Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Jun 15:373:n1412.
doi: 10.1136/bmj.n1412.

Risk of hospital admission for patients with SARS-CoV-2 variant B.1.1.7: cohort analysis

Tommy Nyberg  1 , Katherine A Twohig  2 , Ross J Harris  3 , Shaun R Seaman  4 , Joe Flannagan  2 , Hester Allen  2 , Andre Charlett  3 , Daniela De Angelis  4   3 , Gavin Dabrera  2 , Anne M Presanis  4
Affiliations

Risk of hospital admission for patients with SARS-CoV-2 variant B.1.1.7: cohort analysis

Tommy Nyberg et al. BMJ. .

Abstract

Objective: To evaluate the relation between diagnosis of covid-19 with SARS-CoV-2 variant B.1.1.7 (also known as variant of concern 202012/01) and the risk of hospital admission compared with diagnosis with wild-type SARS-CoV-2 variants.

Design: Retrospective cohort analysis.

Setting: Community based SARS-CoV-2 testing in England, individually linked with hospital admission data.

Participants: 839 278 patients with laboratory confirmed covid-19, of whom 36 233 had been admitted to hospital within 14 days, tested between 23 November 2020 and 31 January 2021 and analysed at a laboratory with an available TaqPath assay that enables assessment of S-gene target failure (SGTF), a proxy test for the B.1.1.7 variant. Patient data were stratified by age, sex, ethnicity, deprivation, region of residence, and date of positive test.

Main outcome measures: Hospital admission between one and 14 days after the first positive SARS-CoV-2 test.

Results: 27 710 (4.7%) of 592 409 patients with SGTF variants and 8523 (3.5%) of 246 869 patients without SGTF variants had been admitted to hospital within one to 14 days. The stratum adjusted hazard ratio of hospital admission was 1.52 (95% confidence interval 1.47 to 1.57) for patients with covid-19 infected with SGTF variants, compared with those infected with non-SGTF variants. The effect was modified by age (P<0.001), with hazard ratios of 0.93-1.21 in patients younger than 20 years with versus without SGTF variants, 1.29 in those aged 20-29, and 1.45-1.65 in those aged ≥30 years. The adjusted absolute risk of hospital admission within 14 days was 4.7% (95% confidence interval 4.6% to 4.7%) for patients with SGTF variants and 3.5% (3.4% to 3.5%) for those with non-SGTF variants.

Conclusions: The results suggest that the risk of hospital admission is higher for people infected with the B.1.1.7 variant compared with wild-type SARS-CoV-2, likely reflecting a more severe disease. The higher severity may be specific to adults older than 30 years.

PubMed Disclaimer

Conflict of interest statement

Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf and declare: support for the submitted work from the Medical Research Council and NIHR Cambridge Biomedical Research Centre; GD’s employer, Public Health England, has received funding from GlaxoSmithKline for a research project related to seasonal influenza and antiviral treatment; this project preceded and had no relation to covid-19, and GD had no role in and received no funding from the project; no other relationships or activities that could appear to have influenced the submitted work.

Figures

Fig 1
Fig 1
Cumulative risk of hospital admission within 1-14 days after positive SARS-CoV-2 test, by age group. Risks were estimated with Cox regression stratified by S-gene target failure (SGTF) status and age group, adjusted for sex, index of multiple deprivation fifth, ethnicity, region of residence, and calendar week (potential confounders set to mean covariate levels)
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. PANGO lineages. grinch: global report investigating novel coronavirus haplotypes: B.1.1.7. 2021. https://cov-lineages.org/global_report_B.1.1.7.html.
    1. Public Health England. Investigation of variants of concern: technical briefing. 2021. https://www.gov.uk/government/publications/investigation-of-novel-sars-c....
    1. UK Government Prime Minister’s Office. Prime Minister announces national lockdown. 2021. https://www.gov.uk/government/news/prime-minister-announces-national-loc....
    1. Volz E, Mishra S, Chand M, et al. COVID-19 Genomics UK (COG-UK) consortium . Assessing transmissibility of SARS-CoV-2 lineage B.1.1.7 in England. Nature 2021;593:266-9. 10.1038/s41586-021-03470-x. - DOI - PubMed
    1. Davies NG, Abbott S, Barnard RC, et al. CMMID COVID-19 Working Group. COVID-19 Genomics UK (COG-UK) Consortium . Estimated transmissibility and impact of SARS-CoV-2 lineage B.1.1.7 in England. Science 2021;372:eabg3055. 10.1126/science.abg3055. - DOI - PMC - PubMed

Publication types

MeSH terms