Asthma not associated with increased hospitalization in patients with COVID-19

Patients with asthma were not more likely to be hospitalized due to COVID-19 compared with patients without asthma, according to new data published in The Journal of Allergy and Clinical Immunology.

This finding comes despite a higher prevalence of patients with asthma in the study cohort than would be expected, given the estimates of asthma prevalence in the United States, according to the researchers.

“We would usually expect for asthmatic patients to have worse outcomes, as viral illness often can set off asthma exacerbations,” Anju T. Peters, MD, MSCI, FAAAI, director of clinical research in the division of allergy/immunology and otolaryngology at Northwestern University Feinberg School of Medicine, said in a press release.

Researchers conducted a retrospective study across 10 U.S. hospitals affiliated with Northwestern Medicine via automated chart review to examine the prevalence of asthma and comorbidities in patients with COVID-19. Of the identified 1,526 patients with COVID-19 (53% female, 55.3% aged 40 to 69 years), 220 (14.4%) had asthma.

The researchers used two models to assess asthma as a risk factor for hospitalization in patients with COVID-19. Results showed no significant difference in risk for hospitalization between patients with asthma and those without, after adjustment for baseline age, sex and race/ethnicity (RR = 1.01; 95% CI, 0.83-1.24). Moreover, the relative risk for hospitalization was not different between patients with asthma and those without, after adjustment for risk factors including smoking, obesity, coronary artery disease, diabetes, hypertension, obstructive sleep apnea, rhinosinusitis, allergic rhinitis and immunodeficiency (RR = 0.96; 95% CI, 0.77-1.19).

The prevalence of many comorbidities, including obesity, hypertension, sleep apnea, COPD and gastroesophageal reflux disease, was higher in patients with asthma and COVID-19 compared with patients with COVID-19 but no asthma. However, these comorbidities did not translate to a higher rate of hospitalization in patients with asthma and COVID-19, the researchers reported.

More than half (52%) of patients with asthma and COVID-19 were not prescribed inhaled corticosteroids (ICS) or ICS/long-acting beta agonists (LABA) at time of diagnosis. The researchers found that risk for hospitalization was not significantly greater for patients with asthma and COVID-19 prescribed these medications compared with those not using these medications (model 1: RR = 1.22; 95% CI, 0.84-1.76; model 2: RR = 1.39; 95% CI, 0.9-2.15).

In addition, the researchers reported no difference in mortality for patients with COVID-19 with and without asthma. In this cohort, mortality was 3.6% in patients with COVID-19 and asthma and 4.9% in patients with COVID-19 without asthma.

“More studies must be done to look at the underlying immune modulation caused by asthma or asthma treatment to see what impact it may have on COVID-19 outcomes,” Peters said.

Another limitation of the study was that the researchers were unable to assess the contribution of asthma severity or asthma endotypes to COVID-19 disease severity.