MONDAY, Feb. 11 (HealthDay News) -- Just 5 percent of Web pages devoted to breast cancer contain inaccurate information. But pages focused on complementary or alternative medicine are 15 times more likely to make misleading claims and contain other false information, a new study says.

Moreover, standard measures of quality developed to assess the accuracy of Web pages don't really work, said the authors of the study, published in the March 15 issue of the journal Cancer.

"There is no completely reliable Web site, but the bottom line is more information is always better. But consider the source and be cautious in interpreting what you read," said study senior author Dr. Funda Meric-Bernstam, associate professor of surgical oncology at the University of Texas M.D. Anderson Cancer Center in Houston.

"The good news is 95 percent of the information is correct," added Dr. Jay Brooks, chairman of hematology/oncology at Ochsner Health System in Baton Rouge, La. "I have recommended the Internet [to patients] for 10 years. I give them a list." The U.S. National Cancer Institute is high on that list, he said.

According to the study, 44 percent of women recently diagnosed with breast cancer search the Internet for relevant information about the disease. Many visit the Internet before seeing a physician, which means they may be forming opinions and making treatment choices without professional input, the study authors said.

"I have been surprised at how many patients come into the clinic having read something online," Meric-Bernstam said. "Many come in having read about my background, some of them have read my papers, even my lab papers."

Hundreds of quality-rating tools have been developed to help evaluate Web sites. They include such criteria as can you tell who the author is, and is it clear the last time the site was updated.

Still, it's not clear if these methods can sort accurate from inaccurate information, the study authors said.

The researchers looked at 343 breast cancer Web pages found by using five popular search engines, including Google and Yahoo. Each page was evaluated based on 15 quality criteria. The authors then cross-referenced assessments from the 15 criteria with how accurate the pages were.

Overall, there were 41 inaccurate statements on 18 Web pages (5.2 percent), although complementary or alternative medicine pages were 15.6 times more likely to contain false information.

But the quality criteria did not sift the good from the bad Web sites, the researchers said.

"Many of these quality criteria that have been proposed do not allow us to select out inaccurate from accurate Web sites," Meric-Bernstam said.

The Internet can be a useful resource, but relying exclusively on the Web for health information isn't a good idea, the experts said.

"Just because you read something doesn't mean it's right," Brooks said. "I tell my patients, 'You're going to look things up. I can't stop you, but you're paying me to sort through information and give you advice. You're paying for professional expertise.' Knowing something doesn't mean you know how to make it work."

More information

The U.S. National Library of Medicine has a guide to searching the Web.