Doctors use information as part of the therapeutic regimen; it is given out in amounts, in admixtures, and according to timing believed best for patients. Accuracy, by comparison, matters far less. The patient may be told nothing at all or only part of the story, or relevant information may be couched in technical or euphemistic language, calculated to deceive. There are instances where medical researchers have withheld information about the possible effects of an experimental drug or procedure, and at least one in the USA where researchers undertaking a drug testing programme, owned shares in the biotechnology company manufacturing the drug.
In Japan, doctors are often so revered and secretive that they do not tell a patient that he has terminal cancer. Most doctors in a number of 1970s surveys in the USA said that they would not, as a rule, inform patients that they have cancer. However, 80% of patients with potentially serious illnesses said they would want to be told of such a diagnosis. Growing numbers are now signing statement know as "living wills", in which they can specify whether or not they would want to be informed about a serious condition; also to specify conditions under which they do not want to have their lives prolonged.
Patients are generally in favour of being told the truth about their condition. Uncertainty and confusion can often be more unsettling than the truth, which is crucial to the restoration of some control over one's affairs. There also is evidence that people recover faster from surgery and tolerate pain with less medication if they understand what ails them and what can be done for them.
It is meaningless to speak of telling the truth, the whole truth, and nothing but the truth to a patient. It is meaningless because it is impossible. Physicians know only too well how uncertain a diagnosis or prognosis can be. They know how hard it is to give meaningful and correct answers regarding health and illness. Medicine is a profession which traditionally has been guided by a precept that transcend the virtue of uttering truth for truth's sake: so far as possible, do no harm. You can do harm by the process that is quaintly called telling the truth. You can do harm by lying. But try to do as little harm as possible.