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.
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.
COVID-19 diagnosis (confirmed and suspected), asthma exacerbations and ICS use
Chloe Bloom - Chief Investigator - Imperial College London
Chloe Bloom - Corresponding Applicant - Imperial College London
Ernie Wong - Collaborator - Imperial College Healthcare NHS Trust
Katherine Hickman - Collaborator - NHS England
Paul Cullinan - Collaborator - Imperial College London
Sarah Elkin - Collaborator - Imperial College Healthcare NHS Trust
Wisia Wedzicha - Collaborator - Imperial College London
CHESS (Hospitalisation in England Surveillance System);HES Accident and Emergency;HES Admitted Patient Care;HES Outpatient;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;SGSS (Second Generation Surveillance System);COVID-19 Linkages