The Association of Asthma With COVID-19 Mortality: An Updated Meta-Analysis Based on Adjusted Effect Estimates.

Abstract

The association of asthma with the risk for mortality among coronavirus disease 2019 (COVID-19) patients is not clear. To investigate the association between asthma and the risk for mortality among COVID-19 patients. We performed systematic searches through electronic databases including PubMed, EMBASE, and Web of Science to identify potential articles reporting adjusted effect estimates on the association of asthma with fatal COVID-19. A random-effects model was conducted to estimate pooled effects. Sensitivity analysis, subgroup analysis, meta-regression, Begg's test and Egger's test were also performed. Based on 62 studies with 2,457,205 cases reporting adjusted effect estimates, COVID-19 patients with asthma had a significantly reduced risk for mortality compared with those without it (15 cohort studies: 829,670 patients, pooled hazard ratio [HR] = 0.88, 95% confidence interval [CI], 0.82-0.95, I² = 65.9%, P < .001; 34 cohort studies: 1,008,015 patients, pooled odds ratio [OR] = 0.88, 95% CI, 0.82-0.94, I² = 39.4%, P = .011; and 11 cross-sectional studies: 1,134,738 patients, pooled OR = 0.87, 95% CI, 0.78-0.97, I² = 41.1%, P = .075). Subgroup analysis based on types of adjusted factors indicated that COVID-19 patients with asthma had a significantly reduced risk for mortality among studies adjusting for demographic, clinical, and epidemiologic variables (pooled OR = 0.87, 95% CI, 0.83-0.92, I² = 36.3%, P = .013; pooled HR = 0.90, 95% CI, 0.83-0.97, I² = 69.2%, P < .001), but not among studies adjusting only for demographic variables (pooled OR = 0.88, 95% CI, 0.70-1.12, I² = 40.5%, P = .097; pooled HR = 0.82, 95% CI, 0.64-1.06, I² = 0%, P = .495). Sensitivity analysis proved that our results were stable and robust. Both Begg's test and Egger's test indicated that potential publication bias did not exist. Our data based on adjusted effect estimates indicated that asthma was significantly related to a reduced risk for COVID-19 mortality.