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
, 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).
This study is excluded in the after exclusion results of meta
not fully adjusting for the different baseline risk of systemic autoimmune patients.
de la Iglesia et al., 2 Sep 2020, retrospective, database analysis, Spain, preprint, 17 authors.