On Thu, 10 Jul 2003 14:13:20 +0200 (MEST) Marc Vandemeulebroecke <[EMAIL PROTECTED]> wrote:
> 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 functions > and, most of all, power calculations. All I could find were announcements of > courses or postings related to the S-Plus SeqTrial module. No code. Can > anyone give a hint? > > Many thanks in advance, > Marc > If you get the U. of Wisconsin Biostatistics program ld98 executable, which implements several spending functions in the Lan DeMets paradigm, you can use the S function ldBands and its plot and summary methods, which call ld98. ldBands is in the Hmisc package at http://hesweb1.med.virginia.edu/biostat/s/Hmisc.html ldBands works under Linux/Unix but has not been tested under Windows yet. Get ld98 and its documentation from http://www.medsch.wisc.edu/landemets ldBands makes ld98 easier to use. Examples show how to do power calculations. --- Frank E Harrell Jr Prof. of Biostatistics & Statistics Div. of Biostatistics & Epidem. Dept. of Health Evaluation Sciences U. Virginia School of Medicine http://hesweb1.med.virginia.edu/biostat ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help
