Study Exclusion reasons Remarks Reference(s)
HYDRA, 2020 randomized controlled trial Initially found in Axfors et al. meta-analysis results published by Hernadez et al  
CloroCOVID19, 2020 randomized controlled trial inadequate or absent control group This paper reports partial results from an unplanned interim analysis.Efficacy and safety criteria do not appear to have ever been assessed on the same number of patients (denominators are different for almost every criterion and are less than the number of patients randomized). Compared to the registration record, the patient eligibility criteria were changed.

Borba JAMA Netw Open 2020; 3:e208857 10.1001/jamanetworkopen.2020.8857

Mayla Borba for CloroCovid-19 Team medRxiv 2020.04.07.20056424

 
Ye et al., 2020 observational study not relevant study design

Ye Eur Rev Med Pharmacol Sci 2020; 24:3390-3396 10.26355/eurrev_202003_20706

 
ChiCTR2000029975, 0 single-arm not relevant study design  
Duke university (Hydroxychloroquine), 2020 randomized controlled trial cancelled by investigator  
Duke University azithromycin, 2020 randomized controlled trial cancelled by investigator Discontinuated : Poor recruitment, strong evidence from larger trials of no therapeutic benefit  
ChiCTR2000029826 (Cancelled by the investigator), 0 randomized controlled trial cancelled by investigator  
SIMPLE (Grein), 0 single-arm no control group single-arm with external control group

Grein N. Engl. J. Med. 2020; 382:2327-2336 10.1056/NEJMoa2007016

 
Erdem, 2020 retrospective cohort (registry) no control group

Erdem HA Turk J Med Sci 2020 Nov 25. 10.3906/sag-2008-33

 
Hazan, 2021 case series no control group

Hazan S et al. medrxiv;2021.07.06.21259924v1 10.1101/2021.07.06.21259924

 
Yamamura, 2020 single-arm no control group

Yamamura H Crit Care 2020 Jul 9;24(1):413. 10.1186/s13054-020-03137-5

 
Hazan, 2021 case series no control group

Hazan S et al. medrxiv;2021.07.06.21259924v1 10.1101/2021.07.06.21259924

 
Murohashi, 2020 prospective cohort no control group

Murohashi K Respir Investig 2020 Aug 28;58(6):430-434. 10.1016/j.resinv.2020.08.001

 
Nasir, 2020 non randomized controlled trial no clinically relevant endpoint

Nasir A et al. 10.2139/ssrn.3734478

 
Thakar, 2021 randomized controlled trial no clinically relevant endpoint

Thakar A Indian J Med Res 2021 Jan 21. 10.4103/ijmr.IJMR_3665_20

 
Dabbous, 2021 randomized controlled trial other Withdrawal of the publication.

Dabbous HM Arch Virol 2021 Jan 25;1-6. 10.1007/s00705-021-04956-9

 
IFORS (Pott-Junior), 2020 randomized controlled trial other The article has been retracted by Toxicology Reports

Pott-Junior H Toxicol Rep 2021;8:505-510. 10.1016/j.toxrep.2021.03.003

 
Elgazzar - treatment, 2020 randomized controlled trial other withdrawal of the publication

Elgazzar A et al. 10.21203/rs.3.rs-100956/v2

 
Barbosa, 2020 retrospective cohort other the only document variable for this study is a copy of a submission to NEJM. It is impossible to verify the veracity of this document. The paper was submitted apr 4th and since this date ther is no publication in NEJM or in other media (included preprint server).  
Mallat, 2020 retrospective cohort other inapropriate statistical analysis. Time to events analyszed with means without taken into account the censure due to death or lost to follow-up

Jihad Mallat, Fadi Hamed, Maher Balkis, Mohamed A Mohamed, Mohamad Mooty, Asim Malik, Ahmad Nusair, Fernanda Bonilla medRxiv 2020.04.27.20082180 10.1101/2020.04.27.20082180

 
Mehra, 2020 retrospective cohort other the paper was retracted by 3 authors on June 4, 2020

Mehra MR Lancet 2020 May 22;S0140-6736(20)31180-6. 10.1016/S0140-6736(20)31180-6

Mehra MR Lancet 2020 Jun 13;395(10240):1820. 10.1016/S0140-6736(20)31324-6

 
Niaee (vs placebo), 2020 randomized controlled trial other On 8 October 2021 and 9 October 2021, two articles were published by subject-matter experts outlining concerns about various aspects of the study and, in particular, calling into question the randomization of participants. The authors and publishing journal have been alerted to these issues, and this note will be updated with any new information related to the publication.

Niaee MS et al. researchsquare 10.21203/rs.3.rs-109670/v1

Niaee MS et al. Asian Pacific Journal of Tropical Medicine 10.4103/1995-7645.318304

 
Mehra, 2020 retrospective cohort other the paper was retracted by 3 authors on June 4, 2020

Mehra MR Lancet 2020 May 22;S0140-6736(20)31180-6. 10.1016/S0140-6736(20)31180-6

Mehra MR Lancet 2020 Jun 13;395(10240):1820. 10.1016/S0140-6736(20)31324-6

 
Cadegiani -Iver, 2020 observational study other unappropriated control group

Cadegiani FA medrxiv https://doi.org/10.1101/2020.10.31.20223883