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> Actual facts would be something like washing your hands or boiling water preventing diseases. Nobody questions it anymore... People are questioning exactly t

by alimw 5y ago

> Actual facts would be something like washing your hands or boiling water preventing diseases. Nobody questions it anymore... People are questioning exactly these things. Germ theory itself is under attack. Masks have been used for many years in healthcare settings to hinder the spread of airborne pathogens, yet now we hear they are useless...

charbonneau 5y ago
> We included nine trials (of which eight were cluster‐RCTs) comparing medical/surgical masks versus no masks to prevent the spread of viral respiratory illness (two trials with healthcare workers and seven in the community). There is low certainty evidence from nine trials (3507 participants) that wearing a mask may make little or no difference to the outcome of influenza‐like illness (ILI) compared to not wearing a mask (risk ratio (RR) 0.99, 95% confidence interval (CI) 0.82 to 1.18) [1] The effectiveness of masks is complicated. It is not a black or white situation. [1] https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD006207.pub5/full?contentLanguage=en https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD...
- alimw 5y ago
  "The design of most trials assessed whether masks protected the wearer."
  - charbonneau 5y ago
    The very next line: > Four trials were cluster-RCTs, with all participants in the intervention clusters required to wear masks, thus assessing both source control and personal protection > In two [of the four] trials the clusters were households with a member with new influenza; neither of these studies found any protective effect > In two [of the four] trials the clusters were college dormitories during the influenza season; neither study found any reduction I wouldn't go as far as saying that masks do not work. At the same time, I wouldn't go as far as saying that they do work. Reality is messy. If you want to wear a mask, do it. If not, don't.
    - alimw 5y ago
      Nobody wants to wear a mask! > Reality is messy. I understand that in this era of "alternative facts" the view is not universally shared, but I do believe that reality contains objective truths if only we can get at them. Either masks hinder the spread of germs (in the prior this has high probability based on logic and the experience of many years) or they don't. We are down to four trials now instead of nine, and only three that count, since one was excluded by these authors for methodological shortcomings. Don't blame it on "reality" that none of these was sufficiently large to establish the truth either way.
      - charbonneau 5y ago
        Let me rephrase: If you feel the need to wear a mask, do it. If not, don't. Edit: > in the prior this has high probability based on logic and the experience of many years Reality can be counter-intuitive if you put your logic and experience to the test. Famous example: Using diuretics for antidiuretic effects [1] Even a banal situation like wearing a face mask during surgery leads to inconclusive results [2]. Does it increase or decrease the number of cases of wound infections? There seems to be no clear evidence atm [1] https://jasn.asnjournals.org/content/15/11/2948 https://jasn.asnjournals.org/content/15/11/2948 [2] https://www.cochrane.org/CD002929/WOUNDS_disposable-surgical-face-masks-preventing-surgical-wound-infection-clean-surgery https://www.cochrane.org/CD002929/WOUNDS_disposable-surgical...

by alimw 5y ago

charbonneau 5y ago

> We included nine trials (of which eight were cluster‐RCTs) comparing medical/surgical masks versus no masks to prevent the spread of viral respiratory illness (two trials with healthcare workers and seven in the community). There is low certainty evidence from nine trials (3507 participants) that wearing a mask may make little or no difference to the outcome of influenza‐like illness (ILI) compared to not wearing a mask (risk ratio (RR) 0.99, 95% confidence interval (CI) 0.82 to 1.18) [1] The effectiveness of masks is complicated. It is not a black or white situation. [1] https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD006207.pub5/full?contentLanguage=en https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD...

alimw 5y ago
"The design of most trials assessed whether masks protected the wearer."
- charbonneau 5y ago
  The very next line: > Four trials were cluster-RCTs, with all participants in the intervention clusters required to wear masks, thus assessing both source control and personal protection > In two [of the four] trials the clusters were households with a member with new influenza; neither of these studies found any protective effect > In two [of the four] trials the clusters were college dormitories during the influenza season; neither study found any reduction I wouldn't go as far as saying that masks do not work. At the same time, I wouldn't go as far as saying that they do work. Reality is messy. If you want to wear a mask, do it. If not, don't.
  - alimw 5y ago
    Nobody wants to wear a mask! > Reality is messy. I understand that in this era of "alternative facts" the view is not universally shared, but I do believe that reality contains objective truths if only we can get at them. Either masks hinder the spread of germs (in the prior this has high probability based on logic and the experience of many years) or they don't. We are down to four trials now instead of nine, and only three that count, since one was excluded by these authors for methodological shortcomings. Don't blame it on "reality" that none of these was sufficiently large to establish the truth either way.
    - charbonneau 5y ago
      Let me rephrase: If you feel the need to wear a mask, do it. If not, don't. Edit: > in the prior this has high probability based on logic and the experience of many years Reality can be counter-intuitive if you put your logic and experience to the test. Famous example: Using diuretics for antidiuretic effects [1] Even a banal situation like wearing a face mask during surgery leads to inconclusive results [2]. Does it increase or decrease the number of cases of wound infections? There seems to be no clear evidence atm [1] https://jasn.asnjournals.org/content/15/11/2948 https://jasn.asnjournals.org/content/15/11/2948 [2] https://www.cochrane.org/CD002929/WOUNDS_disposable-surgical-face-masks-preventing-surgical-wound-infection-clean-surgery https://www.cochrane.org/CD002929/WOUNDS_disposable-surgical...