Characterizing the association between asthma and clinical outcomes in emergency department patients with symptomatic COVID-19

Few studies have investigated the risks of developing intubation and death in patients seen in the ED with COVID-19 and pre-existing asthma. We conducted a retrospective cohort study using data from the Canadian COVID-19 Emergency Department Rapid Response Network (CCEDRRN) from March 1st, 2020, to December 31st, 2021. Inclusion criteria were age ≥18 and a positive SARS CoV-2 test. The primary outcome was a composite of intubation or death, and the secondary outcome was severe COVID-19 as defined by the World Health Organization. Multivariable modified Poisson regression was used to assess the association between asthma and outcomes, adjusted for possible confounding. Out of 38,139 patients, 2,826 (7.41%) had asthma, and 17.1% were using inhaled corticosteroids (ICS). The study found no significant evidence suggesting an association between asthma and intubation or death in the hospital (RR: 0.97; 95% CI: 0.86, 1.1). The highest risk group for the primary outcome was patients aged 80+ years (RR: 10.54; 95% CI: 7.01, 15.85), compared to the reference group 18-29 years. Users of ICS agents had a slightly higher risk of the primary outcome compared to non-ICS users (RR: 1.12; 95% CI: 1.01, 1.25). Clinical Trial Registration ClinicalTrials.gov NCT04702945