COVID-19 Evidence Alerts
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Current best evidence for clinical care (more info)

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Primary Prevention Tabatabaeizadeh SA Airborne transmission of COVID-19 and the role of face mask to prevent it: a systematic review and meta-analysis. Eur J Med Res. 2021 Jan 2;26(1):1. doi: 10.1186/s40001-020-00475-6.

BACKGROUND AND AIMS: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), belonging to the Coronaviridae family, is agent of 2019 novel coronavirus disease (COVID-19). COVID-19 emerged in Wuhan, Hubei province of China, in early December 2019 and is now considered a pandemic. This study aimed to investigate the airborne transmission of COVID-19 and the role of face mask to prevent it.

METHODS: A systematic search for English-language literature was done via PUBMED/Medline and Google Scholar up to October 2020. There was two search strategy; for airborne transmission and the role of face mask for prevention of SARS-CoV-2 infection. Based on a fixed and random effects model, the RR and 95% CI were used to evaluate the combined risk. This meta-analysis followed Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) Guidelines.

RESULTS: After eligibility assessment, four articles with a total of 7688 participants were included in this meta-analysis. The result of this meta-analysis has shown significant reduction in infection with face mask use; the pooled RR (95%CI) was 0.12 [0.06, 0.27] (P < 0.001).

CONCLUSION: In conclusion, this meta-analysis suggests that there is association between face mask use and reduction of COVID-19. However, COVID-19 spreads primarily with contact routes and respiratory droplets, but its transmissibility has many mysteries yet and there is controversy about airborne transmission of COVID-19.

Discipline / Specialty Area Score
Public Health
Family Medicine (FM)/General Practice (GP)
General Internal Medicine-Primary Care(US)
Hospital Doctor/Hospitalists
Internal Medicine
Occupational and Environmental Health
Comments from MORE raters

Family Medicine (FM)/General Practice (GP) rater

This is a helpful review and meta-analysis of mask wearing that should inform public health practice.

General Internal Medicine-Primary Care(US) rater

With only 4 studies, the authors should have described individual studies in greater detail. I am a big fan of masks and wholeheartedly believe in their effectiveness (have protected me and most of my colleagues!) but studies of this are clearly difficult - this MA does not shed much additional light (but I'm happy people will cite it as "proof" of effectiveness given the many naysayers out there in the non-clinical world).

Internal Medicine rater

This is not that useful as this information is widely known.

Occupational and Environmental Health rater

Although relevant, I think some of the background discussion of droplet vs aerosol and the utility of masks with type unspecified precludes any actionable change in practice because some mask types are effective for droplets and others aerosols. The distinction is not clear in this article, nor is it clear that the paper lumped for metanalysis were considering the same mask types. Thus, although the analysis seems well done, the data selection for the analysis and the conclusions resulting are not sufficiently expert for me to advise practice change. As well, I recommend examining the work of Dr. James Scott at the Dalla Lana School of Public health who discusses these issues in detail.

Occupational and Environmental Health rater

This kind of argument will continue.

Public Health rater

This is an important topic. However, the article is poorly written.