We collected data on reasons for ordering FOBT, presence of prior colonoscopy, completed evaluations, and results of follow-up tests. We fit a multivariable logistic regression model to identify predictors of undergoing follow-up colonoscopy. RESULTS: Most positive FOBTs were ordered for routine colorectal cancer screening (76%), or evaluation of anemia (13%) or rectal bleeding (7%). Colonoscopy was completed in 62% of cases, with one-third of these procedures identifying a colorectal adenoma (29%) or cancer (4%). Factors associated with higher rates of follow-up colonoscopy included obtaining the FOBT for routine colorectal screening (odds ratio (OR) 1.59, 95% confidence interval (CI) 1.11-2.29) and consultation with gastroenterology (OR 1.99, 95% CI 1.46-2.72). Patients were less likely to undergo colonoscopy if they were older than 80 years old (OR 0.54, 95% CI 0.31-0.92), younger than 50 years old (OR 0.44, 95% CI 0.28-0.70), uninsured (OR 0.50, 95% CI 0.27-0.93), or had undergone colonoscopy within the prior five years (OR 0.32, 95% CI 0.23-0.44). CONCLUSIONS: Clinical decisions and patient factors available at the time of ordering an FOBT impact performance of colonoscopy. Targeting physicians' understanding of the use of this test may improve follow-up and reduce inappropriate use of this test.