no-op000
The flaw in my thinking was the word "patients" - what I've found is that those in the grip of a bad condition rarely have the ability to altruistically contribute data, and by definition have not yet found a treatment that works. For those lucky enough to find a cure, they are not in patient communities any more, nor are they reachable via keyword advertising and the like.
Gathering data to find out which protocols work for what requires the medical community to share medical histories and treatment outcomes like software developers share code. Alas, they lack the culture and data collection discipline to do it - I've tried. Even large entities that pay hospital groups for anonymized data have trouble getting good outcome data due to poor data collection practices and the tendency for patients whose treatments failed to just leave for another doctor.