et al., Turk. J. Haematol.,
Retrospective 340 patients with hematological malignancy in Turkey, showing higher mortality with HCQ treatment. Confounding by time is likely because more HCQ patients were earlier in time when overall treatment protocols were significantly worse.
Çivriz Bozdağ et al., 9/15/2021, retrospective, Turkey, Europe, peer-reviewed, 62 authors.
risk of death, 399.2% higher, RR 4.99, p = 0.003, treatment 35, control 140.
This study is excluded in the after exclusion results of meta analysis: substantial time varying confounding likely due to declining usage over the early period when overall treatment protocols improved dramatically.
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.