In medical seminars I used to get the same questions over and over again (which was my reason for writing Language in Emergency Medicine -- to get the answers to that set of constant questions stashed in one place between two covers). One of the most common questions had to do with what I call the "Aunt Grace Syndrome", and it went like this:
"What do I do about the old lady who comes to the ER with chest pain and won't answer any of my questions and just keeps saying she knows what's wrong with her because her Aunt Grace had the very same thing?"
I went to a number of ERs and watched this happening, to get it straight in my mind, and it was definitely a problem that needed solving. The medpro would try to ask the usual set of questions, the elderly woman would stick to her guns, no information except ever-increasing mutual hostilitly would be exchanged. And pretty soon the patient was saying "I may be old, young man, but I'm not senile!", the medpro was completely ballistic, and time -- horribly expensive time -- was a-wasting all the while. Dreadful.
So I suggested to the EM doctors that they apply Miller's Law. I suggested that they assume (not accept, just assume) that what the patient is saying is true, and then proceed as follows:
"When your Aunt Grace had this pain, where was it?"
"When your Aunt Grace had this pain, how long did it last?"
"When your Aunt Grace had this pain, was there anything that made it worse, or made it better?"
[And so on.]
This works like magic. Nobody gets mad. The doctor gets the necessary information quickly. The patient doesn't feel insulted. Time is not wasted, energy is not wasted, the medical language environment in the ER is not polluted with a lot of hostile language and hostile vibes. And the patient can be counted on to volunteer anything extra that's needed, such as "Well, when Grace had it it always lasted a couple of hours, but with me it's more like half an hour."
Thank goodness for George Miller....
PS: You're quite right -- it isn't always an elderly woman who does this. Sometimes it's an elderly man; sometimes it's a younger person. But very often it's an elderly woman; the medpros aren't making that up.