Appendix. Methods

Search Strategies

To update the evidence on screening for colorectal cancer, we performed three separate literature searches using MEDLINE®: one general update from January 1995 to December 2001 and two focused searches for evidence related to barium enema and complications of screening that used search dates from 1966 through December 2001. All searches were limited to "human" subjects.

For the general search, we combined the MeSH® headings "colorectal neoplasms" or "occult blood" or "sigmoidoscopy" or "colonoscopy" with the term "mass screening." This search produced 719 results, of which we retained 19 in the final document.

To identify articles on the use of barium enema, we combined the exploded MeSH® terms "colorectal neoplasms" and "barium sulfate" and "enema," which yielded 621 results. We retained 13 articles in our final data set.

For studies about the complications of screening, we combined the exploded MeSH® terms colonoscopy/ae [Adverse Effects] and sigmoidoscopy/ae [Adverse Effects], intestinal perforation, intraoperative complications, postoperative complications, or gastrointestinal hemorrhage, with a search combining the test names and the keyword "complications." Our search yielded 839 articles, of which we retained 16.

In addition to these searches, we used peer review, hand searching of the bibliographies of included articles and other systematic reviews, as well as articles from the 1996 document, which yielded another 15 references for our final document.

Eligibility Criteria

We developed eligibility criteria to guide decisions about inclusion of articles. In general, we sought to identify and include the highest quality evidence available. The Table shows the criteria for each specific topic.

Table. Eligibility Criteria

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