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.
| Original language | English |
|---|---|
| Article number | n1412 |
| Journal | British Medical Journal |
| Volume | 373 |
| DOIs | |
| Publication status | Published - 15 Jun 2021 |
Bibliographical note
Funding Information: This research was funded by the Medical Research Council (TN, DDA, AMP; Unit programme number MC_UU_00002/11, SRS Unit programme number MC_UU_00002/10); and via a grant from the MRC UKRI/DHSC NIHR COVID-19 rapid response call (TN, AC, DDA, AMP; grant ref MC_PC_19074). This research was also supported by the NIHR Cambridge Biomedical Research Centre. The funders had no role in considering the study design or in the collection, analysis, or interpretation of data, the writing of the report, or the decision to submit the article for publication. 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.Open Access: This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution (CC BY 4.0) license, which permits others to distribute, remix, adapt and build upon this work, for commercial use, provided the original work is properly cited. See: http://creativecommons.org/licenses/by/4.0/.
Publisher Copyright: © 2019 Author(s) (or their employer(s)).
Citation: Nyberg T, Twohig K A, Harris R J, Seaman S R, Flannagan J, Allen H et al. Risk of hospital admission for patients with SARS-CoV-2 variant B.1.1.7: cohort analysis BMJ 2021; 373 :n1412
DOI:10.1136/bmj.n1412