One of the things I must do when someone is making a really bad (meaning high-risk) decision is assess decisional capacity. Does the patient understand the reason for my recommendations? Does the patient understand my explanation of the risks of not following those recommendations? Is the patient genuinely willing to accept those risks? Can the patient explain why s/he is rejecting the advice and why s/he thinks it makes sense to accept the risks?

It should be apparent that, at the same time this process enables me to assess decisional capacity, it also allows me to make sure there have been no misunderstandings of the information I’ve conveyed and to correct any there may be.

All of this requires significantly time-consuming verbal communication. I must be satisfied that the patient really understands my advice, and the risks, and that requires that the patient explain them back to me in his own words. I also need him to explain his reasons for rejecting the advice. His reasons for rejecting the advice don’t have to satisfy my sense of what is logical or rational or makes sense. So, for example, if he gives me a list of recently deceased friends and relatives and tells me they all died in hospitals, and so there is no way he is going to stay in a hospital, and he rejects all my attempts to demonstrate the logical fallacies in his reasoning, that doesn’t mean he lacks decisional capacity.

If, on the other hand, he tells me if he stays in the hospital, as soon as he falls asleep tonight, space aliens or demons from Hell will appear in his room and abduct or incinerate him, I will be inclined to think he is delusional and mentally ill and does not have decisional capacity. (For the sake of clarity, I should note that a delusion is not a belief that is merely false. Rather, it is a belief that could not possibly be true.)

If his decision is based on values that are different from mine, I must respect that. For example, he may be perfectly comfortable with the risk of death and prefer to take his chances and die at home rather than be hospitalized and subjected to modern medical technology. I may then wonder (and even ask) why he came to the hospital in the first place, and my values may be completely different, because if I were similarly situated, I would want to live to see my grandchildren graduate from college and get married.