Impact of COVID-19 Pandemic on Incidence of Asthma Exacerbations and Hospitalizations in US Specialist-Treated Patients with Severe Asthma: Results from the CHRONICLE Study

RATIONALE: The impact of the COVID-19 pandemic on disease control in patients with severe asthma (SA) has not been described. Anecdotal reports suggest that social distancing, exposure avoidance, and restrictions on travel may have impacted the incidence of asthma exacerbations. Methods: CHRONICLE is an observational study of specialist-treated US adults (aged ≥18 years) with SA. At enrollment, patients must be: (1) receiving FDAapproved monoclonal antibody therapy for SA;(2) receiving systemic corticosteroids (SCS) or other systemic immunosuppressants for ≥50% of the prior 12 months;or (3) persistently uncontrolled while treated with highdosage inhaled corticosteroids and additional controllers. Specialists report all exacerbations and asthma hospitalizations for enrolled patients from 12 months prior to enrollment, with updates provided every 6 months. To describe the effect of the COVID-19 pandemic, we calculated the incidence of these events by month from July 2018 to May 2020 (latest month with complete data) among patients enrolled through November 2020. Results: Among enrolled patients (N=2633), specialist-reported exacerbations and asthma hospitalizations declined significantly in April and May 2020, following varying state/local COVID-19-related stay-at-home orders and social distancing recommendations. Relative to the average rates from July 2018 to March 2020, exacerbations (Figure panel A) and asthma hospitalizations (Figure panel B) were 47% and 57% lower, respectively, in April 2020 and 72% and 74% lower, respectively, in May 2020. Relative to the same months in 2019, exacerbations and asthma hospitalizations were 49% and 58% lower, respectively, in April 2020 and 67% and 74% lower, respectively, in May 2020. Conclusions: There was a notable decline in exacerbations and asthma hospitalizations among US patients with SA coincident with COVID-19-related stay-at-home orders and social distancing recommendations. Reasons for these declines are likely multifactorial and may be explained by reduced viral infections due to reduced social contact, altered patient behavior, and possibly reduced access to care. Rates in later months will be evaluated as data become available.