Each year an estimated 12 million Americans get the wrong diagnosis from their doctor--a medical problem is seen as something else, missed entirely or identified late. Most of the diagnostic errors are not about rare diseases, and in about one third of these cases the results of the error are serious, even fatal. Neurologist Dr. David Newman-Toker joins us to talk about the new Johns Hopkins Center for Diagnostic Excellence at the Armstrong Institute for Patient Safety and Quality. They aim to improve how diagnoses are made. Dr. Newman-Toker, who heads the center, also shares actions a patient can take to improve their odds.