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
Ivermectin OR 0.27, p
Vitamin C OR 0.82, p
Behera et al., 11/3/2020, retrospective, India, South Asia, peer-reviewed, 13 authors.
risk of COVID-19 case, 9.6% lower, RR 0.90, p = 0.58, treatment 29 of 67 (43.3%), control 157 of 305 (51.5%), adjusted per study, odds ratio converted to relative risk, model 2 conditional logistic regression.
risk of COVID-19 case, 16.5% lower, RR 0.83, p = 0.04, treatment 29 of 67 (43.3%), control 157 of 305 (51.5%), adjusted per study, 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.