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Cochrane review is out and masks have weak evidence that they are not effective

vinayprasadmdmph.substack.com

This one is against rationalists because when Scott wrote his review that masks could be effective many of us trusted it.

I don't blame Scott for failing this one because doing review of hundreds of studies is hard and one person can hardly do it. But this clearly shows that rationalist way of thinking has no special formula, they can be easily mistaken and fall by accepting general consensus just like any other person.

I was impressed when Scott did his review about masks. I trusted it because there was no other clear evidence available. Cochrane hadn't done its review yet and NICE guidelines were silent on the issue. We vaguely knew from previous studies that masks are not effective, The WHO had said so. Suddenly everyone flipped and it was not because the evidence had changed. We simply wanted to believe that masks work and we mocked those who said “no evidence that masks help”.

Even with the belief that masks work, I never wanted mask mandates. I preferred recommendations only, so that no one was penalized or prohibited entry, travel etc if one doesn't want to wear mask. Scott unwillingly had been a catalyst for governments to introduce mask mandates and all this heavy handed approach has been for nothing.

Now we are back to square one, the evidence about masks is weak and it does not support their use even in hospital settings. We can all reflect now what happened in between during these 2 or 3 years. When I realized that Scott's review is clearly insufficient as evidence, I asked some doctors if they have any better evidence that masks work. Instead of getting answer I was told not to be silly, parachutes don't need RCTs and accused me of being covid denier for nor reason. Many so-called experts were making the same mistake as Scott by looking at the issue too emotionally. It is time to get back to reality and admit that it was a mistake and we should have judged the issue with more rational mind.

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Just before seeing this post, I saw an article on social media arguing it was misleading: The Conversation: "Yes, masks reduce the risk of spreading COVID, despite a review saying they don’t". The summary of that article is that the review finds weak effects because it mixes together too many things that you would expect to have weak/no effect:

  • "mask" includes cloth/surgical masks (as opposed to [K]N95+ or equivalent masks) that we don't expect to work except maybe as source control.

  • Related, none of the studies look at masks as source control. i.e., they only study individuals wearing masks, not groups.

  • Most of the studies only had people wear masks in "high-risk" situations (i.e. around known-infected individuals) as opposed to, say, all the time while at work. Any consideration of the claimed mechanism of airborne transmission often from asymptomatic cases would lead you to expect that to not work, especially where "work" means medical settings where you have higher expectation of infected people around.

  • Bonus: none of the studies compare mask wearing to not masking wearing, only being advised to wear masks to not being advised to wear masks.

The articles claims if you pare down to only the studies looking at "Does wearing N95s all the time reduce COVID-19 transmission?" the answer is in fact "yes", the opposite of the headline.

Isn't "properly fitted N95s work" just another way of saying "mask mandates don't work"?

Exactly this. Don't even try to think seriously about articles that claim that masks work despite evidence that says they don't. It is a big fail for rationalists to even think in this way.