Cost-effectiveness of screening the average-risk population for colorectal cancer.

This article reviews several of the recent models addressing the cost-effectiveness of colorectal cancer screening in the average-risk individual (Table 1). How can clinicians and policy makers use this information for decision making regarding colorectal cancer screening? The cost-effectiveness ratios reported by themselves do not identify cost-effective practices. They must be placed in a decision context that is expressed in one of two forms. In the first form, an explicit threshold or maximum amount that a policy maker is willing to spend is stated (e.g., $40,000 per LY gained, as has been quoted as an acceptable amount for a prevention program). In the second form of decision context, a list of medical practices and their associated cost-effectiveness ratios, also known as a league table (Table 2) is used as a basis for comparison with the practice under evaluation (e.g., colorectal cancer screening). The practice with the lowest cost-effectiveness ratio is the most cost-effective practice on the list. Practices with lower cost-effectiveness ratios are considered cost-effective compared with those with higher ratios. Table 2 lists incremental cost-effectiveness ratios for common medical practices. The models discussed in this article suggested that colorectal cancer screening using annual FOBT, flexible sigmoidoscopy at 3 or 5 years, the combination of FOBT and flexible sigmoidoscopy, barium enema, colonoscopy, and even virtual colonoscopy had incremental cost-effectiveness ratios ranging from $6300 to $92,900 per LY saved with most of the cost-effectiveness ratio ranging from $10,000 to $40,000 per LY saved. These ratios are similar to the cost of another widely accepted practice, breast cancer screening with annual mammography in women age 50 and older ($22,000 per LY gained). Colorectal cancer screening with any of the modalities discussed is considered less cost-effective than screening for hemochromatosis, which has an incremental cost-effectiveness ratio of $3665 per LY saved. Based on these ratios, however, screening for colorectal cancer is considered cost-effective compared with cervical cancer screening in women age 20 and older with pap smear every 3 years, which has an incremental cost-effectiveness ratio of $250,000 per LY gained. The clinician can use these incremental cost-effectiveness ratios to evaluate the risks and benefits of alternative practices for the individual, and the policy maker with a limited health care budget can use these ratios to set priorities for funding based on the costs and the expected gains in life expectancy for colorectal cancer screening and for alternative health care programs.