Retrospective 67 hospitalized patients in the USA showing non-statistically significant unadjusted increased mortality with HCQ. Confounding by indication is likely.
Time varying confounding is likely. HCQ became controversial and was suspended during the end of the period studied, therefore HCQ use was likely more frequent toward the beginning of the study period, a time when overall treatment protocols were significantly worse.
Psevdos et al., 12/31/2020, retrospective, USA, North America, peer-reviewed, 3 authors.
risk of death, 63.5% higher, RR 1.63, p = 0.52, treatment 17 of 52 (32.7%), control 3 of 15 (20.0%).
This study is excluded in the after exclusion results of meta analysis: unadjusted results with no group details, no treatment details, substantial time varying confounding likely due to declining usage over the early period when overall treatment protocols improved dramatically, substantial unadjusted confounding by indication likely.
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.