Fecal occult blood testing when colonoscopy capacity is limited.

BACKGROUND: 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. METHODS: 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. RESULTS: 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%. CONCLUSIONS: 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.

Cost-effectiveness of mass screening for colorectal cancer: choice of fecal occult blood test and screening strategy.

BACKGROUND: Colorectal cancer is a major cause of mortality. This gives high public health priority to mass screening using a noninvasive, fecal occult blood test of asymptomatic individuals. A positive test selects those who should undergo colonoscopy to ensure early detection of colorectal cancer. Guaiac fecal occult blood test has low sensitivity. Automated immunochemical tests that measure the fecal human hemoglobin concentration are more sensitive and can be simplified as a 1- to 3-sample format with optimum cutoff points. OBJECTIVE: The aim was to improve the sensitivity of the test by choosing an accurate format (1- to 3-sample and optimum hemoglobin concentration) while maintaining acceptable specificity and avoiding alteration of the screening program in terms of quality of life and economic outputs. METHODS: We used a Markov model to estimate the cost-effectiveness of a screening program for a population of 100,000 asymptomatic individuals by use of immunological fecal tests with different cutoffs, leading to different sensitivity/specificity ratios, and to compare its incremental cost-effectiveness ratio compared with the guaiac fecal test program. RESULTS: The results suggest that a 3-sample immunological test with 50 ng/mL as a positive cutoff is cost-effective. It provides more asymptomatic cancer detection without significantly increasing normal colonoscopies. CONCLUSION: This format should be prospectively evaluated in mass screening.

Colorectal cancer screening comparing no screening, immunochemical and guaiac fecal occult blood tests: a cost-effectiveness analysis.

Comparability of cost-effectiveness of colorectal cancer (CRC) screening strategies is limited if heterogeneous study data are combined. We analyzed prospective empirical data from a randomized-controlled trial to compare cost-effectiveness of screening with either one round of immunochemical fecal occult blood testing (I-FOBT; OC-Sensor®), one round of guaiac FOBT (G-FOBT; Hemoccult-II®) or no screening in Dutch aged 50 to 75 years, completed with cancer registry and literature data, from a third-party payer perspective in a Markov model with first- and second-order Monte Carlo simulation. Costs were measured in Euros (€), effects in life-years gained, and both were discounted with 3%. Uncertainty surrounding important parameters was analyzed. I-FOBT dominated the alternatives: after one round of I-FOBT screening, a hypothetical person would on average gain 0.003 life-years and save the health care system €27 compared with G-FOBT and 0.003 life years and €72 compared with no screening. Overall, in 4,460,265 Dutch aged 50-75 years, after one round I-FOBT screening, 13,400 life-years and €320 million would have been saved compared with no screening. I-FOBT also dominated in sensitivity analyses, varying uncertainty surrounding important effect and cost parameters. CRC screening with I-FOBT dominated G-FOBT and no screening with or without accounting for uncertainty.

A comparison of three stool tests for colorectal cancer screening.

The annual guaiac or immunochemical fecal occult blood test (FOBT) is one of the five colorectal cancer (CRC) screening regimens recommended by the American Cancer Society (Smith, Cokkinides, & Eyre, 2005). Stool-based deoxyribonucleic acid (DNA) testing for CRC is considered a promising technology (Smith, Cokkinides, & Eyre, 2003). Numerous features of three noninvasive stool tests for CRC are compared.

From guaiac to immune fecal occult blood tests: the emergence of technology in colorectal cancer screening.

Colorectal cancer is the second leading cause of cancer deaths in the United States for both men and women. Colorectal cancer screening is an important means for reducing morbidity and mortality. The American Cancer Society recommends five different screening regimens for adults of average risk, age 50 years and older. The optimal effectiveness of a screening program is dependent on the accuracy of the screening test used. An accurate screening test would have high sensitivity (positive) when an adenomatous polyp or cancer is present and high specificity (negative) in their absence. In April 2002, the American Cancer Society Colorectal Cancer Advisory Group concluded that the immunochemical fecal occult blood test has some advantages that merit revision of their guideline statement for fecal occult blood testing, to include the immunochemical fecal occult blood test. The advantages cited were the possibility of improved sensitivity and specificity and the lack of required dietary restrictions, which make it a more patient-friendly test. Several types of immunochemical fecal occult blood tests are discussed in this article, including their advantages and disadvantages compared with those of the traditional guaiac fecal occult blood testing.

Use of pharmacoeconomics in prescribing research. Part 3: Cost-effectiveness analysis--a technique for decision-making at the margin.

This is the third Research Note addressing pharmacoeconomics in prescribing research, reflecting the increasing use of economic evaluation in drug purchasing decisions in a variety of settings. In this segment we provide an overview of the theoretical basis, practical application and methodological limitations of cost-effectiveness analysis (CEA).