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The Role of Randomization in Bayesian and Frequentist Design of Clinical Trial

  • Paola Berchialla
  • Dario Gregori
  • Ileana Baldi


A key role in inference is played by randomization, which has been extensively used in clinical trials designs. Randomization is primarily intended to prevent the source of bias in treatment allocation by producing comparable groups. In the frequentist framework of inference, randomization allows also for the use of probability theory to express the likelihood of chance as a source for the difference of end outcome. In the Bayesian framework, its role is more nuanced. The Bayesian analysis of clinical trials can afford a valid rationale for selective controls, pointing out a more limited role for randomization than it is generally accorded. This paper is aimed to offer a view of randomization from the perspective of both frequentist and Bayesian statistics and discussing the role of randomization also in theoretical decision models.


Clinical trials Bayesian inference Frequentist inference Randomization 



This research was supported by the University of Torino, Grant No. BERP_RILO_17_01.


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© Springer Science+Business Media B.V., part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of Clinical and Biological SciencesUniversity of TorinoTurinItaly
  2. 2.Unit of Biostatistics, Epidemiology and Public Health, Department of Cardiac, Thoracic and Vascular SciencesUniversity of PadovaPaduaItaly

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