Statistical Programs for Clinical Trials

Programs for Computing Group Sequential Boundaries Using the Lan-DeMets Method, Version 2.1, Last Update: 11/17/03

Abstract Documentation Documentation Binaries/Source Binaries and Source Authors
FORTRAN programs for the computation of boundaries and exit probabilities in the sequential analysis of clinical trials are described. The computations are appropriate for any trial based on normally distributed test statistics with independent increments, including those in which patients give a single continuous or binary response, survival studies, and certain longitudinal designs. Interim analyses need not be equally spaced, and their number need not be specified in advance. In addition to boundaries, power computations, probabilities associated with a given set of boundaries, and confidence intervals can be computed. An explanation of the input and output, along with some verbatim transcripts of interactive sessions are included. Some theoretical background and description of the numerical computations is provided in the documentation appendix. The program and this documentation are updates of earlier versions.
  • Windows
    • New!Microsoft Windows graphical user interface for ld98. Download the ZIP file, create a new directory (e.g. WinLD) and unzip the contents into the new directory. Program name is winld.exe. Create a shortcut on your Windows Desktop for easy access.

  • Unix
    • Download the Solaris (SunOS 5.6) SPARC executable ld98 (ELF 32-bit MSBVersion 1, statically linked, not stripped)
    • Download the SunOS 4.1 SPARC executable ldbnds.sun (demand paged, dynamically linked)
    • Download the Solaris (SunOS 5.6) SPARC executable ldbnds.sol (ELF 32-bit MSB Version 1, statically linked, not stripped)
    • Download the FORTRAN source ld98.f
    • Download the FORTRAN source ldbnds.f
    • Download the Makefile

David M. Reboussin
Department of Public Health
Bowman Gray School of Medicine
Winston-Salem, NC 27157
David L. DeMets
Department of Biostatistics and Medical Informatics, Department of Statistics
University of Wisconsin
Madison, WI 53706
KyungMann Kim
Department of Biostatistics and Medical Informatics, Department of Statistics
University of Wisconsin
Madison, WI 53706
K. K. Gordon Lan
Pfizer Central Research
Groton, CT 06340

Program for Computing Sample Size, Version 1.0, Last Update: 2/25/04

InstructionsInstructions ProgramProgram Reference
SampleSize was developed using Sun's Java2 programming language. It is being distributed as a Java Archive File (JAR), which should execute on most MS Windows systems without any additional software installation. Simply download the jar into a folder (e.g. c:\SampleSize) and create a shortcut to it on your desktop. However, if it does not run you will need to download the Java2 Runtime Environment from Sun's Java web site. A link to the download area is provided in the "Program" area. Also, since this program is in Java, you can run it on any system that has a Java Runtime Environment (v1.4.1 or higher). Visit Sun's Java web site for more information.

If you need to include the output from this program in a word processor, it is recommended that you "Print" to an Adobe PDF file and then use Acrobat to copy the table (using "Select Table") or the graph (using "Select Image") and then paste either into your document.
  • New! SampleSize Download the SampleSize Java Archive (JAR) File. UPDATED 3/10/04; v1.01 - Finer calculation resolution, version appears in menu bar and printout.
  • Download the SampleSize manual.
  • If SampleSize does not run, you may need a new version of Java. Download the Java2 Windows Runtime Environment v1.4.2. Select the "Windows Installation, Multi-language" download. After clicking the "Download" link for the JRE, a dialog box pops up -- choose the "Open" option. This will prompt you through the steps to download. (The letters "iftw" mean "install from the web".) If you wish to install the package offline, select the "Windows Offline Installation, Multi-language" download and save the file to disk. Install per instructions
  • Download the Java2 Runtime Environment. Select the J2SE v1.4.2 or higher JRE. Install per instructions
Friedman LM, Furberg CD, DeMets DL: Fundamentals of Clinical Trials, Third Edition, New York, 1998, Springer-Verlag