Retrospective database analysis with 17 existing users of HCQ and 5 severe cases, showing no significant difference for cases and higher risk for severe cases. However, HCQ users are likely systemic autoimmune disease patients and authors do not adjust for the very different baseline risk for these patients. Other research shows that the risk of COVID-19 for systemic autoimmune disease patients is much higher overall, Ferri et al. show OR 4.42, p
Huh et al., 12/19/2020, retrospective, database analysis, South Korea, Asia, peer-reviewed, 8 authors.
risk of disease progression, 251.0% higher, RR 3.51, p = 0.11, treatment 5 of 8 (62.5%), control 873 of 2,797 (31.2%), adjusted per study.
risk of COVID-19 case, 6.0% lower, RR 0.94, p = 0.82, treatment 17 of 122 (13.9%), control 7,324 of 36,600 (20.0%), adjusted per study.
This study is excluded in the after exclusion results of meta analysis: not fully adjusting for the different baseline risk of systemic autoimmune patients.
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.