COVID-19 studies:  C19 studies: C19:  IvermectinIVM Vitamin DV.D HC QHC Q Vitamin CV.C ZincZn PVP-IPVP-I REGNREGN LY-CoVLY RemdesivirRMD
HCQ meta analysis
9/30 PrEP, PEP, Early
Ladapo et al., medRxiv, doi:10.1101/2020.09.30.20204693 (Preprint) (meta analysis - not included in study count)
Randomized Controlled Trials of Early Ambulatory Hydroxychloroquine in the Prevention of COVID-19 Infection, Hospitalization, and Death: Meta-Analysis
Source   PDF   Share   Tweet
Meta analysis of prophylactic and early treatment RCTs, 24% reduction in cases, hospitalization or death with HCQ, RR 0.76, p=0.025. No serious adverse cardiac events were reported. 5,577 patients.
The Boulware study provides a breakdown for treatment delay. For the case of < ~4 days (2 days enrollment, ~46 hours shipping), the result of the meta analysis becomes RR 0.68, p=0.0097.
The actual effect may be larger due to treatment delays, followup loss, protocol deviation, active placebos, no severity analysis for cases, and suboptimal regimens.
For the individual studies see [1, 2, 3, 4, 5].

Ladapo et al., 9/30/2020, preprint, 4 authors.
risk of combined cases/death/hospitalization, 24.0% lower, RR 0.76, p = 0.03.
Details of all 230 studies    Meta analysis
Please submit corrections, updates, or comments.