Very small retrospective study of rheumatic disease patients, sample size is too small for statistical significance (HCQ 0.5-4.0%, no-HCQ 0.4-2.7%). Confirmed cases were 1 HCQ and 2 no-HCQ, confirmed+likely cases were 1 HCQ and 3 no-HCQ. 1 HCQ and 2 no-HCQ patients were admitted to hospital. We do not think a conclusion can be drawn based on these sample sizes.
There are very significant differences between the groups, for example 30% of the HCQ group have SLE vs. 2.5% of the no-HCQ group. SLE patients have a 5.7 times relative risk of pneumonia according to [ncbi.nlm.nih.gov]
, whereas the relative risk with glucocorticoids and TNF-α inhibitors is significantly lower [academic.oup.com]
. Two more recent studies with rheumatic disease/autoimmune condition patients provide higher confidence.
Although the 26% lower hospitalization is not statistically significant, it is consistent with the significant 17% lower hospitalization [7‑26%]
from meta analysis of the 55 hospitalization results to date
This study is excluded in the after exclusion results of meta
not fully adjusting for the baseline risk differences within systemic autoimmune patients.
Macias et al., 16 May 2020, retrospective, database analysis, Spain, preprint, 12 authors.