On the second role of the random element in minimization.
Although the main reason for adding a random element at every step of minimization procedure is to reduce predictability of the upcoming treatment assignments in single-center open-label trials, there is another reason for its use, applicable to double-blind trials. Adding the random element at every allocation step allows one to avoid a fully deterministic sequence of treatment assignments for sequences of covariates for which at every allocation step one of the treatments leads to a better balance in covariates than all other treatments. An example of such a sequence is provided in this communication.
Kuznetsova
Olga M
OM
Merck, Sharp and Dohme, Corp, PO Box 2000, RY34-316, Rahway, NJ 07065-0900, USA. olga_kuznetsova@merck.com
D000465:Algorithms; D006801:Humans; D016032:Randomized Controlled Trials as Topic / Q000379:methods*; D015983:Selection Bias