Randomization and Masking
Stroke
ALTERNATION, STROKE
Participants were randomly allocated to receive either TXA or matching placebo in a 1:1 ratio via a centralized, Web-based, secure procedure, with minimization for key prognostic factors (age, sex, National Institutes of Health Stroke Scale [NIHSS] score, and use of one of NOAC-specific reversal agents idarucizumab or andexanet alfa). To avoid predictable alternation of treatment allocation, and thus potential loss of allocation concealment, participants were allocated with a probability of 80% to the treatment group that would minimize between-group imbalances of the minimization factors. The randomization sequence was generated by the Clinical Trial Unit Basel. Participants, investigators involved in study assessments, and independent physicians involved in patient management were all masked to treatment allocation.The pharmacy of the University Hospital Basel prepared, stored, and distributed (in numbered supplies) the investigational product to study sites in externally indistinguishable sealed treatment packs, each labeled with a unique number and containing either TXA or placebo (0.9% sodium chloride) in nonidentical commercial off-the-shelf ampoules as solution for intravenous infusion. Participants were assigned a treatment pack number via the randomization procedure. After randomization, the assigned sealed treatment pack was handed to an unmasked nurse not involved in study assessments, who unsealed it, added the ampoules into bags of normal saline, and administered the appropriately labeled masked infusion bags to the participant.