J Asthma. 2021 Feb 8:1-22. doi: 10.1080/02770903.2021.1888116. Online ahead of print.
Objective As COVID-19 spreads across the world, there are concerns that people with asthma are at a higher risk of acquiring the disease, or of poorer outcomes. This systematic review aimed to summarise evidence on the risk of infection, severe illness and death from COVID-19 in people with asthma. Data Sources and Study Selection A comprehensive search of electronic databases including preprint repositories and WHO COVID-19 database was conducted (until 26 May 2020). Studies reporting COVID-19 in people with asthma were included. For binary outcomes, we performed Sidik-Jonkman random effects meta-analysis. We explored quantitative heterogeneity by subgroup analyses, meta regression and evaluating the I2 statistic. Results Fifty-seven studies with an overall sample size of 587,280 were included. The prevalence of asthma among those infected with COVID-19 was 7.46% (95% CI =6.25-8.67). Non-severe asthma was more common than severe asthma (9.61% vs. 4.13%). Pooled analysis showed a 14% risk ratio reduction in acquiring COVID-19 (95% CI =0.80-0.94; p < 0.0001) and 13% reduction in hospitalisation with COVID-19 (95% CI =0.77-0.99, p = 0.03) for people with asthma compared with those without. There was no significant difference in the combined risk of requiring admission to ICU and/or receiving mechanical ventilation for people with asthma (RR =0.87 95% CI =0.94-1.37; p = 0.19) and risk of death from COVID-19 (RR =0.87; 95% CI =0.68-1.10; p = 0.25). Conclusion The findings from this study suggest that the prevalence of people with asthma among COVID-19 patients is similar to the global prevalence of asthma. The overall findings suggest that people with asthma have a lower risk than those without asthma for acquiring COVID-19 and have similar clinical outcomes.