Does Asthma Increase the Mortality of Patients with COVID-19?: A Systematic Review and Meta-Analysis

The purpose of this systematic review and meta-analysis was to explore the literature and collate data comparing the mortality of coronavirus disease 2019 (COVID-19) patients with and without asthma. The databases PubMed, Scopus, Embase, Google Scholar, and medRxiv.org were searched for studies comparing the clinical outcomes of asthmatic patients with those of nonasthmatic patients diagnosed with COVID-19. Mortality data were summarized using the Mantel-Haenszel OR with 95% CI in a random-effects model. Five retrospective studies met the inclusion criteria. A meta-analysis of data from 744 asthmatic patients and 8,151 nonasthmatic patients indicated that the presence of asthma had no significant effect on mortality (OR = 0.96; 95% CI 0.70-1.30; I2 = 0%; p = 0.79). Results were stable in a sensitivity analysis. A descriptive analysis of other clinical outcomes indicated no difference in the duration of hospitalization and the risk of intensive care unit (ICU) transfer between asthmatic and nonasthmatic patients. To conclude, preliminary data indicates that asthma as a comorbidity may not increase the mortality of COVID-19. Data on the influence of asthma on the risk of hospitalization, the duration of hospitalization, the requirement of ICU admission, and disease severity is still too limited to draw any strong conclusions. Further studies with a larger sample size are required to establish strong evidence.