Prodromos et al., New Microbes and New Infections, doi:10.1016/j.nmni.2020.100776 (Peer Reviewed) (meta analysis - not included in study count) Hydroxychloroquine is effective, and consistently so used early, for Covid-19: A systematic review
Meta analysis of 43 studies: "HCQ was found consistently effective against COVID-19 when used early, in the outpatient setting. It was found overall effective also including inpatient studies. No unbiased study found worse outcomes with HCQ use. No mortality or serious safety adverse event was found.
Prodromos et al., 10/5/2020, peer-reviewed, 2 authors.