Step-forward randomization in multicenter emergency treatment clinical trials.

The authors present a new centralized randomization method for multicenter emergency treatment clinical trials. With this step-forward method, treatment randomization for the next subject is performed immediately after the enrollment of the current subject. This design ensures the readiness of the treatment assignment for each subject at the point of study enrollment, and it simultaneously provides effective control on treatment assignments balance and distributions of covariates. The authors also discuss procedures of the step-forward randomization method along with its implementation for two National Institute of Neurological Disorders and Stroke-funded multicenter acute stroke trials, one double-blinded and one open-labeled. Advantages and limitations are presented based on experience gained in these two trials. (c) 2010 by the Society for Academic Emergency Medicine.