title: The pursuit of balance: An overview of covariate-adaptive randomization techniques in clinical trials.
abstract: Randomization is fundamental to the design and conduct of clinical trials. Simple randomization ensures independence among subject treatment assignments and prevents potential selection biases, yet it does not guarantee balance in covariate distributions across treatment groups. Ensuring balance in important prognostic covariates across treatment groups is desirable for many reasons. A broad class of randomization methods for achieving balance are reviewed in this paper; these include block randomization, stratified randomization, minimization, and dynamic hierarchical randomization. Practical considerations arising from experience with using the techniques are described. A review of randomization methods used in practice in recent randomized clinical trials is also provided.
authors.affiliation: Takeda Development Center Americas, Inc., Deerfield, IL 60015, USA. Electronic address: yzlinn@gmail.com.
authors.forename: Yunzhi
authors.initials: Y
authors.lastname: Lin
authors.affiliation: AbbVie Inc., North Chicago, IL 60064, USA.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhu
authors.affiliation: Deerfield Institute, New York, NY 10017, USA.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Su
mesh_terms: D003198:Computer Simulation; D006801:Humans; D011897:Random Allocation; D016032:Randomized Controlled Trials as Topic / Q000379:methods* / Q000592:standards; D012107:Research Design / Q000592:standards; D015983:Selection Bias
keywords: Block randomization; Clinical trials; Dynamic hierarchical randomization; Minimization; Randomization; Stratified randomization