3 ms·

> The best model might be wear masks There's not much evidence that masks help, and there's lots of evidence that poorly worn masks cause harm. There's some e

by DanBC 7y ago

> The best model might be wear masks There's not much evidence that masks help, and there's lots of evidence that poorly worn masks cause harm. There's some evidence that home made cloth masks are worse than nothing. https://www.medrxiv.org/content/10.1101/2020.03.30.20047217v1.full.pdf https://www.medrxiv.org/content/10.1101/2020.03.30.20047217v... > MacIntyre 2015 25 also included a trial arm with cloth masks and found that the rate of ILI was higher in the cloth mask arm compared to medical/surgical masks (RR 13.25, 95%CI 1.74 to 100.97) and compared to no masks (RR 3.49, 95%CI 1.00 to 12.17).

nokcha 7y ago
>There's some evidence that home made cloth masks are worse than nothing. >MacIntyre 2015 That paper is studying whether wearing a mask protects the user of the mask. But the purpose of universal wearing of cloth masks is mainly to protect people from the wearer. (Many people infected with COVID-19 are contagious without showing symptoms.) And the study wasn't really "cloth mask vs no mask". It was "cloth mask" vs "sometimes wearing a medical-grade mask and sometimes wearing no mask": > (1) medical masks at all times on their work shift; (2) > cloth masks at all times on shift or (3) control arm > (standard practice, which may or may not include mask > use). Standard practice was used as control because the > IRB deemed it unethical to ask participants to not wear > a mask. ... > Cloth masks resulted in significantly higher rates of infection than > medical masks, and also performed worse than the control > arm. The controls were HCWs who observed standard practice, > which involved mask use in the majority, albeit with > lower compliance than in the intervention arms. The > control HCWs also used medical masks more often than cloth masks.
- DanBC 7y ago
  > But the purpose of universal wearing of cloth masks is mainly to protect people from the wearer. Cloth masks definitely don't protect other people from the wearer. What's the mechanism of action there? Someone coughs, but that shitty cloth mask i) catches everything and ii) the wearer doesn't fiddle with it all day and then touch everything around them?

by DanBC 7y ago

nokcha 7y ago

>There's some evidence that home made cloth masks are worse than nothing. >MacIntyre 2015 That paper is studying whether wearing a mask protects the user of the mask. But the purpose of universal wearing of cloth masks is mainly to protect people from the wearer. (Many people infected with COVID-19 are contagious without showing symptoms.) And the study wasn't really "cloth mask vs no mask". It was "cloth mask" vs "sometimes wearing a medical-grade mask and sometimes wearing no mask": > (1) medical masks at all times on their work shift; (2) > cloth masks at all times on shift or (3) control arm > (standard practice, which may or may not include mask > use). Standard practice was used as control because the > IRB deemed it unethical to ask participants to not wear > a mask. ... > Cloth masks resulted in significantly higher rates of infection than > medical masks, and also performed worse than the control > arm. The controls were HCWs who observed standard practice, > which involved mask use in the majority, albeit with > lower compliance than in the intervention arms. The > control HCWs also used medical masks more often than cloth masks.

DanBC 7y ago
> But the purpose of universal wearing of cloth masks is mainly to protect people from the wearer. Cloth masks definitely don't protect other people from the wearer. What's the mechanism of action there? Someone coughs, but that shitty cloth mask i) catches everything and ii) the wearer doesn't fiddle with it all day and then touch everything around them?