Are doctors usually right about poor prognosis?

I think it's fair: to say most doctors who went into a medicine career did so to try to save lives, or at least to improve quality of life. For a doctor to say that a patient has a poor prognosis is an admission to himself/herself that there is not much more doable to save the person from the inevitable jaws of death. However, having a poor prognosis does not necessarily mean poor quality of life. So ask about