I would go further. Declining a medical intervention usually has nothing to do with “deciding to die.” When patients decide to forgo a particular treatment, it’s rarely because they are in a “state worse than death.” The vast majority of people facing choices about medical care want to live—but that doesn’t mean they would undergo any and all possible medical treatments. Rather, and this is all too seldom discussed, we need to ask 3 questions when we make decisions about medical care. How much pain and suffering will I have with the proposed treatment? How likely is it to succeed? And in the best case, where it succeeds, how much longer can I expect to live?
The extremes are pretty easy. If the treatment is totally innocuous, most people would want it, even if it isn't very likely to work and even if the patient is very elderly. If it's painful (and by painful I also mean that it induces confusion or requires a long period of rehabilitation or results in dependency) and probably won't work anyway and the patient is at the very end of life, most people wouldn't want it. The more difficult situations are in between. Suppose it's painful but has a good chance of success, many though not all people would want it. Suppose it’s painful and the odds of success are small but the patient is 25 years old, many people would opt for the treatment. Not everyone will make the same choice: some people are more risk averse than others; people do not share the same values. But we need to start by asking the same basic questions.