It is unclear if there is the influence of asthma on contracting COVID-19, or having worse outcomes from COVID-19 disease.
To explore the prevalence of asthma in COVID-19 patients and the relationship between asthma and COVID-19 patients with poor outcomes.
The pooled prevalence of asthma in COVID-19 patients and corresponding 95% confidence interval (CI) were estimated. The pooled effect size (ES) was used to evaluate the association between asthma and COVID-19 patients with poor outcomes.
The pooled prevalence of asthma in COVID-19 patients worldwide was 8.3% (95% CI 7.6-9.0%) based on 116 articles (119 studies) with 403,392 cases. The pooled ES based on unadjusted effect estimates showed that asthma was not associated with the reduced risk of poor outcomes in COVID-19 patients (ES 0.91, 95% CI 0.78-1.06). Similarly, the pooled ES based on unadjusted effect estimates revealed that asthma was not associated with the reduced risk of mortality in COVID19 patients (ES 0.88, 95% CI 0.73-1.05). However, the pooled ES based on adjusted effect estimates indicated that asthma was significantly associated with the reduced risk of mortality in COVID-19 patients (ES 0.80, 95% CI 0.74-0.86).
The pooled prevalence of asthma in COVID-19 patients was similar to that in the general population, and asthma might be an independent protective factor for the death of COVID-19 patients, which suggests that we should pay high attention to COVID-19 patients with asthma and take locally tailored interventions and treatment. Further well-designed studies with large sample sizes are required to verify our findings.