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My #thread summary of this new paper: ‘Face Masks Against COVID-19: An Evidence Review’ @Ldnontmayor @st3v3turn3r @ElizabethPeloza @MohamedMOSalih @shawnwlewis @jesse_helmer @MaureenPCassidy @JoshMorganLDN @AnnaHopkins11 @ArielkeK @Healthmac link: https://bit.ly/30iZCSh #LdnOnt
1. I hope this provides politicians and others with scientific data to inform their decisions. I’ll try to minimize scientific jargon & provide the info in a manner that’s minimally affected by this twitter format smiley. References are shown as: (refXX) … Here goes! #LdnOnt
2. Goal of the review is to ‘present an interdisciplinary narrative review of the literature on the role of face masks in reducing COVID-19 transmission in the community’, since ‘policymakers need urgent guidance on the use of masks by the general population’
3. Paper has 18 expert authors led by @jeremyphoward; 155 references cited; Bottom line: ‘We recommend that public officials and governments strongly encourage the use of widespread face masks in public, including the use of appropriate regulation.’
4. Multiple studies: show masks were effective (ref10) and ‘could result in a large reduction in risk of infection’ (ref11) and are ‘strongly protective’ (ref13) … but there are caveats as some studies didn’t look at all types of masks.
5. Other studies: ‘Community mask use by well people could be beneficial, particularly for COVID-19, where transmission may be pre-symptomatic.’ (ref 17) … So, you may have virus but can reduce its spread by using a mask.
6. International Population studies: transmission was 7.5 times higher in countries that did not have a mask mandate or universal mask use (ref 31), a result similar to that found in another study of fewer countries (ref 32).
7. In US states: masking mandates have prevented 230,000 to 450,000 COVID-19 cases by May 22, 2020 (ref 33). Clearly some US states are now paying a price for not doing so.
8. Models show a significant impact when at least 80% of population is wearing masks, versus minimal impact when only 50% or less is wearing masks (ref39). Given the apparent low compliance for masks in many #LdnOnt retail stores, this supports #MandatoryMasks.
9. Potential positive economic impact: masks would lessen impact of economic shutdowns in US by 1 $Trillion … Goldman Sachs analysis: https://cbsn.ws/3eAbyV3
10. Next: Cloth masks relative to surgical masks. Generally available household materials had between 58 - 94% filtration for bacteria particles vs surgical masks filtering 96% of particles (ref80); Cloth masks filtered 60% of particles vs surgical masks (75%; ref81).
11. So ‘Overall, it appears that cloth face covers can provide good fit & filtration for PPE in some community contexts, but results will vary depending on material and design, the way they are used, & the setting in which they are used.’
12. Risky behaviour: Physical distancing may be improved by mask usage (ref 113) … ‘Accompanying masks with accurate messaging + other preventative measures would display trust in the general public’s ability to act responsibly and empower citizens’ (ref 112)
13. Universal mask wearing could serve as a positive, visible signal and reminder of the pandemic (ref 126) and ‘can provide feelings of empowerment and self-efficacy’ (ref 129). Hence, it becomes standard practice. #VisualCues
14. Challenges do exist, specifically in the context of children in classroom settings and that effectiveness is dependent on compliance (ref 149). But that’s a whole other discussion at the Ministry / School Board levels #ClockIsTicking #Yikes
15. Take Home Message (THM) #1: Paper offers ‘evidence in favor of widespread mask use as source control to reduce community transmission’ … ‘non-medical masks use materials that obstruct droplets of the necessary size’
16. THM #2: ‘non-medical masks have been effective in reducing transmission’; and ‘places and time periods where mask usage is required or widespread have shown substantially lower community transmission.’
17. THM #3: Economic analysis suggests that the impact of mask wearing could be thousands of dollars saved per person per mask, coinciding with shortened economic shutdowns.
18. THM #4: Although researchers may reasonably disagree on the magnitude of the effects of masking, even modest benefits can add up. ‘Therefore, widespread use of masks in the community should be utilized’. #WashHands #SocialDistancing
19. THM #5: ‘When used in conjunction with widespread testing, contact tracing, quarantining of anyone that may be infected, hand washing, and physical distancing, face masks are a valuable tool to reduce community transmission.’
20. THM #6: Keeping transmissions low enough to preserve health care capacity will be critical until a vaccine can be developed. Mask wearing may be instrumental in preventing a second wave of infections from overwhelming the health care system.
21. THM #7: ‘Models suggest that public mask wearing is most effective at reducing spread of the virus when compliance is high’ … ‘recommendations need to be strengthened to ensure high compliance’. Hint: #MandateMasks #LdnOnt
22. and finally … THM #8: ‘We recommend the adoption of public cloth mask wearing, as an effective form of source control, in conjunction with existing hygiene, distancing, and contact tracing strategies.’ To me, #MandatoryMasks is a no-brainer.
23. Thanks for reading! Clearly, this is an active fast-moving field requiring a preventative approach, with Phase 3 upon us. I hope this thread provides insight into supporting mandatory masking in #LdnOnt … The original paper can be accessed here: https://bit.ly/30iZCSh /end
