Study		Exclusion reasons	Remarks	Reference(s)
Rimland, 2020	single-arm
BREATH-19 Study, 0	single-arm
Holt, 2020	retrospective cohort	other	no CI reported	Holt, Gregory E 10.21203/rs.3.rs-39875/v1
Klopfenstein, 2020	retrospective cohort	other	major flaws in the method	Klopfenstein T International Journal of Infectious Diseases 10.1016/j.ijid.2020.08.024