The impact of local and national restrictions in response to COVID-19 on social contacts in the UK: a longitudinal natural experiment.

Status: Paper under peer review | First online: 19-10-2020 | Last update: 19-10-2020

This study has not yet been peer reviewed.

Background

The United Kingdom’s (UK) COVID-19 response transitioned from a national lockdown to more localised interventions with less restrictive national measures. In September 2020, the UK imposed three national restrictions; the Rule of Six, pubs and restaurants closing at 10pm, and encouraging individuals to work from home (WFH). The impact of these local and national restrictions on transmission is unclear and difficult to estimate. In this paper, we used paired measurements of individuals’ contacts from the national CoMix survey to test whether restrictions altered epidemiologically relevant contacts and estimate these effects.

Methods

We compared paired measures on setting-specific contacts before and after each restriction started and tested for differences using paired permutation tests on the mean change in contacts and the proportion of individuals decreasing their contacts.

Results

Among 3,222 individuals, we found strong evidence (p<0.001) that following the rule of six more people reduced their non-work and non-home contacts than expected by chance, though the data were consistent (p=0.827) with an absolute effect of zero. For 1,868 participants, the data were consistent with no change (p=0.18) in other contacts due to 10pm closure. For 639 employed adults, the data suggested (p=0.001) more people reduced their work contacts than expected by chance but results were consistent (p=0.213) with an absolute effect of zero. Among 293 individuals, there was evidence (p=0.01) that following local restrictions more participants had reduced their contacts. On average, participants reported 0.74 (0.16 to 1.55) fewer non-work and non-school contacts than before the restrictions (p=0.005).

Conclusions

We determine that the rule of six and encouraging people to WFH, has seen the average person reduce contacts but these reductions are likely small. There was little suggestion that 10pm closure has affected the number of contacts that participants make outside home, work and school. In contrast to national restrictions, there was a strong suggestion that local restrictions reduced the number of contacts individuals make outside of work and school, though again, this effect was small in comparison to the national lockdown.

CoMix restrictions full report