Displaying 20 results from an estimated 300 matches similar to: "SPLUS Seqtrial vs. R Packages for sequential clinical trials designs"
2003 Jul 10
1
group sequential and adaptive designs
Hello R users,
I am looking for R (or S) code related to group sequential or adaptive
designs for clinical trials. (The most prominent examples are the designs of
Pocock or O'Brien/Fleming, the alpha-spending function approach, or Fisher's
combination test and the inverse normal method.) I am particularly interested in
the calculation of the critical boundaries, the handling of spending
2003 Oct 28
1
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
2011 May 31
0
Finding the adjusted confidence intervals in a group sequential trials (akin to GroupSeq), but in a simulation setting
Hi there,
I want to find the adjusted confidence intervals in group sequential trials
in a simulation setting. GroupSeq provides me with what I am looking for in
an interactive setting, but I am not sure how to make it work in a
simulation setting so that it produces a series of adjusted confidence
intervals for a series of Z-statistics that I provide it without me having
to enter each
2017 Sep 24
2
gsDesign Pocock & OBF boundary
Sorry for messed up text. Here it goes again:
I am learning to use the gsDesign package.
I have a question about Pocock and OBF boundary. As far as I can understand, these 2 boundaries require equal spacing between interim analyses (maybe this is not correct?). But looks like I can still use gsDesign to run an analysis based on unequal spacing:?
>
2017 Sep 22
2
gsDesign Pocock & OBF boundary
Hi,
I am learning to use your gsDesign package!?I have a question about Pocock and OBF boundary. As far as Iunderstand, these 2 boundaries require equal spacing between interim analyses(maybe this is not correct?). But I can still use gsDesign to run an analysisbased on unequal spacing:?gsDesign(k=2,test.type=2,timing=c(0.75,1),alpha=0.05,sfu='Pocock')Symmetrictwo-sided group sequential
2017 Sep 24
0
gsDesign Pocock & OBF boundary
Still failed.
The first secret is in your email program settings, to use Plain Text format (at least for emails you send to this mailing list).
The second secret tool to use is the reprex package to let you verify that your code example will do on our computers what it is doing on your computer before you send it to us. That will also involve giving us some sample data or referencing some data
2017 Sep 23
0
gsDesign Pocock & OBF boundary
> On 23 Sep 2017, at 01:32, array chip via R-help <r-help at r-project.org> wrote:
>
> Hi,
>
> I am learning to use your gsDesign package! I have a question about Pocock and OBF boundary. As far as Iunderstand, these 2 boundaries require equal spacing between interim analyses(maybe this is not correct?). But I can still use gsDesign to run an analysisbased on unequal
2008 Oct 28
1
group sequential analysis - stopping for futility
Hello -
I am wondering if anyone has written some R code to calculate futility
bounds for a group sequential analysis of clinical trials data. The
library ldbounds has a function 'bounds' which calculates the
effectiveness stopping bounds for various spending functions, but it does
not appear to do the same for futility (sometimes called the 'inner
wedge').
Thanks for
2011 Aug 04
1
Multiple endpoint (possibly group sequential) sample size calculation
Hello everyone,
I need to do a sample size calculation. The study two arms and two endpoints. The two arms are two different cancer drugs and the two endpoints reflect efficacy (based on progression free survival) and toxicity.
Until now, I have been trying to understand this in terms of a one-arm design, where the acceptable rate of efficacy might be 0.40, the unacceptable rate of efficacy
2007 Jun 11
8
R vs. Splus in Pharma/Devices Industry
Following up to some extent on Friday's discussion regarding the
'validation' of R, could I ask the list group's opinion on possible
advantages of R over Splus from a pharma/devices perspective? I wish to
exclude the obvious price difference, which doesn’t seem to carry as much
weight as I would have thought. Besides, I have noticed many former Splus
users gravitating towards R,
2010 Feb 19
1
BMDP and SAS (was R in clinical trials)
I used both BMDP and SAS in my earlier years, side by side. At that
time the BMDP statistical methods were much more mature and
comprehensive: we treated them as the standard when the two packages
disagreed. (It was a BMDP manual that clearly explained to me what the
hypothesis of "Yate's weighted mean test" is, something SAS decided to
call "type III" and eternally
2002 Sep 13
0
Sample size for factorial clinical trials with survival endpoints
Dear All,
I am looking an R version of the "Computer program for sample size and
power calculations in the design of multi-arm and factorial clinical trials
with survival endpoints".
Best regards,
Giovanni Parrinello
P.S.: in the meantime I am preparing a summary for my preceeding question
about time-varying covariates in the Cox model and
I thank Frank Harrell, Chuck Cleland,
2006 Oct 04
0
[OT] Survival and Function as co-primary endpoints in clinical trials. How to simulate in R ?
Dear R-Helpers,
Apologies in advance as this is partly (widely ?) OT. Not sure where to
ask, R is my favorite computer tool (no kidding) and there are plenty of
knowledgable and helpful people on the list.
Background: There are discussions among experts and regulatory
authorities (cf guideline
http://www.emea.europa.eu/pdfs/human/ewp/056598en.pdf) that, in for
example Amyotrophic Lateral
2010 Apr 27
1
Randomization for block random clinical trials
Hi,
I’m new to R (just installed today) and I’m trying to figure out how to do
stratified randomisation using it. My google search expedition has lead me
to believe that blockrand package will most probably be the answer to it.
I’ve played around with blockrand for awhile and tried the sample code:
library(blockrand)
##stratified by sex
male <- blockrand(n=100,
2009 Jan 11
2
R, clinical trials and the FDA
I hope that Marc doesn't mind, but I felt that part of his recent post
was important enough to deserve it's own subject line rather then
being lost in a 60-msg-long thread...
On Sun, Jan 11, 2009 at 10:08 AM, Marc Schwartz
<marc_schwartz at comcast.net> wrote:
...
I strongly believe that the comments regarding R and the FDA are overly
negative and pessimistic.
The hurdles to
2011 Nov 14
1
gsDesign
I'm trying to use gsDesign for a noninferiority trial with binary
endpoint. Did anyone know how to specify the trial with different sample
sizes for two treatment groups? Thanks in advance!
[[alternative HTML version deleted]]
2002 Mar 22
0
sequential t-test - replies
[my original message to s-news & r-help is attached ]
No one possessed or knew of any S/R code for the sequential t-test. Also
it doesn't appear in the SAS index.
One or two suggested obtaining the S+ seqtrial software which may (or may
not) cover this, but this seemed to be a bit of a "hammer to crack a nut".
I have written a function based on the treatment in Wetheril
2009 Sep 27
3
CRAN (and crantastic) updates this week
CRAN (and crantastic) updates this week
New packages
------------
* bdoc (1.0)
Michael Anderson
http://crantastic.org/packages/bdoc
This package contains a function that will classify DNA barcodes as
well as a few test and reference data sets.
* bdsmatrix (1.0)
Terry Therneau
http://crantastic.org/packages/bdsmatrix
This is a special case of sparse matrices, used by coxme and
2007 Jun 06
0
R package: Mchtest - Monte Carlo hypothesis testing allowing Sequential Stopping
Hi,
This is an announcement for a package that has been up on CRAN since March 2006 but was never announced.
The package is Mchtest - for Monte Carlo hypothesis tests allowing sequential stopping. The idea is to use the sequential probability ratio test boundaries to stop resampling for a Monte Carlo hypothesis test such as a bootstrap or permutation test. This means that you will take many
2007 Jun 06
0
R package: Mchtest - Monte Carlo hypothesis testing allowing Sequential Stopping
Hi,
This is an announcement for a package that has been up on CRAN since March 2006 but was never announced.
The package is Mchtest - for Monte Carlo hypothesis tests allowing sequential stopping. The idea is to use the sequential probability ratio test boundaries to stop resampling for a Monte Carlo hypothesis test such as a bootstrap or permutation test. This means that you will take many