A multicenter randomized trial to assess the efficacy of CONvalescent plasma therapy in patients with Invasive COVID-19 and acute respiratory failure treated with mechanical ventilation: the CONFIDENT trial protocol

摘要

We used blocked randomization to form the allocation list for the two comparison groups. We used a computer random number generator, R software, to select random permuted blocks with a block size of four and an equal allocation ratio. The randomization process was stratified according to the delay from tracheal intubation to inclusion (<= 48 h and between 48 h and 5 days).