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

Abstract

Purpose Patients with severe asthma (SA) are at an increased risk of asthma-related hospitalizations and exacerbations. Despite concerns that COVID-19 circulation would increase exacerbations of SA, anecdotal reports suggest that social distancing and exposure avoidance may have led to reduced exacerbations. Patients and methods CHRONICLE is an ongoing noninterventional observational study of 3100 subspecialist-treated patients with SA. Eligible adults (≥ 18 years of age) have (1) current use of monoclonal antibody (ie, biologic) therapy for SA, (2) use of maintenance systemic corticosteroids (mSCS) or other systemic immunosuppressants for ≥ 50% of the prior 12 months for SA, or (3) persistently uncontrolled asthma while treated with high-dosage inhaled corticosteroids with additional controllers. For enrolled patients, electronic medical records were reviewed to record all exacerbations and asthma-related hospitalizations. Descriptive analyses were conducted of the monthly incidence of exacerbations, exacerbation-related visits to the emergency department (ED), and asthma hospitalizations from July 2018 through July 2021. Results Exacerbations, exacerbation-related ED visits, and hospitalizations decreased since April 2020. Exacerbations in 2020 were 20% to 52% lower in April through August relative to the same months in 2019. Exacerbations remained lower than the prior year through May 2021. Similar results were observed by United States (US) census region, with an earlier decrease in exacerbation rates in the western US versus other regions. Across all months, exacerbation rates were lower among biologic recipients. Conclusion In a clinical cohort of subspecialist-treated patients with SA, there was a meaningful reduction in exacerbations, exacerbation-related ED visits, and asthma hospitalizations following COVID-19–related stay-at-home orders and social distancing recommendations. Reasons for these reductions are likely multifactorial, including reduced viral infections due to less social contact and altered patient behavior.

Incidence of community-acquired pneumonia hospitalisation in persons with bronchiectasis during the COVID-19 lockdown in Denmark: a retrospective cohort study

“… 30 The CHRONICLE Study investigated 3100 patients with severe asthma and found a decrease of 20%–54% in exacerbation rates through five consecutive months in 2020 compared with 2019. 31 This is in line with a Danish study in patients with asthma reporting a decline in the trend for weekly exacerbation rates of −0.75 (hospital-requiring exacerbations) and −12.2 (all exacerbations) during 10 weeks of lockdown. 18 Thus, it seems realistic that our findings are not solely due to random fluctuations in infection rates and that pandemic lockdown measures are effective in reducing exacerbation rates in chronic respiratory diseases of different kinds.…”

“…This tendency is further confirmed by an American study of 123 individuals comparing year 2020 to the three prior years with an average decrease in exacerbation rate of 54% (74% in frequent exacerbators) 30. The CHRONICLE Study investigated 3100 patients with severe asthma and found a decrease of 20%–54% in exacerbation rates through five consecutive months in 2020 compared with 2019 31. This is in line with a Danish study in patients with asthma reporting a decline in the trend for weekly exacerbation rates of −0.75 (hospital-requiring exacerbations) and −12.2 (all exacerbations) during 10 weeks of lockdown 18.…”

Trends in outpatient and inpatient visits for separate ambulatory-care-sensitive conditions during the first year of the COVID-19 pandemic: a province-based study

“…In support of the latter, we demonstrated the most pronounced reductions in inpatient visits for COPD and asthma as a possible unintended benefit. In addition, an increase in adherence to medications for asthma and COPD was also noted this time (51)(52)(53). Fifth, low rates of outpatient visits may not have resulted in more ED visits and hospitalizations because virtual care was able to effectively replace in-person visits (1,45,54).…”

Analyzing COVID-19 and Air Pollution Effects on Pediatric Asthma Emergency Room Visits in Taiwan

“…A reduction in respiratory pathogens is considered the most important factor in reducing asthma exacerbation. The reasons for the reduction in adult asthma exacerbations are multifactorial, with fewer viral infections resulting from fewer social contacts and the use of monoclonal antibodies in the United States [ 28 ]. A decrease in retroviral infection rates has been observed in the United States, and the reduction in infections has the potential to decrease asthma exacerbations [ 29 ].…”