3.5 Emergency room visit
Three studies14,18,20 were included in this outcome. Heterogeneity test analysis suggested that there was no heterogeneity (I2=0%, P=0.87). The meta-analysis demonstrated there was significant difference between two groups(OR =0.11, 95%CI= [0.04,0.26], Z=4.98, P<0.00001)(Figure 4), during COVID-19 pandemic, the emergency room visits of asthma were lower than that before COVID-19 pandemic.