Most physicians paint overly optimistic prognoses for their patients, and many have told lies or withheld information concerning their medical mistakes and financial relationships with drug companies and device manufacturers, according to a national survey conducted by Massachusetts General Hospital researchers. The 2009 survey of nearly 1,900 doctors, published today in the journal Health Affairs, shows that many doctors don’t adhere to the standards of their profession, which have long required doctors to be open and honest with their patients.