Assessing factors associated with the COVID-19 risk in people with asthma

Date of ISAC Approval: 
12/06/2020
Lay Summary: 
Coronavirus disease 2019 (COVID-19) is an infection caused by the virus SARS-CoV-2, which first appeared in late 2019 in China. It has spread quickly since then, and on March 11th the World Health Organisation officially declared that the COVID-19 outbreak is a global pandemic. People with COVID-19 can have fever, cough, and breathing difficulties, often from pneumonia due to the virus. However, it seems unexpectedly there was much lower numbers of people with asthma – a long-term lung condition – in COVID-19 hospitalised patients in China, Italy. This is unexpected as virus often trigger asthma attacks and the 2009 flu pandemic asthma was a significant risk factor for people needing to be admitted to hospital. There are several thoughts on why asthma patients have less severe COVID-19 infection. It could be related to asthma medications or the type of inflammation that occurs in people with asthma. This study will measure how often, and how severe, asthma patients develop COVID-19 in the UK. By comparing to diseases with either similar treatment or similar inflammation, try to understand what the protective factors are.
Technical Summary: 
Three cohorts of patients with asthma, allergic rhinitis and chronic obstructive pulmonary disease will be drawn; the frequency and severity of COVID-19 will be measured in each cohort for each month in Feb-May 2020 and a matched general population cohort. Crude and standardised (age, gender) incidence will be calculated and stratified by inhaled corticosteroid (ICS) dose, eosinophil count and atopy; for each disease cohort. Poisson models will be used to compare rates between the asthma cohort and the two other patient cohorts and general population; adjusting for age, gender, BMI, socioeconomic status, smoking, inhaled medications and comorbidities. For each patient cohort, use multivariable Cox proportional hazards regression to assess the association between COVID-19 diagnosis and disease severity, ICS dose, eosinophil count and atopy. Linked data will be used for the outcome variable for hospitalised COVID-19 patients (HES) and death from COVID-19 (ONS). Compare incidence rates of asthma attacks in Feb-May2019 to Feb-Mary 2020; adjusting for confounders. Compare ICS prescriptions per patient in Feb-May2019 to Feb-Mary 2020.
Health Outcomes to be Measured: 
COVID-19 diagnosis (confirmed and suspected), asthma exacerbations and ICS use.
Collaborators: 

Chloe Bloom - Chief Investigator - Imperial College London
Chloe Bloom - Corresponding Applicant - Imperial College London

Linkages: 
HES A&E;HES Admitted;HES Outpatient;ONS;Patient IMD