Fig. 9

Forest plot: subgroup meta-analysis of the duration of SARS-CoV-2 RNA positivity from the onset of COVID-19 in the upper respiratory tract samples based on the locality. The duration of SARS-CoV-2 RNA positivity from the onset of COVID-19 in the Asian countries (a) and European countries (b) was calculated using the random effects model. The duration of SARS-CoV-2 RNA positivity from the onset of COVID-19 in the Asian countries (c) and European countries (d) from the studies with the mean age of 40 years or older and the proportion of severe patients of 40% or more was calculated using the random effects model. MRAW, the raw data of mean; 95%-CI, 95% confidence interval