Evidence map›Paper›PMID 32497510›Full record

SynthesisLancet (London, England)2020

Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis.

Derek K Chu, Elie A Akl, Stephanie Duda, Karla Solo, Sally Yaacoub, Holger J Schünemann, COVID-19 Systematic Urgent Review Group Effort (SURGE) study authors

Registry-linked trialOpen access · hybridAbstract readMeta-AnalysisSystematic Review
PubMed Full text at PMC Publisher
In one paragraph

Synthesis in Lancet (London, England), 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT05102708 (Study of COVID-19 Prognostic Factors in Hospitalized Patients), which is not on this map. Cited by 1,927 papers, 9 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
1,927citing papers in PubMed, 9 pooled it
454.9field-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.

NCT05102708 completednot on this mapstarted 2021, after this paper: background citation

Study of COVID-19 Prognostic Factors in Hospitalized Patients

TypeobservationalSponsorFundació Institut de Recerca de l'Hospital de la Santa Creu i Sant PauRan2021 to 2022Enrolled3,725ConditionsCOVID-19ArmsPrognostic factors of severe COVID-19
3 · Its place in the literature

Who cites it

1,927 citing papers in PubMed, 9 syntheses or guidelines pooled it, 4,058 citations in OpenAlex.

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1,867 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

7 authors at 4 institutions in 3 countries.

Derek K ChuDepartment of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, ON, Canada; Department of Medicine, McMaster University, Hamilton, ON, Canada; The Research Institute of St Joe's Hamilton, Hamilton, ON, Canada.
Elie A AklDepartment of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, ON, Canada; Department of Internal Medicine, American University of Beirut, Beirut, Lebanon; Clinical Research Institute, American University of Beirut, Beirut, Lebanon.
Stephanie DudaDepartment of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, ON, Canada.
Karla SoloDepartment of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, ON, Canada.
Sally YaacoubClinical Research Institute, American University of Beirut, Beirut, Lebanon.
Holger J SchünemannDepartment of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, ON, Canada; Department of Medicine, McMaster University, Hamilton, ON, Canada; Michael G DeGroote Cochrane Canada and GRADE Centres, Hamilton, ON, Canada. Electronic address: schuneh@mcmaster.ca.
COVID-19 Systematic Urgent Review Group Effort (SURGE) study authors
Impact · CAMcMaster University · CAAmerican University of Beirut · LBSamsung (China) · CN

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19 and is spread person-to-person through close contact. We aimed to investigate the effects of physical distance, face masks, and eye protection on virus transmission in health-care and non-health-care (eg, community) settings.

methodsWe did a systematic review and meta-analysis to investigate the optimum distance for avoiding person-to-person virus transmission and to assess the use of face masks and eye protection to prevent transmission of viruses. We obtained data for SARS-CoV-2 and the betacoronaviruses that cause severe acute respiratory syndrome, and Middle East respiratory syndrome from 21 standard WHO-specific and COVID-19-specific sources. We searched these data sources from database inception to May 3, 2020, with no restriction by language, for comparative studies and for contextual factors of acceptability, feasibility, resource use, and equity. We screened records, extracted data, and assessed risk of bias in duplicate. We did frequentist and Bayesian meta-analyses and random-effects meta-regressions. We rated the certainty of evidence according to Cochrane methods and the GRADE approach. This study is registered with PROSPERO, CRD42020177047.

findingsOur 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; p

interpretationThe 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.

fundingWorld Health Organization.

Indexed as

BetacoronavirusCommunicable Disease ControlEye Protective DevicesMasksSocial IsolationCoronavirus InfectionsCOVID-19HumansPandemicsPhysical DistancingPneumonia, ViralSARS-CoV-2

Identifiers

PMID32497510
PMCPMC7263814
OpenAlexW3032742287

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

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.