Hmmm...and there are probably more people who, like you, don't understand, than that do. But that's not the point.
The reason why these numbers matter to me is because I think there is a fine line that is really hard to see - and that line is when does it become more than just your choice of treatment and turn into a choice of life or death? What chance of survival do you need to be given that makes it not even a question of whether you want the treatment or not. I think 85% is pretty high. But what if it was 100%?? Would everyone who said that the parents need to be able to choose what drugs their son gets agree that they should deny treatment that guarantees 100% that he will survive?? To me that would make a difference and the fact that he only has 5% chance of survival without it also makes a huge difference. I fail to see why people are so heated up about this when the government does make choices for people's treatments all the time, like when we call 911 because a kid is unconscious we don't ask the parents "should we let him heal naturally instead of calling 911"...How come there is not a huge debate about why we do that?