Risk of severe Covid-19 from asthma and other respiratory diseases is only modestly increased, shows new analysis

1 April 2021

People with asthma have only a modestly increased risk of developing severe Covid-19 and requiring admission to hospital from the illness, finds an analysis of 8.3 million electronic health care records in England led by University of Oxford researchers.

Published today in The Lancet Respiratory Medicine, the study examined routine patient data collected between January 2020 to April 2020 to generate risk assessments for severe Covid-19 in people with chronic respiratory diseases. Unlike previous studies of people hospitalised with Covid-19, which suggest large increases in risk associated with underlying respiratory disease, this analysis demonstrates that the risk of severe Covid-19 is only modestly raised over the risk in people without such conditions.

The analysis reviewed several respiratory diseases and included data from 1.09 million people with asthma, 193,520 people with chronic obstructive pulmonary disease and 5,677 people with other interstitial lung disease. It compared the risks in these groups to 7 million people without respiratory diseases.

When adjusted for age, sex, demographic factors, underlying health conditions and compared with those without respiratory diseases, people with active asthma and severe asthma were at 26% and 29% higher relative risk of hospital admission with Covid-19, respectively, and around 30% higher relative risk of admission to intensive care.

There was no evidence that asthma was associated with an increased absolute risk of death from Covid-19, and the risks appeared similar for all ethnicities.

Having chronic obstructive pulmonary disease (COPD) was associated with a 50% increased risk of hospitalisation and 54% increased risk of death from Covid-19, which was higher in those with white ethnicity.

In patients with interstitial disease, a group of less common lung diseases which cause scarring of the lung tissue, the analysis shows a 30–50% increased relative risk of developing severe Covid-19 requiring hospital admission or leading to death. Patients in this group are currently advised to shield.

Though a concern for many, the risk of long-Covid in people with respiratory disease was not determined in this study.

Lead researcher Professor Paul Aveyard, a general practitioner and Professor of Behavioural Medicine in the University of Oxford’s Nuffield Department of Primary Care Health Sciences said: ‘At the start of the pandemic, the assumption that pre-existing respiratory disease would lead to an increased risk of serious Covid-19 illness was reasonable. Covid-19 has quite rightly caused much anxiety in people with respiratory disease and while our results do show this group are at higher risk from developing severe Covid-19, when you put this into context with other known risk factors for hospitalisation, the relative risk for those with chronic respiratory disease are lower than the risks from being male or having diabetes, and are a small fraction of the everyday risk of death from any cause.

‘Our analysis suggests that the risk of hospital admission from severe Covid-19 in a person with asthma is equivalent to the risk for people without asthma who are three to five years older. For people with COPD or interstitial lung disease, their risk would be equivalent to the risk for people without these conditions who are seven to eight years older.

‘As data has continued to emerge, it is right to challenge the assumptions that respiratory disease is a severe risk and revisit the guidance. Based on the analysis we’ve conducted, people with chronic asthma can be reassured that while they are unfortunately at a modestly increased risk of hospitalisation from Covid-19, their risk of death is no different to those without asthma.’

The study also provides further evidence that the use of inhaled corticosteroids in those with airways diseases is not associated with substantial increased risk of severe Covid-19, but neither does it appear to be linked to reduced risk.

In their paper, the researchers state that it is possible that people with chronic respiratory diseases may have behaved differently during the early stages of the pandemic to avoid social contact, because they expected to be at a higher risk of severe disease, or because they were shielding, and so the true risk of severe Covid-19 for people with respiratory disease in this study may be underestimated.

The researchers were funded by the National Institute for Health Research Oxford Biomedical Research Centre and the Wellcome Trust, and the data for this study was obtained through the QResearch database of electronic healthcare records.

Notes for editors:

For interview requests, contact: Professor Paul Aveyard, paul.aveyard@phc.ox.ac.uk

For all other enquiries, contact Dan Richards-Doran, Nuffield Department of Primary Care Health Sciences, University of Oxford dan.richards-doran@phc.ox.ac.uk

Association between pre-existing respiratory disease and its treatment, and severe COVID-19: a population cohort study Paul Aveyard, Min Gao, Nicola Lindson et al. Lancet Respir Med 2021 Post embargo link to published article: http://www.thelancet.com/journals/lanres/article/PIIS2213-2600(21)00095-3/fulltext

About the University of Oxford
Oxford University has been placed number 1 in the Times Higher Education World University Rankings for the fifth year running, and at the heart of this success is our ground-breaking research and innovation. Oxford is world-famous for research excellence and home to some of the most talented people from across the globe. Our work helps the lives of millions, solving real-world problems through a huge network of partnerships and collaborations. The breadth and interdisciplinary nature of our research sparks imaginative and inventive insights and solutions.

Oxford University’s Medical Sciences Division is one of the largest biomedical research centres in Europe, with over 2,500 people involved in research and more than 2,800 students. The University is rated the best in the world for medicine and life sciences, and it is home to the UK’s top-ranked medical school. It has one of the largest clinical trial portfolios in the UK and great expertise in taking discoveries from the lab into the clinic. Partnerships with the local NHS Trusts enable patients to benefit from close links between medical research and healthcare delivery.

Within the division, the Nuffield Department of Primary Care Health Sciences is the largest, top-ranked centre for academic primary care in the UK and leads world-class research and training to rethink the way healthcare is delivered in general practice and other primary care settings. The department’s main research focus on the prevention, early diagnosis and management of common illness, bringing together academics from many different backgrounds to work together to produce benefits for the NHS, for populations and for patients. www.phc.ox.ac.uk

About the National Institute for Health Research (NIHR)
The National Institute for Health Research (NIHR) is the nation's largest funder of health and care research. The NIHR:

  • Funds, supports and delivers high quality research that benefits the NHS, public health and social care.
  • Engages and involves patients, carers and the public in order to improve the reach, quality and impact of research.
  • Attracts, trains and supports the best researchers to tackle the complex health and care challenges of the future.
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The NIHR was established in 2006 to improve the health and wealth of the nation through research, and is funded by the Department of Health and Social Care. In addition to its national role, the NIHR commissions applied health research to benefit the poorest people in low- and middle-income countries, using Official Development Assistance funding.
This work uses data provided by patients and collected by the NHS as part of their care and support and would not have been possible without access to this data. The NIHR recognises and values the role of patient data, securely accessed and stored, both in underpinning and leading to improvements in research and care. www.nihr.ac.uk/patientdata