I think the point you might be missing here is that prayer didn’t make things better.
Also citing a study without noting the specifics of that study (population size, quantifying and equating the ailments, time frame of the study, what prayers were being said and to whom) dramatically limits the usefulness of that study.
Behold, the bird the pelican…. He holds more in his beak than his belly can…. He holds enough in his beak…. To last him a week…. But I don’t know how the helican.
Cue “Smooth Criminal” by Michael Jackson