NOW LIST THEIR PRICES:

In a survey of more than 2,100 Americans, researchers found that two-thirds knew that doctor-rating sites exist. And of those surveyed, one-quarter had used the sites in the past year.

Those rates are higher than what's been seen in past studies, said lead researcher Dr. David Hanauer, of the University of Michigan Medical School in Ann Arbor.

"So it looks like there has been increased use over time," Hanauer said.

More important, he added, people who visit the sites use the information to make decisions. In this survey, 35 percent of site users picked a doctor because of a good rating, while 37 percent avoided a doctor with a poor rating, the investigators found.

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