Asthma phenotypes and COVID-19 risk: a population-based observational study
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Published version
Author(s)
Bloom, Chloe I
Cullinan, Paul
Wedzicha, Jadwiga A
Type
Journal Article
Abstract
Rationale: Studies have suggested some asthma patients are at risk of severe COVID-19, but they have had limited data on asthma phenotype and have not considered if risks are specific to COVID-19. Objectives: Determine the effect of asthma phenotype on three levels of COVID-19 outcomes. Compare hospitalisation rates to influenza and pneumonia. Methods: Electronic medical records were used to identify asthma patients and match them to the general population. Patient-level data were linked to Public Health England SARS-CoV-2 test data, hospital, and mortality data. Asthma was phenotyped by medication, exacerbation history, and type-2 inflammation. The risk of each outcome, adjusted for major risk factors, was measured using Cox regression. Measurements and Main Results: 434,348 asthma and 748,327 matched patients were included. All asthma patients had a significantly increased risk of a GP-diagnosis of COVID-19. Asthma with regular inhaled corticosteroid (ICS) use (HR=1.27, 95%CI=1.01-1.61), intermittent ICS + add-on asthma medication use (HR=2.00, 95%CI=1.43-2.79), regular ICS + add-on use (HR=1.63, 95 CI=1.37-1.94), or with frequent exacerbations (HR=1.82, 95% CI=1.34-2.47) was significantly associated with hospitalisation. These phenotypes were significantly associated with influenza and pneumonia hospitalisations. Only patients with regular ICS + add-on asthma therapy (HR=1.70, 95%CI=1.27-2.26) or frequent exacerbations (HR=1.66, 95%CI=1.03-2.68) had a significantly higher risk of ICU admission or death. Atopy and blood eosinophil count were not associated with severe COVID-19 outcomes. Conclusions: More severe asthma was associated with more severe COVID-19 outcomes, but type-2 inflammation was not. The risk of COVID-19 hospitalisation appeared to be similar to the risk with influenza or pneumonia.
Date Issued
2021-10-20
Date Acceptance
2021-10-19
Citation
American Journal of Respiratory and Critical Care Medicine, 2021, 205 (1), pp.36-45
ISSN
1073-449X
Publisher
American Thoracic Society
Start Page
36
End Page
45
Journal / Book Title
American Journal of Respiratory and Critical Care Medicine
Volume
205
Issue
1
Copyright Statement
© 2021 by the American Thoracic Society. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Sponsor
Imperial College London
Identifier
https://www.atsjournals.org/doi/10.1164/rccm.202107-1704OC
Subjects
COVID-19
allergic rhinitis
asthma
disease severity
influenza
Respiratory System
11 Medical and Health Sciences
Publication Status
Published
Date Publish Online
2021-10-20