These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Population enrichment designs: case study of a large multinational trial.
    Author: Mehta CR, Gao P.
    Journal: J Biopharm Stat; 2011 Jul; 21(4):831-45. PubMed ID: 21516572.
    Abstract:
    A method is proposed for modifying a group-sequential clinical trial by restricting future enrollment to a subgroup and possibly altering the sample size of the subgroup, based on an interim analysis of the data already obtained. The method provides strong control of type 1 error without requiring prespecification of the list of possible subgroups or of the decision rule for selecting among them. Nevertheless, for regulatory submissions it is recommended that the subgroups and decision rule be prespecified. The method is applied to a large cardiology trial in which the subgroups are prespecified and the decision rules for subgroup selection and sample size alteration are based on conditional power. It is shown by simulation that substantial gains in power can be attained if there is a subgroup by treatment interaction.
    [Abstract] [Full Text] [Related] [New Search]