Evidence map›Paper›PMID 33431650›Full record

ReviewProceedings of the National Academy of Sciences of the United States of America2021

An evidence review of face masks against COVID-19.

Jeremy Howard, Austin Huang, Zhiyuan Li, Zeynep Tufekci, Vladimir Zdimal, Helene-Mari van der Westhuizen, Arne von Delft, Amy Price, Lex Fridman, Lei-Han Tang and 9 more

Erratum issuedOpen access · bronzeAbstract readReview
PubMed Full text at PMC Publisher
In one paragraph

Review in Proceedings of the National Academy of Sciences of the United States of America, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 580 papers, 5 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
580citing papers in PubMed, 5 pooled it
170.5field-weighted citation impact, top 1% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

580 citing papers in PubMed, 5 syntheses or guidelines pooled it, 1,290 citations in OpenAlex.

  1. Pooled it
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  4. Pooled it
  5. Pooled it
  6. Trial
  7. Theory-based Trial to Promote Uptake and Sustained Use of Face Coverings During the COVID-19 Pandemic.Annals of behavioral medicine : a publication of the Society of Behavioral Medicine · 2023
    Trial
  8. Trial
  9. Influence of short-term face mask wear on semiautomatically measured tear film parameters in dry eye patients and healthy volunteers.Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie · 2023
    Trial
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  12. Article
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520 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

19 authors at 15 institutions in 7 countries.

Jeremy Howardfast.ai, San Francisco, CA 94105; jphoward@usfca.edu.ORCID http://orcid.org/0000-0002-3102-9282
Austin HuangWarren Alpert School of Medicine, Brown University, Providence, RI 02903.
Zhiyuan LiCenter for Quantitative Biology, Peking University, Beijing 100871, China.ORCID http://orcid.org/0000-0001-6662-2636
Zeynep TufekciSchool of Information, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599.ORCID http://orcid.org/0000-0002-7806-0025
Vladimir ZdimalInstitute of Chemical Process Fundamentals, Czech Academy of Sciences, CZ-165 02 Praha 6, Czech Republic.
Helene-Mari van der WesthuizenDepartment of Primary Health Care Sciences, University of Oxford, Oxford OX2 6GG, United Kingdom.ORCID http://orcid.org/0000-0002-9233-2349
Arne von DelftTB Proof, Cape Town 7130, South Africa.ORCID http://orcid.org/0000-0002-8785-9672
Amy PriceAnesthesia Informatics and Media Lab, School of Medicine, Stanford University, Stanford, CA 94305.ORCID http://orcid.org/0000-0002-5200-7322
Lex FridmanDepartment of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, MA 02139.
Lei-Han TangDepartment of Physics, Hong Kong Baptist University, Hong Kong SAR, China.ORCID http://orcid.org/0000-0002-2925-4691
Viola TangDepartment of Information Systems, Business Statistics and Operations Management, Hong Kong University of Science and Technology, Hong Kong SAR, China.ORCID http://orcid.org/0000-0002-8942-0348
Gregory L WatsonDepartment of Biostatistics, Jonathan and Karin Fielding School of Public Health, University of California, Los Angeles, CA 90095.ORCID http://orcid.org/0000-0001-7597-7359
Christina E BaxPerelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104.ORCID http://orcid.org/0000-0003-1319-3318
Reshama ShaikhData Umbrella, New York, NY 10031.ORCID http://orcid.org/0000-0003-4162-4453
Frederik QuestierTeacher Education Department, Vrije Universiteit Brussel, 1050 Brussels, Belgium.ORCID http://orcid.org/0000-0002-5596-3635
Danny HernandezOpenAI, San Francisco, CA 94110.
Larry F ChuAnesthesia Informatics and Media Lab, School of Medicine, Stanford University, Stanford, CA 94305.ORCID http://orcid.org/0000-0003-0814-6402
Christina M RamirezDepartment of Biostatistics, Jonathan and Karin Fielding School of Public Health, University of California, Los Angeles, CA 90095.ORCID http://orcid.org/0000-0002-8435-0416
Anne W RimoinDepartment of Epidemiology, Jonathan and Karin Fielding School of Public Health, University of California, Los Angeles, CA 90095.ORCID http://orcid.org/0000-0002-0662-9067
University of California, Los Angeles · USStanford University · USAmerican Institute of Aeronautics and Astronautics · USBrown University · USCzech Academy of Sciences, Institute of Chemical Process Fundamentals · CZFoundation for the Advancement of Social Theory · USHong Kong Baptist University · HKHong Kong University of Science and Technology · HKOpenAI (United States) · USPeking University · CNUniversity of Cape Town · ZAUniversity of North Carolina at Chapel Hill · USUniversity of Oxford · GBUniversity of Pennsylvania · USVrije Universiteit Brussel · BE

Funding

NRSA Training CoreTL1TR001880 · NCATS · UNIVERSITY OF PENNSYLVANIA · PI MEAGHER, EMMA ANNE · 2016 to 2025
$10.0M
NCATS NIH HHS TL1 TR001880
6 · The paper itself

Abstract

The science around the use of masks by the public to impede COVID-19 transmission is advancing rapidly. In this narrative review, we develop an analytical framework to examine mask usage, synthesizing the relevant literature to inform multiple areas: population impact, transmission characteristics, source control, wearer protection, sociological considerations, and implementation considerations. A primary route of transmission of COVID-19 is via respiratory particles, and it is known to be transmissible from presymptomatic, paucisymptomatic, and asymptomatic individuals. Reducing disease spread requires two things: limiting contacts of infected individuals via physical distancing and other measures and reducing the transmission probability per contact. The preponderance of evidence indicates that mask wearing reduces transmissibility per contact by reducing transmission of infected respiratory particles in both laboratory and clinical contexts. Public mask wearing is most effective at reducing spread of the virus when compliance is high. Given the current shortages of medical masks, 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. Because many respiratory particles become smaller due to evaporation, we recommend increasing focus on a previously overlooked aspect of mask usage: mask wearing by infectious people ("source control") with benefits at the population level, rather than only mask wearing by susceptible people, such as health care workers, with focus on individual outcomes. We recommend that public officials and governments strongly encourage the use of widespread face masks in public, including the use of appropriate regulation.

Indexed as

Contact TracingCOVID-19MasksSARS-CoV-2HumansCOVID-19maskspandemicSARS-CoV-2

Identifiers

PMID33431650
PMCPMC7848583
OpenAlexW3118643387

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.