lancet-header

Preprints with The Lancet is part of SSRN´s First Look, a place where journals identify content of interest prior to publication. Authors have opted in at submission to The Lancet family of journals to post their preprints on Preprints with The Lancet. The usual SSRN checks and a Lancet-specific check for appropriateness and transparency have been applied. Preprints available here are not Lancet publications or necessarily under review with a Lancet journal. These preprints are early stage research papers that have not been peer-reviewed. The findings should not be used for clinical or public health decision making and should not be presented to a lay audience without highlighting that they are preliminary and have not been peer-reviewed. For more information on this collaboration, see the comments published in The Lancet about the trial period, and our decision to make this a permanent offering, or visit The Lancet´s FAQ page, and for any feedback please contact preprints@lancet.com.

Mask Use in Community Settings in the Context of COVID-19: A Systematic Review of Ecological Data

74 Pages Posted: 26 May 2021

See all articles by Nathan Ford

Nathan Ford

World Health Organization - Guidelines Review Committee

Haley K. Holmer

VA Portland Health Care System - Center to Improve Veteran Involvement in Care (CIVIC)

Roger Chou

Oregon Health and Science University

Paul Villeneuve

Carleton University - School of Mathematics and Statistics and Department of Neurosciences

April Baller

World Health Organization - Health Emergency Programme

Maria Van Kerkhove

World Health Organization - Health Emergency Programme

Benedetta Allegranzi

World Health Organization - Infection Prevention and Control Technical and Clinical Hub

More...

Abstract

Background: The wearing of medical and non-medicaal masks by the general public in community settings is one intervention that is important for the reduction of SARS-COV-2 transmission, and has been the subject of considerable research, policy, advocacy and debate.  Several observational studies have used ecological (population-level) data to assess the effect of masks on transmission, hospitalization, and mortality at the region or community level.  

Methods: We undertook this systematic review to summarize the study designs, outcomes, and key quality indicators of using ecological data to evaluate the association between mask wearing and COVID-19 outcomes.  We searched the World Health Organization (WHO) COVID-19 global literature database up to 4 March 2021 for studies reporting the impact of mask use in community settings on outcomes related to SARS-COV-2 transmission using ecologic data.  

Findings: 21 articles were identified that analysed ecological data to assess the protective effect of policies mandating community mask wearing. All studies reported SARS-COV-2 benefits in terms of reductions in either the incidence, hospitalization, or mortality, or a combination of these outcomes. Few studies assessed compliance to mask wearing policies or controlled for the possible influence of other preventive measures such as hand hygiene and physical distancing, and information about compliance to these policies was lacking.  

Interpretation: Ecological studies have been cited as evidence to advocate for the adoption of universal masking policies. The studies summarized by this review suggest that community mask policies may reduce the population-level burden of SARS-CoV-2. Methodological limitations, in particular controlling for the actual practice of mask wearing and other preventive policies make it difficult to determine causality. There are several important limitations to consider for improving the validity of ecological data.

Funding Statement: None.

Declaration of Interests: None.

Suggested Citation

Ford, Nathan and Holmer, Haley K. and Chou, Roger and Villeneuve, Paul and Baller, April and Van Kerkhove, Maria and Allegranzi, Benedetta, Mask Use in Community Settings in the Context of COVID-19: A Systematic Review of Ecological Data. Available at SSRN: https://ssrn.com/abstract=3848524 or http://dx.doi.org/10.2139/ssrn.3848524

Nathan Ford (Contact Author)

World Health Organization - Guidelines Review Committee

Geneva
Switzerland

Haley K. Holmer

VA Portland Health Care System - Center to Improve Veteran Involvement in Care (CIVIC) ( email )

Palo Alto, CA 94304
United States

Roger Chou

Oregon Health and Science University ( email )

3181 S.W. Sam Jackson Park Rd.
Portland, OR 97201
United States

Paul Villeneuve

Carleton University - School of Mathematics and Statistics and Department of Neurosciences

3230 HERZBERG LABORATORIES
1125 Colonel By Drive
Ottawa, Ontario K1S 5B6
Canada

April Baller

World Health Organization - Health Emergency Programme ( email )

Congo, Democratic Republic of the (Zaire)

Maria Van Kerkhove

World Health Organization - Health Emergency Programme ( email )

Congo, Democratic Republic of the (Zaire)

Benedetta Allegranzi

World Health Organization - Infection Prevention and Control Technical and Clinical Hub ( email )

20 Avenue Appia
Geneva 27, CH-1211
Switzerland

Click here to go to TheLancet.com

Paper statistics

Abstract Views
2,612
Downloads
247
PlumX Metrics