As has already been mentioned, the algorithm would only be useful for selecting patients for studies so that they don't spend lots of time and resources on patients who then can't complete the study. I can only imagine that the "scientists" spending time on this are the same ones that prefer reading actuarial tables to talking to real people.
Our ALS specialist is a gem, and when we asked for a prognosis, he refused to speculate. He said that it would be nothing but a guess. He did say that when the breathing gets below a certain level, body mass has reached a certain level, and with a few other indicators, that this usually indicates that the person is within 6 months or so of passing. If we want to know then so we can plan for the end, he'll tell us what he sees, but other than that, he said he'd be guessing.
I told him that one neurologist had said in January of 2014 that my husband had only months to live, and our specialist replied that he hated hearing that doctors said such things. He told us about one patient who had been told by his community physician that he wouldn't make it to Christmas, but he's still alive 6 years later. The patient sends this doctor a card every Christmas that reads, "I'm still here, A*****E."
My husband has had FTD since 2001, and his respiratory-onset ALS began in early 2011. By any estimate, the FTD/ALS combination is supposed to produce a fast exit, and lung-onset is the very worst, so he got a double-whammy. Every single guesstimate would have put him in the past tense by now, but he walked up the stairs to bed just a while ago. So, these scientists will be wrong, because they may think they are, but they're NOT God, and only He decides when it's time. Scientists tend to underestimate the human will to live.