similar to: Sample size for factorial clinical trials with survival endpoints

Hello, I am planning a study with the main point to evaluate the interaction of two treatments, but for ethical reasons one cell is empty, that with patients receaving no treatment at all Treatment B

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

Dear All, I got these results from the example in the function "dbeta": >x <- seq(0, 1, length=21) > dbeta(x, 1, 1) [1] 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Any Idea? TIA Giovanni dr. Giovanni Parrinello Section of Medical Statistics Department of Biosciences University of Brescia 25127 Viale Europa, 11 Brescia Italy Tel: +390303717528 Fax: +390303701157

Dear All, I am looking for an implementation in R of the Appell Hypergeometric function. Any suggestions will be more than appreciated! GP -- dr. Giovanni Parrinello External Lecturer Medical Statistics Unit Department of Biomedical Sciences Viale Europa, 11 - 25123 Brescia Italy Tel: +390303717528 Fax: +390303717488 email: parrinel at med.unibs.it

Dear All, discussing with a statistician of a pharmaceutical company I received this answer about the statistical package that I have planned to use: As R is not a validated software package, we would like to ask if it would rather be possible for you to use SAS, SPSS or another approved statistical software system. Could someone suggest me a 'polite' answer? TIA Giovanni -- dr.

Dear All, I am looking for the library QVF [ NONLINEAR MEASUREMENT ERROR PROGRAMS FOR SAS AND SPLUS ]. TIA Giovanni Parrinello dr. Giovanni Parrinello Medical Statistics Unit Department of Medical Sciences University of Brescia Via Valsabbina, 19 25127 Brescia Italy tel.: +39303717528 fax:+39303701157 E-mail: parrinel at med.unibs.it url: http://www.med.unibs.it/dip/stat/index.html

Last week Giovanni Parrinello posted a message asking why various packages were loaded when he loaded an .Rdata file. Brian Ripley replied saying he thought it was because the saved workspace contained a reference to the namespace of ipred. (Correspondence copied below). This begs the question: how did the reference to the namespace of ipred come to be in the .Rdata file? Brian did say it is

Last week Giovanni Parrinello posted a message asking why various packages were loaded when he loaded an .Rdata file. Brian Ripley replied saying he thought it was because the saved workspace contained a reference to the namespace of ipred. (Correspondence copied below). This begs the question: how did the reference to the namespace of ipred come to be in the .Rdata file? Brian did say it is

Dear All, from some days when I try to update the installed packages I receive this answer: update.packages(ask='graphics') --- Please select a CRAN mirror for use in this session --- Error in as.list(read.dcf(file = file)[1, ]) : indice fuori limite # index out of bound TIA Giovanni PS: I have already tried to solve the problem reinstalling R or changing the options of

Dear All, I would like to find something ( references, code,..) to implement a comparison of three treatments in an observational study using the 'Propensity Score'. Any help is much appreciated. Thanks! Giovanni -- dr. Giovanni Parrinello Department of Biotecnologies Medical Statistics Unit University of Brescia Viale Europa, 11 25123 Brescia email: parrinel at med.unibs.it Phone:

Dear All, can anyone explain this message Error in load("matched2.RData") : Value of SET_STRING_ELT() must be a 'CHARSXP' not a 'builtin'? Have I the possibility to retrieve the data? TIA Giovanni -- dr. Giovanni Parrinello Department of Biotecnologies Medical Statistics Unit University of Brescia Viale Europa, 11 25123 Brescia email: parrinel at med.unibs.it Phone:

latex(s6a2,title="",caption="Baseline vs zonr",file="",label="Base",long=TRUE,landscape=F, middle.bold=TRUE,here=T, + ,size="smaller[5]",outer.size="smaller",Nsize="smaller",midsize="smaller") "latex" is not reconized \as a internalor external command , un programma eseguibile o un file batch. Warning

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

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,

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

Hello Everyone,   I’m a SAS user who has recently become interested in sequential clinical trials designs. I’ve discovered that the SAS based approaches for these designs are either too costly or are “experimental.” So now I’m looking for alternative software. Two programs that seem promising are SPLUS Seqtrial and R.   I recently obtained a 30 day trial for the SPLUS Seqtrial add-on and have

Hello to All. I'd want to use a one-way ANOVA. This means that I have only one factor, with, lets say, 5 levels. I made a dataframe, called "DATA", with two Columns: A, that is my response, and it is "class numerical". B, that defines the different levels of my factor, and it is "class factor". If I want to use a fixed effect model, I know that the formula I have

Dear all: Could anyone please provide some R codes to plot the below survival data to compare two groups (0 vs 1) after 2 simulations (TRL)? need 95% prediction interval on the plot from these 2 trials. I would like to simulate 1000 trials later. Thanks a lot for your great help and consideration! yan TRL ID ECOG BASE PTR8 GROUP POP ST ind 1 1 1 1 2.2636717 0.255634126 1 1 99.4 F 3 1 2 1

Dear all, There have been a variety of discussions on the R list regarding the use of R in clinical trials. The following post from the STATA list provides an interesting opinion regarding why SAS remains so popular in this arena: http://www.stata.com/statalist/archive/2008-01/msg00098.html Regards, -Cody Hamilton

Dear R Fellow-Travellers: What is your recommended way of dealing with a left-censored response (non-detects) in (linear Gaussian) mixed effects models? Specifics: Response is a numeric positive measurement (of volume, actually); but when it falls below some unknown and slightly random value (depending on how the sample is prepared and measured), it cannot be measured and is recorded as 0.