The evidence suggests that school closures may make very little difference in the prevention of severe acute respiratory syndrome and low benefits in the prevention of endemic human coronavirus or influenza outbreaks. There is a lack of policy-relevant data on implementation of school social distancing during coronavirus outbreaks. However, data from influenza outbreaks showing benefits of school closures cannot necessarily be applied to coronavirus disease-2019 (COVID-19). Policymakers need to be aware of misleading evidence when proposing or implementing national or regional school closures for COVID-19. The review had significant methodological weaknesses, so the findings should be interpreted with caution. Further studies are warranted to look into other less disruptive school social distancing interventions.
Overall summary High risk of bias in the review
A limited number of databases were searched. Chinese studies with no translation were excluded. Three reviewers were involved in the title/abstract screening and one reviewer was involved in full-text screening, this was considered inappropriate. Only one author was involved in the extraction of articles. There were insufficient study details available to allow the reader to interpret the results. The methodological quality of included studies was not assessed.
|A. Did the interpretation of findings address all of the concerns identified in Domains 1 to 4?||Probably no|
|B. Was the relevance of identified studies to the review's research question appropriately considered?||Probably yes|
|C. Did the reviewers avoid emphasizing results on the basis of their statistical significance?||Probably yes|
|Risk of bias in the review||High|
|Number of studies||13|
|Number of participants||NR|
|Last search date||9 March 2020|
|Objective||To determine the use and effectiveness of school closure and other school social distancing practices on infection during coronavirus outbreaks.|
|Population||School or nursery children.
Studies in university-specific settings and addressing other viruses were excluded.
|Interventions||School closure, school social distancing practices.|
|Outcome||Transmission, infection of coronavirus outbreaks (severe acute respiratory syndrome, Middle East respiratory syndrome coronavirus and coronavirus disease-2019).|
|Study design||Qualitative research, modelling studies.
Opinion pieces, systematic reviews, epidemiological studies were excluded.
Two studies reported that school closures made very little difference to the prevention of severe acute respiratory syndrome (SARS), when schools were closed approximately 6 weeks after the beginning of the outbreak remaining closed for over 2 months or when school closures occurred after the rate had dropped below 1. One study had no recorded transmission of SARS in schools during the outbreak. One early modelling study of a SARS-like illness in school children concluded that a school closure policy would reduce the outbreaks rate by 12 to 41% depending on the proportion of between-household mixing that occurred during school hours. Another modelling study of the transmission of SARS in hospitals and in elementary school classrooms reported that a single case of SARS would infect 2.6 secondary cases on average in a population from the hospital and less than 1 secondary infection per case in a school classroom.
One study reported that a 5-day closure of nearly all schools in a metropolitan area resulted in a 5.6% reduction of endemic human coronavirus infections, 7.6% of influenza H1N1 and 3.1% of influenza H3N2 virus transmission (1 study). There was no data reported on the relative contribution of school closure to the control of transmission of coronavirus disease-2019.
One study observed that healthcare workers experienced substantial personal dilemmas in balancing work and family commitments, particularly relating to child-care needs if schools or child-care are closed.
The research objective was clearly stated. Eligibility criteria were well described and appeared appropriate to address the present review question. No restrictions were applied to eligibility criteria based on study characteristics and sources of information.
|1.1 Did the review adhere to pre-defined objectives and eligibility criteria?||Probably yes|
|1.2 Were the eligibility criteria appropriate for the review question?||Probably yes|
|1.3 Were eligibility criteria unambiguous?||Probably yes|
|1.4 Were all restrictions in eligibility criteria based on study characteristics appropriate (e.g. date, sample size, study quality, outcomes measured)?||Probably yes|
|1.5 Were any restrictions in eligibility criteria based on sources of information appropriate (e.g. publication status or format, language, availability of data)?||Probably yes|
|Concerns regarding specification of study eligibility criteria||Low|
Studies were identified through searching PubMed, WHO Global Research Database, preprint server medRxi databases. The reference lists of retrieved articles were handsearched for additional relevant studies. The search terms and search strategy were reported and appeared to be adequate. There were no restrictions imposed based on date or publication format. Chinese studies with no translation were excluded. Three reviewers were involved in the title/abstract screening and one reviewer was involved in full-text screening and this was considered inappropriate.
|2.1 Did the search include an appropriate range of databases/electronic sources for published and unpublished reports?||Probably no|
|2.2 Were methods additional to database searching used to identify relevant reports?||Probably yes|
|2.3 Were the terms and structure of the search strategy likely to retrieve as many eligible studies as possible?||Probably yes|
|2.4 Were restrictions based on date, publication format, or language appropriate?||Probably no|
|2.5 Were efforts made to minimise error in selection of studies?||Probably no|
|Concerns regarding methods used to identify and/or select studies||High|
Only one author was involved in the extraction of articles. There were insufficient study details available to allow the reader to interpret the results. Relevant study results appear to have been extracted. The methodological quality of included studies was not assessed.
|3.1 Were efforts made to minimise error in data collection?||Probably no|
|3.2 Were sufficient study characteristics considered for both review authors and readers to be able to interpret the results?||Probably no|
|3.3 Were all relevant study results collected for use in the synthesis?||Probably yes|
|3.4 Was risk of bias (or methodological quality) formally assessed using appropriate criteria?||Probably no|
|3.5 Were efforts made to minimise error in risk of bias assessment?||Probably no|
|Concerns regarding methods used to collect data and appraise studies||High|
The synthesis included all relevant studies and was appropriate. A narrative synthesis was performed to summarise the findings. Bias in primary studies was not addressed while interpreting the findings.
|4.1 Did the synthesis include all studies that it should?||Probably yes|
|4.2 Were all pre-defined analyses reported or departures explained?||Probably yes|
|4.3 Was the synthesis appropriate given the degree of similarity in the research questions, study designs and outcomes across included studies?||Probably yes|
|4.4 Was between-study variation minimal or addressed in the synthesis?||Probably yes|
|4.5 Were the findings robust, e.g. as demonstrated through funnel plot or sensitivity analyses?||Probably yes|
|4.6 Were biases in primary studies minimal or addressed in the synthesis?||Probably no|
|Concerns regarding synthesis and findings||High|
Background: COVID-19 was declared a pandemic by the WHO on 12 March 2020 and UNESCO reported that day that 49 countries had implemented national or subnational school closures. Evidence for the effectiveness for school closures comes almost entirely from influenza outbreaks, where transmission tends to be driven by children. It is unknown whether school measures are effective in coronavirus outbreaks e.g. due to SARS, or MERS and COVID-19. Methods: We undertook a rapid systematic review of 2 electronic databases and a preprint server to identify what is known about the effectiveness of school closure and other social school social distancing practices on infection during coronavirus outbreaks. Results: We identified 498 articles, of which 13 are included in this review (9 published; 4 preprint articles considered sufficient quality to include). All published papers concerned the 2003 SARS outbreak and 3 preprints concerned COVID-19. School closures were deployed rapidly across China and Hong Kong for COVID-19, however there are no data on the relative contribution of school closure to control of transmission. Data from the SARS outbreak in China, Hong Kong and Singapore suggest that school transmission played no significant role in the outbreak and that school closures did not contribute to control of the epidemic. Modelling studies of SARS produced conflicting results. Conclusions: Available evidence is consistent with a broad range of impacts of school closures, from little benefit for reducing transmission through to more substantial effects. Yet the economic costs and potential harms of school closure are very high. Data from influenza outbreaks suggests that school closures have low benefits in outbreaks with high transmissibility as with COVID-19. Policymakers need to be aware of the equivocal evidence when proposing or implementing school closures for COVID-19, and consideration should be given to other less disruptive social distancing interventions in schools.