Originally Posted by
Bio
I'm pretty sure you're right about that. Basically, N95 is the best of the non-industrial masks, then surgical, then cloth. Cloth is still better than nothing.
Edit, got the original cited article on work computer:
MacIntyre, CR etc al 2015, BMJ Open
The main, non-obvious issue from the short summary linked earlier in this article was that the control group wasn't "no masks" it was "do what you would do normally". That means the participants did what they wanted. Of 458 members of the control group, 245 used both types of masks, probably depending on local availability (my own guess), 3 used n95s, 2 used no masks at all. The remainder of the control group used some kind of mask, but I couldn't find what type. The test groups (cloth or surgical, about 500 each) were given masks to use for the time of study.
What this means isn't that cloth masks were compared to a control of non-masked users, it's that cloth masks were compare to a control of a mix of cloth and surgical, with <1% N95 or maskless. So its obvious from more study that surgical was notably better than cloth, but its not obvious how cloth compares to maksless. Probably because you can't ask healthcare workers to stop making up because you want to know what will happen.