I've never read up on other countries dealing with it.
I think our problem is largely with the CAFs risk aversion. That's combined with medicals policy to essentially just believe whatever they're told by someone coming in.
("Even if someone is obviously lying there must be a reason they're lying so it's still an issue").
Add Calian doctors into the mix who may not get the bigger picture of giving out of shape soldiers consecutive 30 day no PT chits.
I'm sure everyone deals with it, we just have a very low bar for MELs and TCats.