things...in this particular instance, the link from WestCoast had this caveat...
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However, Dr. Marc Siegel, professor of medicine at NYU Langone Medical Center and a Fox News medical contributor, pointed out a key limitation: "The researchers focus primarily on randomized trials, but most of the studies that have been done on masks are population studies," he said.
"There are very few randomized trials on masks."
In a randomized trial, researchers place participants in different groups and observe the results in a controlled environment.
By contrast, population-based studies measure outcomes in a "real-world" setting.
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On a less rigorous level, it's annoying to me to see so many "Probably's"..."Little's", etc. in the review...as opposed to the NEJM study that specifically showed the data...using the very rigorous "Difference-in-Difference" method to make their unambiguous conclusion that MASKS WORK....btw, if you'd like more on the rationale and workings of "Difference-in-Difference", I'll be glad to provide a link for you.
Link: https://www.mdlinx.com/article/cochrane-reviews-controversy-are-the-concerns-valid/7tjNVFB6sLR2l9VoaXqQDc