If you have no idea who Cochran that already says a lot and you still have not provided link to your “gold standard mechanical study” which is utterly useless regardless for real life application.
It has become obvious you are a troll on this issue and blatantly trying to obfuscate the issue.
Now you try to stand on the term uncontrolled showing you have absolutely zero understanding that is exactly what any aggregate study of all other studies are. You show you have no clue how such studies work.
Once again explain how your vaunted, still not linked mechanical study translate to life application, hell you have not even acknowledge the study you are referring to is for N95 or better because your study is not applicable to the non sealed surgical masks everyone was using.
I am done responding to you, until you link the study AND show it applies to he paper masks in question AND how that applies to the common usage node in question anything else you trow out is a waste of everyone’s time.
I am not a troll, just not a rigid ideologue idiot. What Cochrane reviews is irrelevant if you don’t understand the problems with uncontrolled population studies they based their analysis on.
Regardless you totally missed the point of my initial response. The question was do masks offer protection against COVID. No uncontrolled population study can answer that. The only way to measure the efficiency of a mask is to actually test the mask.
Bullet proof vests offer protection but if you looked at a population of people that wore them, you would see plenty of people injured and killed while wearing them. That doesn’t mean the vests didn’t work at all, it means there was some other unknown variables in that group.