[Development of a Method for Assignment Control in Randomized Controlled Trials]

Randomized controlled trials (RCT) are the most reliable study design for causality estimation in medical research. Proper implementation of the process of randomization is necessary to ensure the reliability of RCT. In order to do so, 1) generation of randomization sequence, 2) allocation concealment, and 3) allocation must be properly implemented. Methods such as the central secretariat method, the envelope method, and the sequentially numbered container method are adopted to secure proper implementation. For investigator-initiated clinical research and relatively small-scale clinical research, the envelope method and the sequentially numbered container method are often adopted because of budgetary reasons, but these methods do not assure the implementation of proper RCT. Therefore, we designed an assignment management note system as a new method to manage the assignment of RCT that can be implemented in small scale clinical research. In this paper, we compare the assignment management note system with the conventional method from the viewpoint of the procedure necessary for the proper implementation of RCT, and discuss the advantages and limitations of the assignment management note system.