Study Exclusion reasons Remarks Reference(s)
BCN PEP-CoV-2-Study 2 (Mitja Lancet-preprint), 2020 randomized controlled trial

Mitja O et al. Lancet preprint

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

Raquel, 2019 randomized controlled trial other reason

Raquel Benedita Terrabuio Hepatol Commun 2019; 3:116-128 10.1002/hep4.1275

ChiCTR2000029975, 0 single-arm not relevant study design  
Jacobson, 2016 randomized controlled trial not relevant study design

Jacobson AIDS Res. Hum. Retroviruses 2016; 32:636-47 10.1089/AID.2015.0336

Sperber, 1995 randomized controlled trial not relevant outcome

Sperber Clin Ther ; 17:622-36 10.1016/0149-2918(95)80039-5

Paton, 2012 randomized controlled trial not relevant outcome

Paton JAMA 2012; 308:353-61 10.1001/jama.2012.6936

ChiCTR2000029826 (Cancelled by the investigator), 0 randomized controlled trial cancelled by investigator  
Duke university (Hydroxychloroquine), 2020 randomized controlled trial cancelled by investigator  
Million, 2020 single-arm no control group

Million Travel Med Infect Dis 2020; :101738 10.1016/j.tmaid.2020.101738

Mohana, 2020 retrospective cohort (claims database) no control group

Mohana A Int J Infect Dis 2020 Oct 16;S1201-9712(20)32235-9. 10.1016/j.ijid.2020.10.031

Thakar, 2021 randomized controlled trial no clinically relevant endpoint

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

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

Guerin, 2020 non randomized controlled trial other no binary endpoints

Guérin, Preprints 2020, 2020050486 (doi: 10.20944/preprints202005.0486.v1).

Kanran M, 2020 randomized controlled trial other randomization process unclear : Thepatients who did not give consent for treatment with HCQ or had a known allergy to HCQ orchloroquine or had another known contraindication to treatment with the study drug, includingretinopathy, G6PD deficiency and QT prolongation served as controls

sultan mehmood kamran medRxiv 10.1101/2020.07.30.20165365

Alberici, 2020 retrospective cohort other HCQ efficacy or safety evaluation wasn't a prespecified endpoint

Alberici F Kidney Int 2020 Jul;98(1):20-26. 10.1016/j.kint.2020.04.030

Thakar, 2021 randomized controlled trial other chloroquine nasal drops

Thakar A Indian J Med Res 2021 Jan & Feb;153(1 & 2):151-158. 10.4103/ijmr.IJMR_3665_20