Flowchart

Last update : 2020-09-04

Electronic databases
(n=49616, from PubMed)
Archives and curated websites
(n = 7426 from MedRxiv, ChinaXiv)
Other sources
(n = 61)

Records after duplicates removed
(n=38325)



Records screened
(n = 45812)


Records excluded
(n = 45100)

Full-text articles assessed for eligibility
(n = 712)


Full-text articles excluded:
(n = 383)

Randomized Controlled Trials
(n=63)