Analysis of autoimmune disease patients on HCQ, compared to a control group from the general population (matched on age and sex, but not adjusted for autoimmune disease), showing non-significant differences between groups.
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
<0.001 , which is the observed real-world risk, taking into account factors such as these patients potentially being more careful to avoid exposure.
If we adjust for the different baseline risk, the mortality result becomes RR 0.35, p
=0.23, suggesting a substantial benefit for HCQ treatment (as shown in other studies).
de la Iglesia et al., 9/2/2020, retrospective, database analysis, Spain, Europe, preprint, 17 authors.
risk of hospitalization, 50.0% higher, RR 1.50, p = 1.00, treatment 3 of 687 (0.4%), control 2 of 688 (0.3%).
risk of COVID-19 case, 42.6% higher, RR 1.43, p = 0.15, treatment 42 of 648 (6.5%), control 30 of 660 (4.5%), suspected COVID-19.
risk of COVID-19 case, 7.8% lower, RR 0.92, p = 0.84, treatment 12 of 678 (1.8%), control 13 of 677 (1.9%), confirmed COVID-19.
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.