Asthma in a large COVID-19 cohort: Prevalence, features, and determinants of COVID-19 disease severity

Background: Asthma prevalence among COVID-19 patients seems to be surprisingly low. However the clinical profile of COVID-19 asthmatic patients and potential determinants of higher susceptibility/worse outcome have been scarcely investigated. We aimed to describe the prevalence and features of asthmatic patients hospitalized for COVID-19 and to explore the association between their clinical asthma profile and COVID-19 severity.

Methods: Medical records of patients admitted to COVID-Units of six Italian cities major hospitals were reviewed. Demographic and clinical data were analyzed and compared according to the COVID-19 outcome (death/need for ventilation vs discharge at home without requiring invasive procedures).

Results: Within the COVID-Units population (n = 2000) asthma prevalence was 2.1%. Among the asthmatics the mean age was 61.1 years and 60% were females. Around half of patients were atopic, blood eosinophilia was normal in most of patients. An asthma exacerbation in the 6 months before the Covid-Unit admittance was reported by 18% of patients. 24% suffered from GINA step 4-5 asthma, and 5% were under biologic treatment. 31% of patients were not on regular treatment and a negligible use of oral steroid was recorded. Within the worse outcome group, a prevalence of males was detected (64 vs 29%, p = 0.026); they suffered from more severe asthma (43 vs 14%, p = 0.040) and were more frequently current or former smokers (62 vs 25%, p = 0.038).

Conclusions: Our report, the first including a large COVID-19 hospitalized Italian population, confirms the low prevalence of asthma. On the other side patients with GINA 4/5 asthma, and those not adequately treated, should be considered at higher risk.