Evaluating the impacts of tiered restrictions introduced in England, during October and December 2020 on COVID-19 cases: a synthetic control study

Zhang, Xingna ORCID: 0000-0002-8849-2112, Owen, Gwilym, Green, Mark A ORCID: 0000-0002-0942-6628, Buchan, Iain ORCID: 0000-0003-3392-1650 and Barr, Ben ORCID: 0000-0002-4208-9475 (2022) Evaluating the impacts of tiered restrictions introduced in England, during October and December 2020 on COVID-19 cases: a synthetic control study. BMJ OPEN, 12 (4). e054101-.

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Official URL: http://dx.doi.org/10.1136/bmjopen-2021-054101

Abstract

<h4>Objectives</h4>To analyse the impact on SARS-CoV-2 transmission of tier 3 restrictions introduced in October and December 2020 in England, compared with tier 2 restrictions. We further investigate whether these effects varied between small areas by deprivation.<h4>Design</h4>Synthetic control analysis.<h4>Setting</h4>We identified areas introducing tier 3 restrictions in October and December, constructed a synthetic control group of places under tier 2 restrictions and compared changes in weekly infections over a 4-week period. Using interaction analysis, we estimated whether this effect varied by deprivation and the prevalence of a new variant (B.1.1.7).<h4>Interventions</h4>In both October and December, no indoor between-household mixing was permitted in either tier 2 or 3. In October, no between-household mixing was permitted in private gardens and pubs and restaurants remained open only if they served a 'substantial meal' in tier 3, while in tier 2 meeting with up to six people in private gardens were allowed and all pubs and restaurants remained open. In December, in tier 3, pubs and restaurants were closed, while in tier 2, only those serving food remained open. The differences in restrictions between tier 2 and 3 on meeting outside remained the same as in October.<h4>Main outcome measure</h4>Weekly reported cases adjusted for changing case detection rates for neighbourhoods in England.<h4>Results</h4>Introducing tier 3 restrictions in October and December was associated with a 14% (95% CI 10% to 19%) and 20% (95% CI 13% to 29%) reduction in infections, respectively, compared with the rates expected with tier 2 restrictions only. The effects were similar across levels of deprivation and by the prevalence of the new variant.<h4>Conclusions</h4>Compared with tier 2 restrictions, additional restrictions in tier 3 areas in England had a moderate effect on transmission, which did not appear to increase socioeconomic inequalities in COVID-19 cases.

Item Type:	Article
Uncontrolled Keywords:	COVID-19, health policy, public health
Divisions:	Faculty of Health and Life Sciences Faculty of Health and Life Sciences > Institute of Population Health Faculty of Science and Engineering > School of Environmental Sciences
Depositing User:	Symplectic Admin
Date Deposited:	14 Apr 2022 09:10
Last Modified:	18 Jan 2023 21:05
DOI:	10.1136/bmjopen-2021-054101
Open Access URL:	https://bmjopen.bmj.com/content/12/4/e054101
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3152892