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.
Covariate Adjusted Designs for Combining Efficiency, Ethics and Randomness in Normal Response Trials / A. Baldi Antognini; M. Zagoraiou. - STAMPA. - (2010), pp. 17-24. (Intervento presentato al convegno mODa 9: Model-Oriented Data Analysis and Optimum Design tenutosi a Bertinoro, Italy nel 13-18 giugno, 2010).
Covariate Adjusted Designs for Combining Efficiency, Ethics and Randomness in Normal Response Trials
BALDI ANTOGNINI, ALESSANDRO;ZAGORAIOU, MAROUSSA
2010
Abstract
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
