4 ms·

First, let's (not be tedious and) agree that the reason healthcare workers wear masks is to prevent airborne infections, especially of SARS-Cov-2. Now clearly

by jdc 6y ago

First, let's (not be tedious and) agree that the reason healthcare workers wear masks is to prevent airborne infections, especially of SARS-Cov-2. Now clearly your first and second points contradict each other. Furthermore the absence of evidence is not the evidence of absence. Cf. Peer reviewed studies, or lack thereof, supporting the 6 ft "social" distancing protocol and, up until recently, the use of parachutes while jumping out of a plane.

DanBC 6y ago
> agree that the reason healthcare workers wear masks is to prevent airborne infections, especially of SARS-Cov-2. There's a big difference between a healthcare professional spending time in close contact with symptomatic people and a member of the public spending time walking round a supermarket. And healthcare professionals do not "wear masks", they wear a full set of PPE including gloves, gown, mask, eye protection. They also have access to running water and soap, and alcohol hand gels. > Peer reviewed studies, or lack thereof, supporting the 6 ft "social" distancing protocol No, we have studies supporting 1 metre distancing and recommending 2 meter distancing. The evidence for this distancing is much stronger than the evidence for mask wearing.
- jdc 6y ago
  Healthcare professionals absolutely do wear masks. Words have meanings. Let's make our minds up about whether the lack of papers supporting mask-wearing against the virus is reason not to wear their them. Also I'm earnestly interested in your source on the distancing evidence.
  - DanBC 6y ago
    But the mask is part of a set of PPE. By ignoring the eyes you're ignoring an important route. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30313-5/fulltext https://www.thelancet.com/journals/lancet/article/PIIS0140-6... > 2019-nCoV transmission through the ocular surface must not be ignored Source for distancing: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)31142-9/fulltext https://www.thelancet.com/journals/lancet/article/PIIS0140-6... Findings Our search identified 172 observational studies across 16 countries and six continents, with no randomised controlled trials and 44 relevant comparative studies in health-care and non-health-care settings (n=25 697 patients). Transmission of viruses was lower with physical distancing of 1 m or more, compared with a distance of less than 1 m (n=10 736, pooled adjusted odds ratio [aOR] 0·18, 95% CI 0·09 to 0·38; risk difference [RD] −10·2%, 95% CI −11·5 to −7·5; moderate certainty); protection was increased as distance was lengthened (change in relative risk [RR] 2·02 per m; pinteraction=0·041; moderate certainty). Face mask use could result in a large reduction in risk of infection (n=2647; aOR 0·15, 95% CI 0·07 to 0·34, RD −14·3%, −15·9 to −10·7; low certainty), with stronger associations with N95 or similar respirators compared with disposable surgical masks or similar (eg, reusable 12–16-layer cotton masks; pinteraction=0·090; posterior probability >95%, low certainty). Eye protection also was associated with less infection (n=3713; aOR 0·22, 95% CI 0·12 to 0·39, RD −10·6%, 95% CI −12·5 to −7·7; low certainty). Unadjusted studies and subgroup and sensitivity analyses showed similar findings. Interpretation The findings of this systematic review and meta-analysis support physical distancing of 1 m or more and provide quantitative estimates for models and contact tracing to inform policy. Optimum use of face masks, respirators, and eye protection in public and health-care settings should be informed by these findings and contextual factors. Robust randomised trials are needed to better inform the evidence for these interventions, but this systematic appraisal of currently best available evidence might inform interim guidance.

by jdc 6y ago

DanBC 6y ago

> agree that the reason healthcare workers wear masks is to prevent airborne infections, especially of SARS-Cov-2. There's a big difference between a healthcare professional spending time in close contact with symptomatic people and a member of the public spending time walking round a supermarket. And healthcare professionals do not "wear masks", they wear a full set of PPE including gloves, gown, mask, eye protection. They also have access to running water and soap, and alcohol hand gels. > Peer reviewed studies, or lack thereof, supporting the 6 ft "social" distancing protocol No, we have studies supporting 1 metre distancing and recommending 2 meter distancing. The evidence for this distancing is much stronger than the evidence for mask wearing.

jdc 6y ago
Healthcare professionals absolutely do wear masks. Words have meanings. Let's make our minds up about whether the lack of papers supporting mask-wearing against the virus is reason not to wear their them. Also I'm earnestly interested in your source on the distancing evidence.
- DanBC 6y ago
  But the mask is part of a set of PPE. By ignoring the eyes you're ignoring an important route. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30313-5/fulltext https://www.thelancet.com/journals/lancet/article/PIIS0140-6... > 2019-nCoV transmission through the ocular surface must not be ignored Source for distancing: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)31142-9/fulltext https://www.thelancet.com/journals/lancet/article/PIIS0140-6... Findings Our search identified 172 observational studies across 16 countries and six continents, with no randomised controlled trials and 44 relevant comparative studies in health-care and non-health-care settings (n=25 697 patients). Transmission of viruses was lower with physical distancing of 1 m or more, compared with a distance of less than 1 m (n=10 736, pooled adjusted odds ratio [aOR] 0·18, 95% CI 0·09 to 0·38; risk difference [RD] −10·2%, 95% CI −11·5 to −7·5; moderate certainty); protection was increased as distance was lengthened (change in relative risk [RR] 2·02 per m; pinteraction=0·041; moderate certainty). Face mask use could result in a large reduction in risk of infection (n=2647; aOR 0·15, 95% CI 0·07 to 0·34, RD −14·3%, −15·9 to −10·7; low certainty), with stronger associations with N95 or similar respirators compared with disposable surgical masks or similar (eg, reusable 12–16-layer cotton masks; pinteraction=0·090; posterior probability >95%, low certainty). Eye protection also was associated with less infection (n=3713; aOR 0·22, 95% CI 0·12 to 0·39, RD −10·6%, 95% CI −12·5 to −7·7; low certainty). Unadjusted studies and subgroup and sensitivity analyses showed similar findings. Interpretation The findings of this systematic review and meta-analysis support physical distancing of 1 m or more and provide quantitative estimates for models and contact tracing to inform policy. Optimum use of face masks, respirators, and eye protection in public and health-care settings should be informed by these findings and contextual factors. Robust randomised trials are needed to better inform the evidence for these interventions, but this systematic appraisal of currently best available evidence might inform interim guidance.