Impact of treatment with inhaled corticosteroids on COVID-19 risk and outcome – a potential protective effect on severity of disease and survival

Background: Inhaled corticosteroid therapy (ICS) is an important therapeutic modality in chronic respiratory diseases, and patients with chronic obstructive pulmonary disease (COPD) are severely affected by COVID-19. The role of ICS in COVID-19 has been studied, however, ambiguities remain, especially for COPD patients. Aim: To investigate whether ongoing regular exposure to ICS affects risk, severity or survival in SARS-CoV-2 infection, using a large linked Swedish population register database. Methods: From January to December 2020, we studied in two study populations (general population and COPD patients) three different study cohorts: 1. the whole group, 2. COVID-19-diagnosed individuals, and 3. hospitalized COVID-19 patients. Ongoing regular exposure to ICS was defined as ≥1 ICS prescriptions during the year before the index date. Studied outcomes were: COVID-19 diagnosis, hospitalization, intensive care and death. Results: After matching, in the general population ICS therapy was not associated with an increased onset or COVID-19, hospitalization, ICU admission or fatal outcomes, both in the general cohort and COPD patients group. Similarly, in patients who acquired COVID-19, ICS therapy was not associated with hospitalization, ICU admission or death in both groups. A slight increase for ICU admission was observed in the hospitalized general patients cohort who received ICS therapy (H.R. 1.22 [1.05, 1.42]), however, COPD patients did not have an increased risk for adverse outcomes. Conclusion: Patients receiving ICS therapy did not have an increased risk for acquiring Covid 19, hospitalization, ICU admission or fatal outcomes.