Retrospective database study of 5683 patients, 692 received HCQ/CQ+AZ, 200 received HCQ/CQ, 203 received ivermectin, 1600 received AZ, 358 received ivermectin+AZ, and 2630 received standard of care.
This study includes anyone with ICD-10 COVID-19 codes which includes asymptomatic PCR+ patients, therefore many patients in the control group are likely asymptomatic with regards to SARS-CoV-2, but in the hospital for another reason. For those that had symptomatic COVID-19, there is also likely significant confounding by indication.
In this study all medications show higher mortality at day 30, which is consistent with asymptomatic (for COVID-19) or mild condition patients being more common in the control group.
For HCQ they show 30 day mortality aHR = 1.84 [1.12 - 3.02]. KM curves show that the treatment groups were in more serious condition, and that after about 37 days survival became better with HCQ. More than the total excess mortality happened on the first day. This is consistent with treated patients being in more serious condition, and with many of the control group patients being in hospital for something unrelated to COVID-19.
Authors use a machine learning based propensity scoring system that appears over-parameterized and likely to result in significant overfitting and inaccurate results. Essentially they test for all interactions between two and three covariates. The nature and large number of covariates means many random correlations may be found. COVID-19 severity is not used.
See also: .
Soto-Becerra et al., 10/8/2020, retrospective, database analysis, Peru, South America, preprint, median age 59.4, 4 authors.
risk of death, 18.1% lower, RR 0.82, p < 0.001, treatment 346 of 692 (50.0%), control 1606 of 2630 (61.1%), day 54 (last day available) weighted KM.
risk of death, 84.0% higher, RR 1.84, p = 0.02, treatment 165 of 692 (23.8%), control 401 of 2630 (15.2%), adjusted per study, day 30.