Meta-Analysis Finds Reduced COVID-19 Mortality Risk in Patients With Asthma

Asthma is significantly associated with a reduced risk for COVID-19 mortality, suggests an updated meta-analysis published in The Journal of Allergy and Clinical Immunology: In Practice.

“This meta-analysis on the basis of adjusted effects estimates found that COVID-19 patients with asthma had a significantly reduced risk for mortality compared with those without asthma, which suggests that asthma might be an independent protective factor for developing fatal outcomes among COVID-19 patients,” wrote a research team from Zhengzhou, China.

The meta-analysis included 62 studies from North America, Europe, Asia, and other regions spanning nearly 2.5 million patients with COVID-19. All studies reported adjusted effect estimates, which considered the influence of age, sex, and other confounding factors.

Analysis of 15 cohort studies that included 829,670 patients revealed a pooled hazard ratio of 0.88 of COVID-19 mortality in patients with asthma, researchers reported. Pooled odds ratios of COVID-19 fatality with asthma were 0.88 in an analysis of 34 cohort studies involving 1 million patients and 0.87 in an analysis of 11 cross-sectional studies involving 1.1 million patients.

Subgroup analyses based on types of adjusted factors showed patients with asthma had a significantly reduced risk for COVID-19 mortality in studies adjusting for demographic, clinical, and epidemiologic variables, according to the report, but not studies adjusting for demographic variables alone.

“Although the detailed mechanisms underlying the association between asthma and the reduced risk for COVID-19 mortality are unclear, several possibilities exist: (1) COVID-19 patients with asthma may receive more medical care in clinical practice; (2) the use of inhaled corticosteroids, allergen immunotherapy, and biological agents might be beneficial through suppressing viral replication and alleviating inflammation; and (3) type 2 immune response in patients with asthma might counteract the severe acute respiratory syndrome coronavirus 2 infection-induced inflammatory process,” researchers wrote.

In light of meta-analysis results, investigators advised the continuation of routine interventions and treatment for patients with asthma infected with SARS-CoV-2.

Reference:
Hou H, Xu J, Li Y, Wang Y, Yang H. The association of asthma with COVID-19 mortality: an updated meta-analysis based on adjusted effect estimates. J Allergy Clin Immunol Pract. 2021;9(11):3944-3968.e5. doi:10.1016/j.jaip.2021.08.016