Prophylaxis study with 12,089 Indian healthcare workers, showing lower risk of COVID-19 cases with treatment, and increasingly lower risk for longer durations of HCQ prophylaxis. The appendices are not currently available.
Badyal et al., 6/7/2021, prospective, India, South Asia, peer-reviewed, 18 authors.
risk of COVID-19 case, 60.1% lower, RR 0.40, p < 0.001, treatment 247 of 617 (40.0%), control 611 of 1473 (41.5%), adjusted per study, odds ratio converted to relative risk, >=6 weeks, logistic regression.
risk of COVID-19 case, 35.1% lower, RR 0.65, p < 0.001, treatment 88 of 185 (47.6%), control 611 of 1473 (41.5%), adjusted per study, odds ratio converted to relative risk, 4-5 weeks, logistic regression.
risk of COVID-19 case, 23.2% lower, RR 0.77, p = 0.002, treatment 80 of 181 (44.2%), control 611 of 1473 (41.5%), adjusted per study, odds ratio converted to relative risk, 2-3 weeks, logistic regression.
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.