Doctors on Facebook risk compromising the doctor-patient relationship because many don't use tight enough privacy settings.
Researchers surveyed the Facebook activities of 405 postgraduate trainee doctors at Rouen University Hospital in France and found that almost three out of four had a Facebook profile. One in four logged on to the site several times a day, and half logged on several times a week.
Almost half believed that the doctor-patient relationship would be changed if patients discovered their doctor held a Facebook account, but three out of four said this would only happen if the patient was able to access their profile.
However, virtually all the doctors - 98 percent - displayed enough personal information for them to be identified, including their real name and birth dates. Ninety-one percent displayed a personal photo. Just over half displayed their current post, while 59 percent provided information on their current university training site.
"Doctors must be aware that comments and pictures posted online may be misinterpreted outside their original context and may not accurately reflect their opinions and real-life behaviour," say the authors. "This information could also become accessible to people that it was not intended for."
Sixty-one percent claimed to have changed at least one of the default privacy settings, but 17 percent couldn't remember whether they had or not.
Only six percent had received a friend request from a patient, four of whom accepted it. But such requests are likely to become more common, suggest the authors.
While 85 percent said they'd automatically refuse a friend request from a patient, one in seven said they'd decide on a case by case basis. The reasons given for accepting a patient as a friend included fear of embarrassing or them if they declined.
"This new interaction (whether it is romantic or not) results in an ethically problematic situation because it is unrelated to direct patient care," say the authors. "Moreover public availability of information on a doctor's private life may threaten the mutual confidence between doctor and patient if the patient accesses information not intended for them."
The reswearch appears in the Journal of Medical Ethics.