Study Exclusion reasons Remarks Reference(s)
BREATH-19 Study, 0 single-arm  
Gritti et al., 2020 single-arm inadequate or absent control group

Gritti et al. medRxiv 10.1101/2020.04.01.20048561

 
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