Evidence map›Paper›PMID 34404718›Full record

SynthesisBMJ open2021

Do school closures and school reopenings affect community transmission of COVID-19? A systematic review of observational studies.

Sebastian Walsh, Avirup Chowdhury, Vickie Braithwaite, Simon Russell, Jack Michael Birch, Joseph L Ward, Claire Waddington, Carol Brayne, Chris Bonell, Russell M Viner and 1 more

Open access · goldAbstract readSystematic Review
PubMed Full text at PMC Publisher
In one paragraph

Synthesis in BMJ open, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 91 papers, 4 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
91citing papers in PubMed, 4 pooled it
10.7field-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

91 citing papers in PubMed, 4 syntheses or guidelines pooled it, 132 citations in OpenAlex.

  1. Measures implemented in the school setting to contain the COVID-19 pandemic.The Cochrane database of systematic reviews · 2024
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  3. Measures implemented in the school setting to contain the COVID-19 pandemicThe Cochrane database of systematic reviews · 2022
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31 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

11 authors at 3 institutions in 1 country.

Sebastian WalshCambridge Public Health, University of Cambridge, Cambridge, UK sjw261@medschl.cam.ac.uk.ORCID 0000-0001-8894-5006
Avirup ChowdhuryMRC Epidemiology Unit, University of Cambridge, Cambridge, UK.ORCID 0000-0001-9817-0603
Vickie BraithwaiteMRC Epidemiology Unit, University of Cambridge, Cambridge, UK.ORCID 0000-0002-3366-2903
Simon RussellPopulation, Policy & Practice Department, University College London Institute of Child Health, London, UK.
Jack Michael BirchMRC Epidemiology Unit, University of Cambridge, Cambridge, UK.ORCID 0000-0001-6292-1647
Joseph L WardPopulation, Policy & Practice Department, University College London Institute of Child Health, London, UK.
Claire WaddingtonDepartment of Medicine, University of Cambridge, Cambridge, UK.
Carol BrayneCambridge Public Health, University of Cambridge, Cambridge, UK.
Chris BonellLondon School of Hygiene and Tropical Medicine Faculty of Public Health and Policy, London, UK.ORCID 0000-0002-6253-6498
Russell M VinerPopulation, Policy & Practice Department, University College London Institute of Child Health, London, UK.ORCID 0000-0003-3047-2247
Oliver T MyttonMRC Epidemiology Unit, University of Cambridge, Cambridge, UK.ORCID 0000-0003-3218-9912
University of Cambridge · GBUniversity College London · GBLondon School of Hygiene & Tropical Medicine · GB

Funding

Medical Research Council MC_UU_00006/6Medical Research Council MC_UU_12015/4Medical Research Council MR/R00160X/1
6 · The paper itself

Abstract

objectivesTo systematically reivew the observational evidence of the effect of school closures and school reopenings on SARS-CoV-2 community transmission.

settingSchools (including early years settings, primary schools and secondary schools).

interventionSchool closures and reopenings. OUTCOME MEASURE: Community transmission of SARS-CoV-2 (including any measure of community infections rate, hospital admissions or mortality attributed to COVID-19).

methodsOn 7 January 2021, we searched PubMed, Web of Science, Scopus, CINAHL, the WHO Global COVID-19 Research Database, ERIC, the British Education Index, the Australian Education Index and Google, searching title and abstracts for terms related to SARS-CoV-2 AND terms related to schools or non-pharmaceutical interventions (NPIs). We used the Cochrane Risk of Bias In Non-randomised Studies of Interventions tool to evaluate bias.

resultsWe identified 7474 articles, of which 40 were included, with data from 150 countries. Of these, 32 studies assessed school closures and 11 examined reopenings. There was substantial heterogeneity between school closure studies, with half of the studies at lower risk of bias reporting reduced community transmission by up to 60% and half reporting null findings. The majority (n=3 out of 4) of school reopening studies at lower risk of bias reported no associated increases in transmission.

conclusionsSchool closure studies were at risk of confounding and collinearity from other non-pharmacological interventions implemented around the same time as school closures, and the effectiveness of closures remains uncertain. School reopenings, in areas of low transmission and with appropriate mitigation measures, were generally not accompanied by increasing community transmission. With such varied evidence on effectiveness, and the harmful effects, policymakers should take a measured approach before implementing school closures; and should look to reopen schools in times of low transmission, with appropriate mitigation measures.

Indexed as

COVID-19AustraliaBiasHumansSARS-CoV-2SchoolsCOVID-19epidemiologypublic health

Identifiers

PMID34404718
PMCPMC8375447
OpenAlexW3196044496

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC
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.