Retrospective matched case-control prophylaxis study for HCQ, ivermectin, and vitamin C with 372 healthcare workers, showing lower COVID-19 incidence for all treatments, with statistical significance reached for ivermectin.
HCQ OR 0.56,
p = 0.29
Ivermectin OR 0.27,
p < 0.001
Vitamin C OR 0.82,
p = 0.58
Behera et al., 11/3/2020, retrospective, India, South Asia, peer-reviewed, 13 authors.
risk of COVID-19 case, 27.9% lower, RR 0.72, p = 0.29, treatment 7 of 19 (36.8%), control 179 of 353 (50.7%), adjusted per study, odds ratio converted to relative risk, model 2 conditional logistic regression.
risk of COVID-19 case, 26.3% lower, RR 0.74, p = 0.25, treatment 7 of 19 (36.8%), control 179 of 353 (50.7%), odds ratio converted to relative risk, matched pair analysis.
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.