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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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Rationality is actually about understanding the hierarchy of evidence strength. Yes, meta-analyses can be wrong too, but in this case Cochrane report is pretty solid. Even though it is not definitive, it makes no sense to reject it and value some anecdotal cases or even lab based evidence as higher evidence.

Using that logic, do you think handwashing prevents covid? From the review:

SARS‐CoV‐2 [is] considered to be predominantly spread via respiratory particles of varying size or contact routes, or both (WHO 2020c). Data from studies of SARS‐CoV‐2 contamination of the environment based on the presence of viral ribonucleic acid and infectious virus suggest significant fomite contamination (Lin 2022; Onakpoya 2022b; Ong 2020; Wu 2020). Hand hygiene would be expected to be beneficial in reducing the spread of SARS‐CoV‐2 similar to other beta coronaviruses (SARS‐CoV‐1, Middle East respiratory syndrome (MERS), and human coronaviruses), which are very susceptible to the concentrations of alcohol commonly found in most hand‐sanitiser preparations (Rabenau 2005; WHO 2020c). Support for this effect is the finding that poor hand hygiene, despite the use of full personal protective equipment (PPE), was independently associated with an increased risk of SARS‐CoV‐2 transmission to healthcare workers in a retrospective cohort study in Wuhan, China in both a high‐risk and low‐risk clinical unit for patients infected with COVID‐19 (Ran 2020). The practice of hand hygiene appears to have a consistent effect in all settings, and should be an essential component of other interventions.

The general overview states: Pooled data showed that hand hygiene may be beneficial with an 11% relative reduction of respiratory illness (RR 0.89, 95% CI 0.83 to 0.94; low‐certainty evidence), but with high heterogeneity.

Covid as such is basically over now but respiratory illnesses remain. 11% is not much but it is at least something.