et al., Med (2020), doi:10.1016/j.medj.2020.06.001 (preprint 4/21) (Peer Reviewed)
Retrospective 807 hospitalized patients, no statistically significant reduction in mortality or the need for mechanical ventilation with HCQ or HCQ+AZ, or for death with HCQ+AZ, HR 1.83, p
=0.009 for HCQ mortality.
The preprint notes that HCQ was more likely to be prescribed to patients with more severe disease, however this was deleted in the published version.
425 patients had dispositions of death or discharge by the end of the study period and thus did not encounter the issue of length-biased sampling and differential rates of right-censored observations among the groups.
Also see: 
Magagnoli et al., 4/21/2020, retrospective, database analysis, USA, North America, peer-reviewed, 7 authors.
risk of death, 11.0% lower, RR 0.89, p = 0.74, treatment 39 of 148 (26.4%), control 18 of 163 (11.0%), adjusted per study, HCQ+AZ w/dispositions.
risk of death, 1.0% lower, RR 0.99, p = 0.98, treatment 30 of 114 (26.3%), control 18 of 163 (11.0%), adjusted per study, HCQ w/dispositions.
risk of death, 31.0% higher, RR 1.31, p = 0.28, treatment 49 of 214 (22.9%), control 37 of 395 (9.4%), adjusted per study, HCQ+AZ.
risk of death, 83.0% higher, RR 1.83, p = 0.009, treatment 38 of 198 (19.2%), control 37 of 395 (9.4%), adjusted per study, HCQ.
Effect extraction follows pre-specified rules
prioritizing more serious outcomes. For an individual study the most serious
outcome may have a smaller number of events and lower statistical signficance,
however this provides the strongest evidence for the most serious outcomes
when combining the results of many trials.