| I don't think you're operating in good faith, but since you asked, other people might find this useful. You'll also note that none of the links I am providing here are from Vinay Prasad, since you are convinced he is some kind of astroturfing organization... There have been exactly two RCTs for masks and Covid during the pandemic, neither of which has shown a large effect [1][2]. The DANMASK study showed no significant PPE effect, and the Bangladesh RCT showed a total effect size of around 0.09% (or a difference of 20 infections on base of thousands). Prior to the pandemic, RCTs for masks and respiratory disease showed weak effects, at best. Cochrane did a review of the literature [3], and found: > Seven studies took place in the community, and two studies in healthcare workers. Compared with wearing no [surgical] mask, wearing a [surgical] mask may make little to no difference in how many people caught a flu-like illness (9 studies; 3507 people); and probably makes no difference in how many people have flu confirmed by a laboratory test (6 studies; 3005 people). > We are uncertain whether wearing masks or N95/P2 respirators helps to slow the spread of respiratory viruses. There have been many uncontrolled studies published. These are useless. Uncontrolled studies are not science (the Missouri study discussed in the OP is not a controlled study, btw). There have been many laboratory studies published. These are suggestive, but just like a lab study for a drug, not meaningful in the real world without real-world evidence. [1] https://www.acpjournals.org/doi/10.7326/m20-6817 [2] https://www.poverty-action.org/sites/default/files/publicati... [3] https://www.cochrane.org/CD006207/ARI_do-physical-measures-s... |
> Inconclusive results, missing data, variable adherence, patient-reported findings on home tests, no blinding, and no assessment of whether masks could decrease disease transmission from mask wearers to others.
The Bangladesh study found masks were effective.
The third is a literature review with no indication of quality control, so basically as reliable as the Danish study (no policing of actual mask wearing, no policing of proper mask wearing, no policing of mask hygiene).