“4368. That Patient is not like to recover, that makes the Doctor his Heir.”

Attempting to quell rumors of Soviet leader Chernenko's ill health, as quoted in "Visiting Soviet Doctor Changes His Statement" in The New York Times (10 February 1985) http://select.nytimes.com/gst/abstract.html?res=F70F14F63C5D0C738DDDAB0894DD484D81.

Source: War and Peace

A Battle For Life (July 1958)

The Other World (1657)
Context: The most competent physician of our world advises the patient to listen to an ignorant doctor who the patient thinks is very competent rather than to a competent doctor who the patient thinks is ignorant. He reason is that our imagination works for our good health, and as long as it is supplemented by remedies, it is capable of healing us. But the most powerful remedies are too weak when the imagination does not apply them.

This has been reprinted many times with slight variations on the wording; it is part of a much larger quote directly from Edison published in 1903:
:Nineteen hundred and three will bring great advances in surgery, in the study of bacteria, in the knowledge of the cause and prevention of disease. Medicine is played out. Every new discovery of bacteria shows us all the more convincingly that we have been wrong and that the million tons of stuff we have taken was all useless.
The doctor of the future will give no medicine, but will instruct his patient in the care of the human frame, in diet and in the cause and prevention of disease.
They may even discover the germ of old age. I don't predict it, but it might be by the sacrifice of animal life human life could be prolonged.
Surgery, diet, antiseptics — these three are the vital things of the future in preserving the health of humanity. There were never so many able, active minds at work on the problems of diseases as now, and all their discoveries are tending to the simple truth — that you can't improve on nature.
:* As quoted in "Wizard Edison" in The Newark Advocate (2 January 1903), p. 1 according to research by Barbara and David P. Mikkelson at snopes.com http://www.snopes.com/quotes/edison.asp.
1900s

Larry King Live interview (2010)
Context: The country can't get well if the people are sick. And the people are sick. Now, I know Obama's not been the best president and the Democrats are not the best politicians, but you know what? We elected him just two years ago to fix this massive bunch of problems we have. And because he didn't do it by football season, we are ready to throw him out on the street and bring back the guys who messed it up just two years ago. That's a little too impatient. Yes, when he got the patient, the patient was bleeding to death — he got the patient to stop bleeding. But, OK, the patient is not up and back at the office quite yet. It's no reason to throw the doctor out and get back the doctor who was using leaches.

Source: Nineteen Minutes

On doctors who ask patients to avoid Ayurveda, as quoted in " Doctors prescribing non-ayurvedic medicines are anti-national http://m.timesofindia.com/city/kolhapur/Doctors-prescribing-non-ayurvedic-medicines-are-anti-national/articleshow/52058067.cms", The Times of India (30 April 2016)