RCT 1,360 healthcare workers in the USA showing OR 0.75 [0.49-1.15] for confirmed or suspected COVID-19 clinical infection by day 30. There were no significant safety issues. Authors note that pooling the results with the COVID PREP study gives OR 0.74 [0.55-1.0] p
= 0.046. NCT04334148
Naggie et al., 8/25/2021, Randomized Controlled Trial, USA, North America, preprint, 22 authors.
risk of symptomatic case, 23.5% lower, RR 0.76, p = 0.18, treatment 41 of 683 (6.0%), control 53 of 676 (7.8%), odds ratio converted to relative risk, logistic regression.
risk of symptomatic case, 29.3% lower, RR 0.71, p = 0.18, treatment 41 of 683 (6.0%), control 53 of 676 (7.8%), odds ratio converted to relative risk, Mantel–Haenszel.
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.