Most Americans are aware of websites that rate physicians, and about 30 to 40 percent of site users rely on reviews to choose a physician, according to a research letter published Feb. 19 in JAMA.

In September 2012, a group of University of Michigan researchers used an Internet-based survey tool to ask a sample of Americans about their knowledge and use of online ratings to select a personal physician.

Of the 3,563 adults contacted, 2,137 responded (60 percent). Fifty-two percent were women and 48 percent were men, and 68 percent were white/non-Hispanic. Fifty-nine percent of respondents said physician rating sites were “very important” or “somewhat important,” but they were less of a factor in the decision than other factors, such as recommendations from family and family.

Respondents viewed whether a physician accepted their health insurance as “very important” most often compared with other options. Respondents were more aware of ratings for other goods such as cars, however.

Of those who searched physician ratings, 35 percent said they chose a physician based on positive ratings and 37 percent did not choose a physician because of negative ratings. Among those who did not search physician ratings, 43 percent said they didn’t trust the information.

When asked about the implications of leaving negative feedback about a physician, 34 percent were concerned about their identity being discovered and 26 percent were concerned about repercussions from the physician.

The researchers noted their response rate was only 60 percent and the use of an Internet-based tool may have biased the sample toward younger people.

“Nevertheless, rating sites that treat reviews of physicians like reviews of movies or mechanics may be useful to the public but the implications should be considered because the stakes are higher,” they argued.