A study in the March 15 issue of Cancer reports that 5% of Web sites featuring information on breast cancer (found through popular Internet search engines) had inaccuracies or misleading statements. But Web pages discussing complementary and alternative medicine were 15 times more likely to contain mistakes than other Web pages. Moreover, current quality criteria designed to rate online content can't always identify inaccurate medical information.

Texas researchers retrieved 343 Web pages about breast cancer, using five popular consumer search engines. Fifteen quality criteria were used to evaluate each page, including the listing of author credentials and affiliations, the citation of references, and the disclosure of the site's ownership and creation date. Two medically trained reviewers determined the accuracy of the content by comparing information with national guidelines. Among 18 of the 343 Web pages (5.2%), 41 false statements were identified. No one criterion predicted inaccuracy. Although breast cancer information online is generally accurate, the authors conclude, consumers should "maintain a healthy level of skepticism of online health information, consider the reputation of the source, and consult an appropriate clinician before taking action."

Online information about medications is less reliable, according to a report from the Center for Medicine in the Public Interest (CMPI). Google searches about the adverse effects of the cholesterol-lowering drug Crestor (rosuvastatin) and the diabetes drug Avandia (rosiglitazone) found that 43% of results on the first three pages belonged to litigators seeking clients, whereas none belonged to professional medical organizations. This is troubling in light of a 2006 survey by JupiterResearch and the marketing firm iProspect that revealed that most people seeking information online don't search beyond the first three pages of results.

According to the CMPI, 65% of Internet search results are biased or unverified. Web searchers should ask two important questions: "How do I know this information is accurate? Where did this information come from?" The report also notes that the best sites for online medical information include official government or pharmaceutical sites and reputable organizations like the American Heart Association or American Cancer Society. It's available at http://www.cmpi.org.

Carol Potera