Afaik, this is an apples-to-oranges type thing. Cochrane's analysis is that they can't say if masks are effective or not. It's not evidence of harm or helpfuln

Afaik, this is an apples-to-oranges type thing. Cochrane's analysis is that they can't say if masks are effective or not. It's not evidence of harm or helpfulness. A similar way to think about this is if I show you a coin and ask you if it's weighted? You don't have enough information to make a determination (perhaps if I flip it a bunch of times you can claim one way but that's not part of the question/data). I didn't run any statistical analysis on their tables but given that their "Viral respiratory illness ‐ influenza/COVID‐like illness" for No Masks is 160/1000 while "Viral respiratory illness ‐ influenza‐like illness" for Masks is 50/1000 I'm guessing masks do have an effect but the amount of samples in their data is not enough to demonstrate it. Where the oranges come from is the UMD paper is studying how many viruses appear in a plague doctor's mask [1] which is obviously different than how many individuals get sick (apples). [1]: https://sph.umd.edu/sites/default/files/styles/optimized/public/2020-12/PHAB-Lab.jpg?itok=flPZtUjK https://sph.umd.edu/sites/default/files/styles/optimized/pub...