R help - Oct 2003 - Summary : Whitehead's group sequential procedures

Dear List,

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
Secr?tariat Scientifique du CEDIT	Fax : +33-(0)1 40 27 55 65
Assistance Publique - H?pitaux de Paris
3, Avenue Victoria, F-75100 Paris RP - France

On Tue, 2003-10-28 at 08:16, Emmanuel Charpentier wrote:
> Dear List,
> 
SNIP
> 4) It has been suggested that I contact Scott Emerson, author of an S 
> package called seqTrials. Does someone has an address for him ?
http://www.biostat.washington.edu/index.php?page=facdir&fullprofile=yes&lastname=Emerson

Be aware that if you do a search on the product, it is called
"S+SeqTrial". The Insightful page for it is at
http://www.insightful.com/products/seqtrial/default.asp

Also, FWIW, there is another book that you might want to look at, simply
as an alternative resource:

http://www.amazon.com/exec/obidos/tg/detail/-/0849303168/
Group Sequential Methods with Applications to Clinical Trials
by Christopher Jennison, Bruce W. Turnbull
CRC Press; (September 15, 1999)
ISBN: 0849303168

Others here may have other references that would also be helpful.

HTH,

Marc Schwartz