Background: There is uncertainty about the effect of inhaled corticosteroids (ICS) in COVID-19.

Aim: To determine if pre-hospital use of ICS has a protective effect on outcomes of hospitalized COVID-19 patients.

Methods: A prospective, international, observational cohort study using data from the Society of Critical Care Medicine Discovery Viral Respiratory Illness Universal Study (VIRUS) COVID-19 registry, from February 2020 through October 2021. Patients were divided into four groups: asthma, other chronic pulmonary diseases (CPD), asthma and CPD and no underlying respiratory disease. Primary outcome was hospital mortality and secondary outcome was invasive mechanical ventilation (IMV).

Results: From 17 625 patients with available pre-hospital medications, 417/1 254 with asthma (33%), 438/1 394 (31%) with CPD, 106/280 (38%) with asthma and CPD, and 536/14 697 (4%) of patients without underlying respiratory disease received ICS. After adjusting for age, sex, race, ethnicity and Elixhauser comorbidity index the use of ICS was not associated with hospital mortality in asthma (aOR 1.18, 95%CI 0.83-1.69), CPD (aOR 1.06, 95%CI 0.83-1.36), asthma and CPD (aOR 1.54, 95%CI 0.78-3.04), and patients without underlying respiratory disease (aOR 0.96, 95%CI 0.77-1.21). Need for IMV was reduced in patients without underlying respiratory disease (aOR 0.71, 95%CI 0.57-0.88), but not in patients with asthma (aOR 1.27, 95%CI 0.96-1.67), CPD (aOR 1.00, 95%CI 0.78-1.28), and asthma and CPD (aOR 1.41,95%CI 0.75-2.65).

Conclusions: The use of pre-hospital ICS was not associated with COVID -19 hospital mortality. Pre-hospital use of ICS was associated with reduced IMV risk in patients without underlying respiratory disease.