https://www.acpjournals.org/doi/10.7326/M20-6817 Results: A total of 3030 participants were randomly assigned to the recommendation to wear masks, and 2994 were assigned to control; 4862 completed the study. Infection with SARS-CoV-2 occurred in 42 participants recommended masks (1.8%) and 53 control participants (2.1%). The between-group difference was −0.3 percentage point (95% CI, −1.2 to 0.4 percentage point; P = 0.38) (odds ratio, 0.82 [CI, 0.54 to 1.23]; P = 0.33). Multiple imputation accounting for loss to follow-up yielded similar results. Although the difference observed was not statistically significant, the 95% CIs are compatible with a 46% reduction to a 23% increase in infection. Limitation: 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. Conclusion: The recommendation to wear surgical masks to supplement other public health measures did not reduce the SARS-CoV-2 infection rate among wearers by more than 50% in a community with modest infection rates, some degree of social distancing, and uncommon general mask use. The data were compatible with lesser degrees of self-protection.
So why do surgeons wear masks? Oh yeah, to protect the other guy. We're going to have to raise taxes to fix this. Sorry.
That's all you need to know about this "study" Don't you find it ironic that your Thread Title is far more conclusive than the study?
"no assessment of whether masks could decrease disease transmission from mask wearers to others." The primary reason to wear non-N95 masks is because they are 70% or more effective in preventing the transmission of COVID to others. Masks are only marginally effective (under 15%) to stopping the user from catching COVID from others.
Because of the acknowledged problems associated with the study jem quoted, the most reliable measurements of mask effectiveness are done in the laboratory with the deletion of the human variable. In the lab, there is no problem of the mask being worn below the nose, or going to play bingo at the church and forgetting to take your mask. Not surprisingly masks are less effective in a drawer at home or dangling from your neck then when worn properly on your face.
And the laboratory tests acknowledge that air flows in and out the sides of surgical masks in real life. This was not the first study to show that masks are ineffective. There are studies with medical pros which show that cloth masks don't work and dirty masks are dangerous. Which is why many hospitals make their people wear custom fit N95s and shields while treating symptomatic covid patients.
Common sense begs the question "If 85 percent of the populace have adopted mask wearing, then why is there a Kung Flu spike going on?"
Distancing works....dirty masks are dangerous...why is so hard for leftists to understand? They just want to pretend infectious people's masks never get dirty.
You and your family should wash/replace/disinfect your masks. You're the only one I know that wears a dirty mask.