I think the other response was flagged for language, but the included link was really interesting. I'd never even heard of medical "lodge practice" before seeing this video and reading through some of the references.

They're basically voluntary, mutual aid societies – many of them were basically small unions. The were strangled by the bigger, consolidated organizations:

https://m.youtube.com/watch?v=fFoXyFmmGBQ

The video is probably good for most audiences, but if (like me) you prefer to read, it looks like this is the short essay it's based on: http://www.freenation.org/a/f12l3.html

The references at the end of the essay include some really interesting historical accounts which I've enjoyed reading over the past few hours.