Fecal occult blood testing when colonoscopy capacity is limited.
ABSTRACT Fecal occult blood testing (FOBT) can be adapted to a limited colonoscopy capacity by narrowing the age range or extending the screening interval, by using a more specific test or hemoglobin cutoff level for referral to colonoscopy, and by restricting surveillance colonoscopy. Which of these options is most clinically effective and cost-effective has yet to be established.
We used the validated MISCAN-Colon microsimulation model to estimate the number of colonoscopies, costs, and health effects of different screening strategies using guaiac FOBT or fecal immunochemical test (FIT) at various hemoglobin cutoff levels between 50 and 200 ng hemoglobin per mL, different surveillance strategies, and various age ranges. We optimized the allocation of a limited number of colonoscopies on the basis of incremental cost-effectiveness.
When colonoscopy capacity was unlimited, the optimal screening strategy was to administer an annual FIT with a 50 ng/mL hemoglobin cutoff level in individuals aged 45-80 years and to offer colonoscopy surveillance to all individuals with adenomas. When colonoscopy capacity was decreasing, the optimal screening adaptation was to first increase the FIT hemoglobin cutoff value to 200 ng hemoglobin per mL and narrow the age range to 50-75 years, to restrict colonoscopy surveillance, and finally to further decrease the number of screening rounds. FIT screening was always more cost-effective compared with guaiac FOBT. Doubling colonoscopy capacity increased the benefits of FIT screening up to 100%.
FIT should be used at higher hemoglobin cutoff levels when colonoscopy capacity is limited compared with unlimited and is more effective in terms of health outcomes and cost compared with guaiac FOBT at all colonoscopy capacity levels. Increasing the colonoscopy capacity substantially increases the health benefits of FIT screening.
- CancerSpectrum Knowledge Environment 11/2011; 103(23):1726-8. DOI:10.1093/jnci/djr446 · 15.16 Impact Factor
- Gut 02/2012; 61(7):959-60. DOI:10.1136/gutjnl-2011-301810 · 13.32 Impact Factor
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ABSTRACT: Fecal immunochemical tests for hemoglobin are replacing traditional guaiac fecal occult blood tests in population screening programs for many reasons. However, the many available fecal immunochemical test devices use a range of sampling methods, differ with regard to hemoglobin stability, and report hemoglobin concentrations in different ways. The methods for sampling, the mass of feces collected, and the volume and characteristics of the buffer used in the sampling device also vary among fecal immunochemical tests, making comparisons of test performance characteristics difficult. Fecal immunochemical test results may be expressed as the hemoglobin concentration in the sampling device buffer and, sometimes, albeit rarely, as the hemoglobin concentration per mass of feces. The current lack of consistency in units for reporting hemoglobin concentration is particularly problematic because apparently similar hemoglobin concentrations obtained with different devices can lead to very different clinical interpretations. Consistent adoption of an internationally accepted method for reporting results would facilitate comparisons of outcomes from these tests. We propose a simple strategy for reporting fecal hemoglobin concentration that will facilitate the comparison of results between fecal immunochemical test devices and across clinical studies. Such reporting is readily achieved by defining the mass of feces sampled and the volume of sample buffer (with confidence intervals) and expressing results as micrograms of hemoglobin per gram of feces. We propose that manufacturers of fecal immunochemical tests provide this information and that the authors of research articles, guidelines, and policy articles, as well as pathology services and regulatory bodies, adopt this metric when reporting fecal immunochemical test results.CancerSpectrum Knowledge Environment 04/2012; 104(11):810-4. DOI:10.1093/jnci/djs190 · 15.16 Impact Factor