A Johns Hopkins study found that about one-quarter of U.S. doctors use social media on a daily basis to find medical information, and 6 in 10 doctors say they seek information on social media at least once a week. About half of the physicians polled said they used private, doctor-only social networks to share information. "It's possible that many physicians feel more comfortable with that type of social media instead of a more public space like Twitter or Facebook," study author Dr. Robert Miller said in a statement.