Cross-sectional case-control studies (Blue)
The objective of this matched cohort study was to establish whether there is any change in mortality from infection with a new variant of SARS-CoV-2 , designated a variant of concern (VOC-202012/1) in December 2020, compared with circulating SARS-CoV-2 variants. 54 906 matched pairs of participants who tested positive for SARS-CoV-2 in community based (pillar 2) COVID-19 testing centres in the UK between 1 October 2020 and 29 January 2021, followed-up until 12 February 2021 were assessed. Participants were matched on age, sex, ethnicity, index of multiple deprivation, lower tier local authority region, and sample date of positive specimens, and differed only by detectability of the spike protein gene using the TaqPath assay. Death within 28 days of the first positive SARS-CoV-2 test result represented the main outcome measure. The mortality hazard ratio associated with infection with VOC-202012/1 compared with infection with previously circulating variants was 1.64 (95% confidence interval 1.32 to 2.04) in patients who tested positive for COVID-19 in the community. In this comparatively low risk group, this represents an increase in deaths from 2.5 to 4.1 per 1000 detected cases. The authors concluded that the probability that the risk of mortality is increased by infection with VOC-202012/01 is high. If this finding is generalizable to other populations, infection with VOC-202012/1 has the potential to cause substantial additional mortality compared with previously circulating variants.
Challen R, et al. Risk of mortality in patients infected with SARS-CoV-2 variant of concern 202012/1: matched cohort study. BMJ. 2021 Mar 9;372:n579. doi: 10.1136/bmj.n579