Most internet users start at a general search engine when researching health and medical advice online - and three-quarters of internet users who look online for such advice do not consistently check the source and date of the information they find, according to a Pew Internet Project report titled "Online Health Search 2006" (via Micro Persuasion).

"Search engines are the first stop for two-thirds of internet users with a health question and it turns out the search is often on behalf of someone else," said Pew Associate Director Susannah Fox, who authored the report (pdf).

A mere 15 percent of health-information seekers (some 10 percentage points fewer than in 2006) say they "always" check the source and date of the health information they find online; another 10 percent (15 percentage points fewer than in 2006) say they do so "most of the time," according to Pew. Fully three-quarters of health seekers, compared with 50 percent last year, say they check the source and date "only sometimes," "hardly ever," or "never." In other words, about 85 million Americans gather health advice online without consistently examining the quality indicators of the information they find.

Some 80 percent of U.S. internet users, or about 113 million adults, have searched for information on at least one of 17 health topics. Certain groups are the most likely to have sought health information online: women, internet users younger than 65, college graduates, those with more online experience, and those with broadband access at home.

Some 66 percent of health-information seekers began their last online health inquiry at a search engine; 27 percent began at a health-related website.

Nearly half - 48 percent - of health-information seekers say their quest for information was undertaken on behalf of someone else, not themselves. Another 8 percent say the search was on behalf of someone else and to answer their own health questions; 36 percent say their last search was in relation to their own health or medical situation.

More than half - 53 percent - report that their most recent health-information session had some kind of impact on how they take care of themselves or care for someone else: 74 percent say they felt reassured that they could make appropriate healthcare decisions after their last search; a majority say they felt confident to raise new questions with their doctor, felt relieved or comforted by the information they found online, or were eager to share their new knowledge with others.