To perform a systematic review of the cost-effectiveness of colorectal cancer screening for the US Preventive Services Task Force.

MEDLINE and the British National Health Service Economic Evaluation Database, January 1993 through September 2001.

Original economic evaluations of colorectal cancer screening in average-risk patients were reviewed. The authors sought studies addressing the incremental cost-effectiveness of different screening strategies compared with no screening, of different screening strategies compared with one another, and of different ages of screening initiation and cessation. Two investigators independently reviewed each abstract, and potentially eligible articles were retrieved. A four-member working group reached consensus regarding final inclusion or exclusion of articles.

One reviewer extracted data into evidence tables. The results were checked by other members and discrepancies resolved by consensus.

Among 180 potential articles identified, 7 were retained in the final analysis. Compared with no screening, cost-effectiveness ratios for screening with any of the commonly considered methods were generally between 10000and 25 000 per life-year saved. No one strategy was consistently found to be the most effective or to have the best incremental cost-effectiveness ratio. Currently available models provided insufficient evidence to determine optimal starting and stopping ages for screening.

Screening for colorectal cancer appears cost-effective compared with no screening, but a single optimal strategy cannot be determined from the currently available data. Additional data regarding adherence with screening over time, complication rates in real-world settings, and colorectal cancer biology are needed. Additional analyses are necessary to determine optimal ages of initiation and cessation.