et al., Turk. Thorac. J.,
Retrospective 202 patients in Saudi Arabia not showing significant differences with treatment. No information is provided on how patients were selected for treatment, there may be significant confounding by indication. Time varying confounding is also likely as HCQ became controversial during the period studied, therefore HCQ use was likely more frequent toward the beginning of the period, a time when overall treatment protocols were significantly worse.
Lotfy et al., 1/1/2021, retrospective, Saudi Arabia, Middle East, peer-reviewed, mean age 55.0, 3 authors.
risk of death, 24.8% higher, RR 1.25, p = 0.76, treatment 6 of 99 (6.1%), control 5 of 103 (4.9%).
risk of mechanical ventilation, 41.2% higher, RR 1.41, p = 0.34, treatment 19 of 99 (19.2%), control 14 of 103 (13.6%).
risk of ICU admission, 16.5% higher, RR 1.17, p = 0.53, treatment 28 of 99 (28.3%), control 25 of 103 (24.3%).
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, 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.