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
risk of disease progression, 1.0% higher, RR 1.01, p = 0.11, treatment 104 of 272 (38.2%), control 774 of 2,533 (30.6%), adjusted per study, multivariate.
risk of case, 4.0% lower, RR 0.96, p = 0.82, treatment 329 of 1,874 (17.6%), control 7,012 of 42,172 (16.6%), adjusted per study, multivariate.
Huh et al., 12/19/2020, retrospective, database analysis, South Korea, Asia, peer-reviewed, 8 authors.
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 significance,
however this provides the strongest evidence for the most serious outcomes
when combining the results of many trials.