Authors' objectives:

Colorectal cancer screening is now recommended in the general population beginning at age 50 for those at average risk. The most common colorectal cancer screening test in use in the United States is the guaiac based fecal occult blood test (FOBT). Colorectal cancer screening is now covered by Medicare with a reimbursement level of $4.50 for the guaiac test. Immunochemical fecal occult blood tests (IFOBT) have tended to be more expensive and have not yet been widely used in the US. In order to inform coverage and payment decisions related to the use of these tests, this report estimates the cost effectiveness of an immunochemical test with test performance parameters that are equivalent to or better than those associated with the guaiac test. We also report the threshold payment level of the immunochemical test relative to the guaiac test, the level of payment for the immunochemical test that would result in cost-effectiveness equivalent to that of the comparative guaiac test.

Authors' results and conclusions: The cost-effectiveness of the Hemoccult II FOBT ($1,071 per life year gained) is a very favorable level of cost-effectiveness in comparison to other cancer screening modalities. Immunochemical tests, even with costs per test of $28 per test, still have a cost effectiveness ratio of no more than $4,500 per life year saved. At a paymemt level of $28 for IFOBT and $4.50 for Hemoccult II, the incremental cost effectiveness ratio (ICER) for IFOBT is $11,000 per additional life-year saved assuming a specificity of 98% for IFOBT and $21,000 per additional life-year saved assuming a specificity of 95% for IFOBT. The threshold payment level of the IFOBT, with 98% specificity for most test parameters considered, was in the range of $7.00 to $13.00, which is only somewhat higher than the $4.50 of the base case Hemoccult II. However when the IFOBT has specificity of 95%, then the threshold values for most test parameters considered were less than zero dollars. Results for IFOBT are much more favorable if Hemoccult SENSA is assumed to be the base case and especially if IFOBT is assumed to operate at the more favorable specificity value of 98%. A threshold payment level of $28 for IFOBT is exceeded if either or both of the following conditions are met: a) IFOBT is assumed to have the lower specificity value of 95% but much better values of sensitivity for the detection of adenomas than Hemoccult SENSA, or b) IFOBT is assumed to have sensitivity values equal to Hemoccult SENSA but the higher specificity value of 98%. If we assume payment rates of $18 and $27 for IFOBT, then the corresponding threshold payment levels are $10 and $17 for Hemoccult II when IFOBT has 98% specificity and $5 and $14 for Hemoccult SENSA when assuming 95% specificity for IFOBT.

Authors' recommendations: Fecal occult blood tests, either guaiac based or immunochemical based, provide for a very cost effective intervention for reducing colorectal cancer incidence and mortality. If the immunochemical fecal occult blood test maintains the high specificity of Hemoccult II (98%) and increases sensitivity for colorectal cancer to 70% over that of Hemoccult II (40%), then a unit cost level of approximately $13.00 would provide a comparable cost-effectiveness to Hemoccult II at $4.50 per unit cost. If the specificity of the immunochemical fecal occult blood test is assumed to be 95% when the sensitivity for colorectal cancer increases to 70%, then the threshold payment level for IFOBT would actually be lower than the current $4.50. However, further threshold analysis using Hemoccult SENSA as the base case with a sensitivity of 70% for colorectal cancer and specificity of 92.5% indicates that the immunochemical test could achieve a threshold payment level in excess of $28 when the more favorable assumptions about IFOBT are made. Evidence about the relative specificity and sensitivity of IFOBT in comparison to Hemoccult II and Hemoccult SENSA is sparse and highly uncertain. Therefore the scenarios under which the threshold payment level of $28 is exceeded for IFOBT, although potential possible, cannot be considered to be strongly evidence based. If payment level of $18 and $27 are assumed for IFOBT, corresponding threshold payment levels for Hemoccult II would be higher than current payment levels while this would be true for Hemoccult SENSA only if the lower specificity value of 95% is assumed for IFOBT.

Authors' methods: Economic modelling, Economic evaluation

Project Status: Completed

URL for project: http://www.cms.hhs.gov/ncdr/tadetails.aspid=87

Year Published: 2003

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: United States

Organisation Name: Agency for Healthcare Research and Quality

Contact Address: Center for Outcomes and Evidence Technology Assessment Program, 540 Gaither Road, Rockville, MD 20850, USA. Tel: +1 301 427 1610; Fax: +1 301 427 1639;

Contact Name: martin.erlichman@ahrq.hhs.gov

Contact Email: martin.erlichman@ahrq.hhs.gov

Copyright: Agency for Healthcare Research and Quality (AHRQ)