I recently asked about any R implementations of Whitehead's methods for sequential clinical trials. Here's the summary of answers so far :
1) There is no R public implementation of those methods
2) There exists an interest for such a package, which does things quite different from Lan-deMets paradigm (shortly : Whitehead's methods allows for unplanned interim analyses in any number, while Lan-deMets plans a fixed number of interim analyses at fixed (information) times).
3) I know how to implement simple things : design (with approximations), monitoring and stopping rule. I'm still hacking my way through Whitehead's book to understand his procedures for the distribution of the total number of patients included (which is a random variable) and the final analysis (after study termination).
4) It has been suggested that I contact Scott Emerson, author of an S package called seqTrials. Does someone has an address for him ?
I'll start implementing the simple stuff, trying to create a framework flexible enough to allow generalization. I'll probably plea for help at some time in the future ...
However, don't hold your breath : I'm doing this in my spare time, on top of a busy schedule ...
Emmanuel Charpentier
-- Emmanuel Charpentier Tel : +33-(0)1 40 27 35 98 Secrétariat Scientifique du CEDIT Fax : +33-(0)1 40 27 55 65 Assistance Publique - Hôpitaux de Paris 3, Avenue Victoria, F-75100 Paris RP - France
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