Covariate Adjusted Designs for Combining Efficiency, Ethics and Randomness in Normal Response Trials

  • Alessandro Baldi Antognini
  • Maroussa Zagoraiou
Conference paper
Part of the Contributions to Statistics book series (CONTRIB.STAT.)


This paper deals with the problem of allocating patients to two competing treatments in the presence of covariates in order to achieve a good trade-off between efficiency, ethical concern and randomization. We propose a compound criterion that combines inferential precision and ethical gain by flexible weights depending on the unknown treatment effects. In the absence of treatment-covariate interactions, this criterion leads to a locally optimal allocation which does not depend on the covariates and can be targeted by a suitable implementation of the doubly-adaptive biased coin design aimed at balancing the roles of randomization, ethics and information. Some properties of the suggested procedure are described.


Optimal Allocation Optimal Target Adaptive Design Allocation Proportion Ethical Criterion 
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This research was partly supported by the Italian Ministry for Research (MIUR) PRIN 2007 “Statistical methods for learning in clinical research”.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2010

Authors and Affiliations

  • Alessandro Baldi Antognini
    • 1
  • Maroussa Zagoraiou
    • 1
  1. 1.Department of Statistical SciencesUniversity of BolognaBolognaItaly

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