Randomization in clinical studies

• Main Authors: Chi-Yeon Lim, Junyong In
• Format: Article
• Language: English
• Published: Korean Society of Anesthesiologists 2019-06-01
• Series: Korean Journal of Anesthesiology
• Subjects: adaptive randomization; minimization; random allocation; randomization; randomized controlled trial; restrictive randomization; simple randomization; stratified randomization
• Online Access: http://ekja.org/upload/pdf/kja-19049.pdf

Randomized controlled trial is widely accepted as the best design for evaluating the efficacy of a new treatment because of the advantages of randomization (random allocation). Randomization eliminates accidental bias, including selection bias, and provides a base for allowing the use of probability theory. Despite its importance, randomization has not been properly understood. This article introduces the different randomization methods with examples: simple randomization; block randomization; adaptive randomization, including minimization; and response-adaptive randomization. Ethics related to randomization are also discussed. The study is helpful in understanding the basic concepts of randomization and how to use R software.