Difference: PowerSampleSize (1 vs. 51)

Revision 51
Changes from r49 to r51
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"
Line: 45 to 45
 

There are a number Wine implementations and Wine front ends available. Our recommendation is not the only approach. Suggestions are welcome.

Added:
>
>
Click here for PlayOnMac instructions.

  (old Macintosh and Linux installation instructions)

Feedback

Revision 49
Changes from r47 to r49
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"
Line: 29 to 29
 

Caution: We know of a bug in one of the third-party tools that we use that causes the program to malfunction when the Windows language is set to something other than English. We are working to replace this tool with one of our own and we apologize for any inconvenience that this problem causes.
Changed:
<
<

Macintosh

ps_icon.jpg PSapp.zip (254 MB)
>
>

Macintosh and Linux

In the past we have tried to supply installation packages that allowed the installation of the PS program in one step. For a number of reasons, this has been a troublesome approach. There are many versions of the OSX and Linux distributions in use. It is difficult to make an installer that works correctly on all of these.
 
Changed:
<
<
We are using a tool called Wineskin ("a tool used to make ports of Windows software to Mac OS X") to install PS on Macinsosh computers. The program has been tested on Macintosh systems running OS X 10.7 ("Lion").
>
>
Our current recommendation is to use the Wine graphical front end programs PlayOnMac (for Macintosh) and PlayOnLinux (for Linux). PlayOnMac and PlayOnLinux are free packages that simplify the installation and use of Windows software on these other platforms.
 
Changed:
<
<
Note: This combination of the PS program and the Windows emulation software needed to make it run on OS X has been tested on a very limited number of systems. It may or may not work on your particular Macintosh system. We appreciate reports of problems that will help to get the program running on more systems.
>
>
The process for installing PS involves 3 steps:
  1. Download and install PlayOnMac or PlayOnLinux as appropriate from the sites linked above.
  2. Download the PS installer (pssetup3.exe)
  3. Run PlayOnMac or PlayOnLinux to install and use the PS program on your computer.
 
Changed:
<
<
To obtain the PS program for Macintosh, click here. The file PSapp.zip (254 MB)will be downloaded to the Downloads folder. Use the Finder to open the Downloads folder and double click on the zip file to expand the program. You will see the expanded PS program with the PS logo. It is customary to store programs in the Applications folder so drag the file there. You can run the PS program by double clicking on the PS icon. If you wish to keep the PS icon on the Dock for easy access then, when the program is running, ctrl-click on the icon, select Options in the pop-up menu, and click "Keep in Dock".
>
>
PlayOnMac and PlayOnLinux inspect the software to be installed and attempt to also install other packages and tools that are necessary for the PS program to run correctly.
 
Changed:
<
<

Linux

ps_icon.jpg pssetup3.exe (3.5 MB) (This is the same installer as for Windows. It depends on the presence of Wine on the installing computer for it and the installed program to function correctly.)
>
>
Wine (originally an acronym for "Wine Is Not an Emulator") is a compatibility layer capable of running Windows applications on several POSIX-compliant operating systems, such as Linux, Mac OSX, & BSD.
 
Changed:
<
<
We have succeeded in running the program on the Linux (Ubuntu) operating system using Wine. You need at least version 1.1.10 of Wine for the program to run correctly and it runs a little better on each subsequent Wine release. We are using it successfully on a number of Linux computers.
>
>
There are a number Wine implementations and Wine front ends available. Our recommendation is not the only approach. Suggestions are welcome.
 
Changed:
<
<
To install Wine on a computer running Ubuntu Linux, use the command sudo apt-get install wine. Then click here or on the icon above to download the PS installer (i.e. pssetup3.exe). Once pssetup3.exe is downloaded, click on it to begin the installation.

The PS program uses the symbol font (symbol.ttf) to render Greek characters. This seems to work correctly with versions of Ubuntu later than 9.10. If you use an earlier version, you will need to obtain that font and install it so that the Greek characters will display correctly. As of version 9.10 of Ubuntu and Kubuntu there is a package available called "ttf-symbol-replacement" which is described as a "Free font with the same metrics as Symbol".
>
>
(old Macintosh and Linux installation instructions)
 

Feedback

We are interested in feedback. If you have any questions or comments about our software please send email to dale.plummer@vanderbilt.edu. It will be appreciated.
Revision 47
Changes from r45 to r47
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"
Line: 21 to 21
  The PS program runs on the Microsoft Windows operating systems (Windows XP and later). We have also installed the program on Linux and Macintosh computers using a program called Wine that facilitates running Windows software on other operating systems.

Windows

Changed:
<
<
ps_icon.jpg pssetup3.exe (3.3 MB)
>
>
ps_icon.jpg pssetup3.exe (3.5 MB)
 
Changed:
<
<
To obtain the software, click PS (3.3 MB) and instruct your browser to download the file to a folder on your computer. To avoid problems with the installation process, it is helpful if the target folder is empty. A file called pssetup3.exe will be downloaded to this location. Run pssetup3.exe to extract the needed files and install the program.
>
>
To obtain the software, click PS (3.5 MB) and instruct your browser to download the file to a folder on your computer. To avoid problems with the installation process, it is helpful if the target folder is empty. A file called pssetup3.exe will be downloaded to this location. Run pssetup3.exe to extract the needed files and install the program.
 

To run the PS program after it has been installed, click the Start button, select Programs and then click PS. Click the Overview button for an introduction to the program and instruction on its use. PS is a self-documented program with extensive interactive help.

Caution: We know of a bug in one of the third-party tools that we use that causes the program to malfunction when the Windows language is set to something other than English. We are working to replace this tool with one of our own and we apologize for any inconvenience that this problem causes.

Macintosh

Changed:
<
<
ps_icon.jpg PSapp.zip (78.6 MB)
>
>
ps_icon.jpg PSapp.zip (254 MB)
 

We are using a tool called Wineskin ("a tool used to make ports of Windows software to Mac OS X") to install PS on Macinsosh computers. The program has been tested on Macintosh systems running OS X 10.7 ("Lion").

Note: This combination of the PS program and the Windows emulation software needed to make it run on OS X has been tested on a very limited number of systems. It may or may not work on your particular Macintosh system. We appreciate reports of problems that will help to get the program running on more systems.
Changed:
<
<
To obtain the PS program for Macintosh, click here. The file PSapp.zip (78.6 MB)will be downloaded to the Downloads folder. Use the Finder to open the Downloads folder and double click on the zip file to expand the program. You will see the expanded PS program with the PS logo. It is customary to store programs in the Applications folder so drag the file there. You can run the PS program by double clicking on the PS icon. If you wish to keep the PS icon on the Dock for easy access then, when the program is running, ctrl-click on the icon, select Options in the pop-up menu, and click "Keep in Dock".
>
>
To obtain the PS program for Macintosh, click here. The file PSapp.zip (254 MB)will be downloaded to the Downloads folder. Use the Finder to open the Downloads folder and double click on the zip file to expand the program. You will see the expanded PS program with the PS logo. It is customary to store programs in the Applications folder so drag the file there. You can run the PS program by double clicking on the PS icon. If you wish to keep the PS icon on the Dock for easy access then, when the program is running, ctrl-click on the icon, select Options in the pop-up menu, and click "Keep in Dock".
 

Linux

Changed:
<
<
ps_icon.jpg pssetup3.exe (3.3 MB) (This is the same installer as for Windows. It depends on the presence of Wine on the installing computer for it and the installed program to function correctly.)
>
>
ps_icon.jpg pssetup3.exe (3.5 MB) (This is the same installer as for Windows. It depends on the presence of Wine on the installing computer for it and the installed program to function correctly.)
 

We have succeeded in running the program on the Linux (Ubuntu) operating system using Wine. You need at least version 1.1.10 of Wine for the program to run correctly and it runs a little better on each subsequent Wine release. We are using it successfully on a number of Linux computers.
Revision 45
Changes from r43 to r45
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"

PS: Power and Sample Size Calculation

Changed:
<
<
PS: Power and Sample Size Calculation version 3.0, 2009
>
>
PS: Power and Sample Size Calculation version 3.1.2, 2014
 

by William D. Dupont and Walton D. Plummer, Jr.
Line: 39 to 39
  To obtain the PS program for Macintosh, click here. The file PSapp.zip (78.6 MB)will be downloaded to the Downloads folder. Use the Finder to open the Downloads folder and double click on the zip file to expand the program. You will see the expanded PS program with the PS logo. It is customary to store programs in the Applications folder so drag the file there. You can run the PS program by double clicking on the PS icon. If you wish to keep the PS icon on the Dock for easy access then, when the program is running, ctrl-click on the icon, select Options in the pop-up menu, and click "Keep in Dock".

Linux

Changed:
<
<
ps_icon.jpg pssetup3.exe (3.3 MB)
>
>
ps_icon.jpg pssetup3.exe (3.3 MB) (This is the same installer as for Windows. It depends on the presence of Wine on the installing computer for it and the installed program to function correctly.)
 

We have succeeded in running the program on the Linux (Ubuntu) operating system using Wine. You need at least version 1.1.10 of Wine for the program to run correctly and it runs a little better on each subsequent Wine release. We are using it successfully on a number of Linux computers.
Line: 97 to 97
 
META FILEATTACHMENT attr="h" comment="" date="1107901832" name="ps_icon.ico" path="ps_icon.ico" size="766" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="" date="1107960561" name="ps_icon.jpg" path="ps_icon.jpg" size="654" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="Online documentation" date="1184257097" name="pshelp.chm" path="pshelp.chm" size="43439" user="DalePlummer" version="1.1"
Changed:
<
<
META FILEATTACHMENT attachment="pssetup3.exe" attr="" comment="Power and Sample Size program version 3.0.43" date="1298065902" name="pssetup3.exe" path="pssetup3.exe" size="3379200" stream="IO::File=GLOB(0x95a0498)" tmpFilename="/tmp/TOGOL0Uric" user="DalePlummer" version="15"
>
>
META FILEATTACHMENT attachment="pssetup3.exe" attr="" comment="" date="1403705836" name="pssetup3.exe" path="pssetup3.exe" size="3530752" user="DalePlummer" version="16"
 
META FILEATTACHMENT attachment="PS_icon.jpg" attr="" comment="" date="1314024289" name="PS_icon.jpg" path="PS_icon.jpg" size="912" stream="IO::File=GLOB(0x95ce6e4)" tmpFilename="/tmp/wTDniBFwro" user="DalePlummer" version="1"
META FILEATTACHMENT attachment="PS_icon.png" attr="" comment="" date="1314024311" name="PS_icon.png" path="PS_icon.png" size="1335" stream="IO::File=GLOB(0x8cf0768)" tmpFilename="/tmp/o91OGoCf3Q" user="DalePlummer" version="1"
META FILEATTACHMENT attachment="PS_icon.ico" attr="" comment="" date="1314024342" name="PS_icon.ico" path="PS_icon.ico" size="3262" stream="IO::File=GLOB(0x95dad50)" tmpFilename="/tmp/rmLFrPc2eY" user="DalePlummer" version="1"
Revision 43
Changes from r41 to r43
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"
Line: 8 to 8
 

by William D. Dupont and Walton D. Plummer, Jr.
Added:
>
>
Online Help
 

PS is an interactive program for performing power and sample size calculations that may be downloaded for free. It can be used for studies with dichotomous, continuous, or survival response measures. The alternative hypothesis of interest may be specified either in terms of differing response rates, means, or survival times, or in terms of relative risks or odds ratios. Studies with dichotomous or continuous outcomes may involve either a matched or independent study design. The program can determine the sample size needed to detect a specified alternative hypothesis with the required power, the power with which a specific alternative hypothesis can be detected with a given sample size, or the specific alternative hypotheses that can be detected with a given power and sample size.
Line: 90 to 92
 

We are grateful to Gordon R. Bernard for his support and to Yuwei Zhu for her assistance in editing this program.
Changed:
<
<
Creative Commons License
PS: Power and Sample Size Calculation by William D. Dupont is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 United States License.
>
>
Creative Commons License
This web page and the PS: Power and Sample Size Calculation program by William D. Dupont and W. Dale Plummer, Jr. is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 United States License.
 

META FILEATTACHMENT attr="h" comment="" date="1107901832" name="ps_icon.ico" path="ps_icon.ico" size="766" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="" date="1107960561" name="ps_icon.jpg" path="ps_icon.jpg" size="654" user="DalePlummer" version="1.1"
Revision 41
Changes from r39 to r41
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"
Line: 30 to 30
 

Macintosh

ps_icon.jpg PSapp.zip (78.6 MB)
Changed:
<
<
We are using a tool called Wineskin ("a tool used to make ports of Windows software to Mac OS X") to install PS on Macinsosh computers. The program has been tested on Macintosh systems running OS X 10.7 ("Lion").
>
>
We are using a tool called Wineskin ("a tool used to make ports of Windows software to Mac OS X") to install PS on Macinsosh computers. The program has been tested on Macintosh systems running OS X 10.7 ("Lion").

Note: This combination of the PS program and the Windows emulation software needed to make it run on OS X has been tested on a very limited number of systems. It may or may not work on your particular Macintosh system. We appreciate reports of problems that will help to get the program running on more systems.
 

To obtain the PS program for Macintosh, click here. The file PSapp.zip (78.6 MB)will be downloaded to the Downloads folder. Use the Finder to open the Downloads folder and double click on the zip file to expand the program. You will see the expanded PS program with the PS logo. It is customary to store programs in the Applications folder so drag the file there. You can run the PS program by double clicking on the PS icon. If you wish to keep the PS icon on the Dock for easy access then, when the program is running, ctrl-click on the icon, select Options in the pop-up menu, and click "Keep in Dock".
Revision 39
Changes from r37 to r39
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"
Changed:
<
<

PS: Power and Sample Size Calculation

PS: Power and Sample Size Calculation ps_icon.jpg Get PS (3.3 MB) version 3.0, 2009
>
>

PS: Power and Sample Size Calculation

 
Changed:
<
<
Release Notes
>
>
PS: Power and Sample Size Calculation version 3.0, 2009
 
Changed:
<
<
by William D. Dupont and Walton D. Plummer, Jr.
>
>
by William D. Dupont and Walton D. Plummer, Jr.
 

PS is an interactive program for performing power and sample size calculations that may be downloaded for free. It can be used for studies with dichotomous, continuous, or survival response measures. The alternative hypothesis of interest may be specified either in terms of differing response rates, means, or survival times, or in terms of relative risks or odds ratios. Studies with dichotomous or continuous outcomes may involve either a matched or independent study design. The program can determine the sample size needed to detect a specified alternative hypothesis with the required power, the power with which a specific alternative hypothesis can be detected with a given sample size, or the specific alternative hypotheses that can be detected with a given power and sample size.

The PS program can produce graphs to explore the relationships between power, sample size and detectable alternative hypotheses. It is often helpful to hold one of these variables constant and plot the other two against each other. The program can generate graphs of sample size versus power for a specific alternative hypothesis, sample size versus detectable alternative hypotheses for a specified power, or power versus detectable alternative hypotheses for a specified sample size. Linear or logarithmic axes may be used for either axes. Multiple curves can be plotted on a single graphic.
Changed:
<
<
Downloading and Installing the Software
>
>

Downloading and Installing the PS Software

 
Changed:
<
<
The PS program is freely available on the Internet. To obtain this software on your computer click PS (3.3 MB). Instruct your browser to download the file to a folder on your computer. A file called pssetup3.exe will be downloaded to this location. Run pssetup3.exe to extract the needed files and install the program.
>
>
The PS program runs on the Microsoft Windows operating systems (Windows XP and later). We have also installed the program on Linux and Macintosh computers using a program called Wine that facilitates running Windows software on other operating systems.
 
Changed:
<
<
The program runs on the Microsoft Windows operating systems ( Windows 2000 and later).
>
>

Windows

ps_icon.jpg pssetup3.exe (3.3 MB)
 
Changed:
<
<
Caution: As of 08 Jun 2009 we know of a bug in one of the third-party tools that we use that causes the program to malfunction when the Windows language is set to something other than English. We are working to replace this tool with one of our own and we apologize for any inconvenience that this problem causes.
>
>
To obtain the software, click PS (3.3 MB) and instruct your browser to download the file to a folder on your computer. To avoid problems with the installation process, it is helpful if the target folder is empty. A file called pssetup3.exe will be downloaded to this location. Run pssetup3.exe to extract the needed files and install the program.
 

To run the PS program after it has been installed, click the Start button, select Programs and then click PS. Click the Overview button for an introduction to the program and instruction on its use. PS is a self-documented program with extensive interactive help.
Changed:
<
<
We have had some luck running the program on the Linux (Ubuntu) operating system using Wine. You need at least version 1.1.10 of Wine for the program to run correctly and it runs a little better on each subsequent Wine release. Note that we don't guarantee anything if you try to run PS on Linux. It can be a little unstable sometimes, but we are using it successfully on a couple of Linux computers. To install Wine on a computer running Ubuntu Linux, use the command sudo apt-get install wine. Then click on the icon above to download the PS installer (i.e. pssetup3.exe). Once pssetup3.exe is downloaded, click on it to begin the installation.
>
>
Caution: We know of a bug in one of the third-party tools that we use that causes the program to malfunction when the Windows language is set to something other than English. We are working to replace this tool with one of our own and we apologize for any inconvenience that this problem causes.

Macintosh

ps_icon.jpg PSapp.zip (78.6 MB)

We are using a tool called Wineskin ("a tool used to make ports of Windows software to Mac OS X") to install PS on Macinsosh computers. The program has been tested on Macintosh systems running OS X 10.7 ("Lion").

To obtain the PS program for Macintosh, click here. The file PSapp.zip (78.6 MB)will be downloaded to the Downloads folder. Use the Finder to open the Downloads folder and double click on the zip file to expand the program. You will see the expanded PS program with the PS logo. It is customary to store programs in the Applications folder so drag the file there. You can run the PS program by double clicking on the PS icon. If you wish to keep the PS icon on the Dock for easy access then, when the program is running, ctrl-click on the icon, select Options in the pop-up menu, and click "Keep in Dock".

Linux

ps_icon.jpg pssetup3.exe (3.3 MB)

We have succeeded in running the program on the Linux (Ubuntu) operating system using Wine. You need at least version 1.1.10 of Wine for the program to run correctly and it runs a little better on each subsequent Wine release. We are using it successfully on a number of Linux computers.

To install Wine on a computer running Ubuntu Linux, use the command sudo apt-get install wine. Then click here or on the icon above to download the PS installer (i.e. pssetup3.exe). Once pssetup3.exe is downloaded, click on it to begin the installation.
 

The PS program uses the symbol font (symbol.ttf) to render Greek characters. This seems to work correctly with versions of Ubuntu later than 9.10. If you use an earlier version, you will need to obtain that font and install it so that the Greek characters will display correctly. As of version 9.10 of Ubuntu and Kubuntu there is a package available called "ttf-symbol-replacement" which is described as a "Free font with the same metrics as Symbol".
Added:
>
>

Feedback

  We are interested in feedback. If you have any questions or comments about our software please send email to dale.plummer@vanderbilt.edu. It will be appreciated.
Changed:
<
<
Study Designs That Can Be Evaluated By This Program
>
>

Study Designs That Can Be Evaluated By This Program

 

  1. Case-Control Studies -- Corrected and uncorrected chi-squared contingency table tests, Fisher’s exact-test: The method of Schlesselman (1982) is used for studies with independent case and control groups that will be analyzed using an uncorrected chi-squared test; the method of Casagrande et al. (1978) is used for independent studies that will be analyzed using continuity corrected chi-squared statistics or Fisher’s exact-test. When the case and control sample sizes are unequal, PS uses the generalization of Casagrande’s method proposed by Fleiss (1981). The alternative hypotheses may be specified in terms of odds ratios or exposure prevalence rates.
  2. Matched Case-Control Studies -- McNemar’s Test: The method of Dupont (1988) is used for studies with paired or matched cases and controls. The alternative hypotheses are specified in terms of odds ratios.
Line: 39 to 56
 
  1. Linear Regression (2 Treatments) -- Comparing the slopes and intercepts of two independent linear regressions: The approach of Dupont and Plummer (1998) is used to design studies in which we wish to determine whether the slopes or intercepts of two independent regression lines differ by a given amount. The values of the independent (x) variables of the regression lines may either be specified by the investigator or determined observationally when the study is performed. In the latter case, the investigator must estimate the standard deviations of the independent variables.
  2. Survival Studies -- Evaluating independent cohorts using the log-rank test: The approach of Schoenfeld and Richter (1982) is used. The ratio of the number of control subjects per experimental subject in the cohorts being compared may be specified by the user. The alternative hypotheses are specified in terms of the hazard ratio for control subjects relative to experimental subjects or the median survival times for control and experimental subjects.
  3. Continuous Response Measures in Two Groups -- Paired and independent t-tests: The approach of Dupont and Plummer (1990) is used for paired and independent samples. The ratio of the number of control subjects per experimental subject may be specified by the user. This method produces results that are in close agreement with those of Pearson and Hartley (1970).
Deleted:
<
<
References
 
Added:
>
>

References

 
  1. Casagrande JT, Pike MC, Smith PG: "An Improved Approximate Formula for Calculating Sample Sizes for Comparing Two Binomial Distributions", Biometrics, 1978; 34:483-486.
  2. Dupont, WD: "Power Calculations for Matched Case-Control Studies", Biometrics, 1988; 44:1157-1168.
  3. Dupont WD, Plummer WD: "Power and Sample Size Calculations: A Review and Computer Program", Controlled Clinical Trials 1990; 11:116-28.
Line: 53 to 70
 
  1. Visual Components Sybase Inc. First Impression Active X User's Guide: High Performance Software for Charting Data for Microsoft Visual Basic, Visual C++, and Other Languages. Version 5.0. Overland Park, KS: Visual Components Sybase Inc.
  2. Mantel, N., & Haenszel, W. (1959) Statistical aspects of the analysis of data from retrospective studies of disease. Journal of the National Cancer Institute, 22, 719-748.
  3. Dupont, WD (2008). Statistical Modeling for Biomedical Researchers, 2nd Edition. Cambridge, U.K.: Cambridge University Press.
Changed:
<
<
Suggested citation
>
>

Suggested citation

 

Dupont WD, Plummer WD: 'Power and Sample Size Calculations: A Review and Computer Program', Controlled Clinical Trials 1990; 11:116-28.
Line: 61 to 79
 

Dupont WD, Plummer WD: 'Power and Sample Size Calculations for studies Involving Linear Regression', Controlled Clinical Trials 1998; 19:589-601.
Changed:
<
<
Acknowledgement
>
>

Release Notes

Release Notes

Acknowledgements

 

This work was supported in part through a grant from Vanderbilt University's Clinical and Translational Science Award (CTSA) program (grant UL1 RR024975 from the NCRR/NIH).
Revision 37
Changes from r35 to r37
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"
Line: 23 to 23
 

To run the PS program after it has been installed, click the Start button, select Programs and then click PS. Click the Overview button for an introduction to the program and instruction on its use. PS is a self-documented program with extensive interactive help.
Changed:
<
<
We have had some luck running the program on the Linux (Ubuntu) operating system using Wine. You need at least version 1.1.10 of Wine for the program to run correctly and it runs a little better on each subsequent Wine release. Note that we don't guarantee anything if you try to run PS on Linux. It can be a little unstable sometimes, but we are using it successfully on a couple of Linux computers. To install Wine on a computer running Ubuntu Linux, use the command apt-get install wine. Then click on the icon above to download the PS installer (i.e. pssetup3.exe). Once pssetup3.exe is downloaded, click on it to begin the installation. The PS program uses the symbol font (symbol.ttf) to render Greek characters. You will need to obtain that font and install it so that the Greek characters will display correctly. As of version 9.10 of Ubuntu and Kubuntu there is a package available called "ttf-symbol-replacement" which is described as a "Free font with the same metrics as Symbol".
>
>
We have had some luck running the program on the Linux (Ubuntu) operating system using Wine. You need at least version 1.1.10 of Wine for the program to run correctly and it runs a little better on each subsequent Wine release. Note that we don't guarantee anything if you try to run PS on Linux. It can be a little unstable sometimes, but we are using it successfully on a couple of Linux computers. To install Wine on a computer running Ubuntu Linux, use the command sudo apt-get install wine. Then click on the icon above to download the PS installer (i.e. pssetup3.exe). Once pssetup3.exe is downloaded, click on it to begin the installation.

The PS program uses the symbol font (symbol.ttf) to render Greek characters. This seems to work correctly with versions of Ubuntu later than 9.10. If you use an earlier version, you will need to obtain that font and install it so that the Greek characters will display correctly. As of version 9.10 of Ubuntu and Kubuntu there is a package available called "ttf-symbol-replacement" which is described as a "Free font with the same metrics as Symbol".
 

We are interested in feedback. If you have any questions or comments about our software please send email to dale.plummer@vanderbilt.edu. It will be appreciated.
Line: 71 to 73
 
META FILEATTACHMENT attr="h" comment="" date="1107960561" name="ps_icon.jpg" path="ps_icon.jpg" size="654" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="Online documentation" date="1184257097" name="pshelp.chm" path="pshelp.chm" size="43439" user="DalePlummer" version="1.1"
META FILEATTACHMENT attachment="pssetup3.exe" attr="" comment="Power and Sample Size program version 3.0.43" date="1298065902" name="pssetup3.exe" path="pssetup3.exe" size="3379200" stream="IO::File=GLOB(0x95a0498)" tmpFilename="/tmp/TOGOL0Uric" user="DalePlummer" version="15"
Added:
>
>
META FILEATTACHMENT attachment="PS_icon.jpg" attr="" comment="" date="1314024289" name="PS_icon.jpg" path="PS_icon.jpg" size="912" stream="IO::File=GLOB(0x95ce6e4)" tmpFilename="/tmp/wTDniBFwro" user="DalePlummer" version="1"
META FILEATTACHMENT attachment="PS_icon.png" attr="" comment="" date="1314024311" name="PS_icon.png" path="PS_icon.png" size="1335" stream="IO::File=GLOB(0x8cf0768)" tmpFilename="/tmp/o91OGoCf3Q" user="DalePlummer" version="1"
META FILEATTACHMENT attachment="PS_icon.ico" attr="" comment="" date="1314024342" name="PS_icon.ico" path="PS_icon.ico" size="3262" stream="IO::File=GLOB(0x95dad50)" tmpFilename="/tmp/rmLFrPc2eY" user="DalePlummer" version="1"
Revision 35
Changes from r33 to r35
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"
Line: 65 to 65
 

We are grateful to Gordon R. Bernard for his support and to Yuwei Zhu for her assistance in editing this program.
Added:
>
>
Creative Commons License
PS: Power and Sample Size Calculation by William D. Dupont is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 United States License.
 

META FILEATTACHMENT attr="h" comment="" date="1107901832" name="ps_icon.ico" path="ps_icon.ico" size="766" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="" date="1107960561" name="ps_icon.jpg" path="ps_icon.jpg" size="654" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="Online documentation" date="1184257097" name="pshelp.chm" path="pshelp.chm" size="43439" user="DalePlummer" version="1.1"
Changed:
<
<
META FILEATTACHMENT attachment="pssetup3.exe" attr="" comment="" date="1297967747" name="pssetup3.exe" path="pssetup3.exe" size="3379200" stream="IO::File=GLOB(0x95a14a8)" tmpFilename="/tmp/jDPgmkYwql" user="DalePlummer" version="14"
>
>
META FILEATTACHMENT attachment="pssetup3.exe" attr="" comment="Power and Sample Size program version 3.0.43" date="1298065902" name="pssetup3.exe" path="pssetup3.exe" size="3379200" stream="IO::File=GLOB(0x95a0498)" tmpFilename="/tmp/TOGOL0Uric" user="DalePlummer" version="15"
Revision 33
Changes from r31 to r33
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"
Line: 69 to 69
 
META FILEATTACHMENT attr="h" comment="" date="1107901832" name="ps_icon.ico" path="ps_icon.ico" size="766" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="" date="1107960561" name="ps_icon.jpg" path="ps_icon.jpg" size="654" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="Online documentation" date="1184257097" name="pshelp.chm" path="pshelp.chm" size="43439" user="DalePlummer" version="1.1"
Changed:
<
<
META FILEATTACHMENT attachment="pssetup3.exe" attr="" comment="Power and Sample Size (PS version 3.0.17)" date="1284488016" name="pssetup3.exe" path="pssetup3.exe" size="3395584" stream="IO::File=GLOB(0x934e058)" tmpFilename="/tmp/Cxs5KoA9eY" user="DalePlummer" version="12"
>
>
META FILEATTACHMENT attachment="pssetup3.exe" attr="" comment="" date="1297967747" name="pssetup3.exe" path="pssetup3.exe" size="3379200" stream="IO::File=GLOB(0x95a14a8)" tmpFilename="/tmp/jDPgmkYwql" user="DalePlummer" version="14"
Revision 31
Changes from r29 to r31
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"
Line: 69 to 69
 
META FILEATTACHMENT attr="h" comment="" date="1107901832" name="ps_icon.ico" path="ps_icon.ico" size="766" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="" date="1107960561" name="ps_icon.jpg" path="ps_icon.jpg" size="654" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="Online documentation" date="1184257097" name="pshelp.chm" path="pshelp.chm" size="43439" user="DalePlummer" version="1.1"
Changed:
<
<
META FILEATTACHMENT attachment="pssetup3.exe" attr="" comment="Power and Sample Size (PS version 3.0.14)" date="1265734303" name="pssetup3.exe" path="pssetup3.exe" size="3395584" stream="IO::File=GLOB(0x9315118)" tmpFilename="/tmp/apreqQjz3x9" user="DalePlummer" version="11"
>
>
META FILEATTACHMENT attachment="pssetup3.exe" attr="" comment="Power and Sample Size (PS version 3.0.17)" date="1284488016" name="pssetup3.exe" path="pssetup3.exe" size="3395584" stream="IO::File=GLOB(0x934e058)" tmpFilename="/tmp/Cxs5KoA9eY" user="DalePlummer" version="12"
Revision 29
Changes from r27 to r29
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"
Line: 23 to 23
 

To run the PS program after it has been installed, click the Start button, select Programs and then click PS. Click the Overview button for an introduction to the program and instruction on its use. PS is a self-documented program with extensive interactive help.
Changed:
<
<
We have had some luck running the program on the Linux (Ubuntu) operating system using Wine. You need at least version 1.1.10 of Wine for the program to run correctly and it runs a little better on each subsequent Wine release. Note that we don't guarantee anything if you try to run PS on Linux. It can be a little unstable sometimes, but we are using it successfully on a couple of Linux computers. To install Wine on a computer running Ubuntu Linux, use the command apt-get install wine. Then click on the icon above to download the PS installer (i.e. pssetup3.exe). Once pssetup3.exe is downloaded, click on it to begin the installation. The PS program uses the symbol font (symbol.ttf) to render Greek characters. You will need to obtain that font and install it so that the Greek characters will display correctly.
>
>
We have had some luck running the program on the Linux (Ubuntu) operating system using Wine. You need at least version 1.1.10 of Wine for the program to run correctly and it runs a little better on each subsequent Wine release. Note that we don't guarantee anything if you try to run PS on Linux. It can be a little unstable sometimes, but we are using it successfully on a couple of Linux computers. To install Wine on a computer running Ubuntu Linux, use the command apt-get install wine. Then click on the icon above to download the PS installer (i.e. pssetup3.exe). Once pssetup3.exe is downloaded, click on it to begin the installation. The PS program uses the symbol font (symbol.ttf) to render Greek characters. You will need to obtain that font and install it so that the Greek characters will display correctly. As of version 9.10 of Ubuntu and Kubuntu there is a package available called "ttf-symbol-replacement" which is described as a "Free font with the same metrics as Symbol".
 

We are interested in feedback. If you have any questions or comments about our software please send email to dale.plummer@vanderbilt.edu. It will be appreciated.
Line: 69 to 69
 
META FILEATTACHMENT attr="h" comment="" date="1107901832" name="ps_icon.ico" path="ps_icon.ico" size="766" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="" date="1107960561" name="ps_icon.jpg" path="ps_icon.jpg" size="654" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="Online documentation" date="1184257097" name="pshelp.chm" path="pshelp.chm" size="43439" user="DalePlummer" version="1.1"
Changed:
<
<
META FILEATTACHMENT attachment="pssetup3.exe" attr="" comment="Power and Sample Size (PS version 3.0.12)" date="1249573814" name="pssetup3.exe" path="pssetup3.exe" size="3395584" stream="IO::File=GLOB(0x9201d9c)" tmpFilename="/tmp/apreqC4OBSs" user="DalePlummer" version="10"
>
>
META FILEATTACHMENT attachment="pssetup3.exe" attr="" comment="Power and Sample Size (PS version 3.0.14)" date="1265734303" name="pssetup3.exe" path="pssetup3.exe" size="3395584" stream="IO::File=GLOB(0x9315118)" tmpFilename="/tmp/apreqQjz3x9" user="DalePlummer" version="11"
Revision 27
Changes from r25 to r27
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"
Line: 9 to 9
 

by William D. Dupont and Walton D. Plummer, Jr.
Changed:
<
<
PS is an interactive program for performing power and sample size calculations. It can be used for studies with dichotomous, continuous, or survival response measures. The alternative hypothesis of interest may be specified either in terms of differing response rates, means, or survival times, or in terms of relative risks or odds ratios. Studies with dichotomous or continuous outcomes may involve either a matched or independent study design. The program can determine the sample size needed to detect a specified alternative hypothesis with the required power, the power with which a specific alternative hypothesis can be detected with a given sample size, or the specific alternative hypotheses that can be detected with a given power and sample size.
>
>
PS is an interactive program for performing power and sample size calculations that may be downloaded for free. It can be used for studies with dichotomous, continuous, or survival response measures. The alternative hypothesis of interest may be specified either in terms of differing response rates, means, or survival times, or in terms of relative risks or odds ratios. Studies with dichotomous or continuous outcomes may involve either a matched or independent study design. The program can determine the sample size needed to detect a specified alternative hypothesis with the required power, the power with which a specific alternative hypothesis can be detected with a given sample size, or the specific alternative hypotheses that can be detected with a given power and sample size.
 

The PS program can produce graphs to explore the relationships between power, sample size and detectable alternative hypotheses. It is often helpful to hold one of these variables constant and plot the other two against each other. The program can generate graphs of sample size versus power for a specific alternative hypothesis, sample size versus detectable alternative hypotheses for a specified power, or power versus detectable alternative hypotheses for a specified sample size. Linear or logarithmic axes may be used for either axes. Multiple curves can be plotted on a single graphic.
Line: 69 to 69
 
META FILEATTACHMENT attr="h" comment="" date="1107901832" name="ps_icon.ico" path="ps_icon.ico" size="766" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="" date="1107960561" name="ps_icon.jpg" path="ps_icon.jpg" size="654" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="Online documentation" date="1184257097" name="pshelp.chm" path="pshelp.chm" size="43439" user="DalePlummer" version="1.1"
Changed:
<
<
META FILEATTACHMENT attachment="pssetup3.exe" attr="" comment="Power and Sample Size (PS version 3.0.11)" date="1248457380" name="pssetup3.exe" path="pssetup3.exe" size="3395584" stream="IO::File=GLOB(0x90ce0b8)" tmpFilename="/tmp/apreqGOoJi0" user="DalePlummer" version="9"
>
>
META FILEATTACHMENT attachment="pssetup3.exe" attr="" comment="Power and Sample Size (PS version 3.0.12)" date="1249573814" name="pssetup3.exe" path="pssetup3.exe" size="3395584" stream="IO::File=GLOB(0x9201d9c)" tmpFilename="/tmp/apreqC4OBSs" user="DalePlummer" version="10"
Revision 25
Changes from r23 to r25
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"
Line: 69 to 69
 
META FILEATTACHMENT attr="h" comment="" date="1107901832" name="ps_icon.ico" path="ps_icon.ico" size="766" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="" date="1107960561" name="ps_icon.jpg" path="ps_icon.jpg" size="654" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="Online documentation" date="1184257097" name="pshelp.chm" path="pshelp.chm" size="43439" user="DalePlummer" version="1.1"
Changed:
<
<
META FILEATTACHMENT attachment="pssetup3.exe" attr="" comment="Power and Sample Size (PS version 3.0.8)" date="1244491579" name="pssetup3.exe" path="pssetup3.exe" size="3395584" stream="IO::File=GLOB(0x90b63fc)" tmpFilename="/tmp/apreqcfM6hP" user="DalePlummer" version="6"
>
>
META FILEATTACHMENT attachment="pssetup3.exe" attr="" comment="Power and Sample Size (PS version 3.0.11)" date="1248457380" name="pssetup3.exe" path="pssetup3.exe" size="3395584" stream="IO::File=GLOB(0x90ce0b8)" tmpFilename="/tmp/apreqGOoJi0" user="DalePlummer" version="9"
Revision 23
Changes from r21 to r23
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"
Line: 19 to 19
 

The program runs on the Microsoft Windows operating systems ( Windows 2000 and later).
Added:
>
>
Caution: As of 08 Jun 2009 we know of a bug in one of the third-party tools that we use that causes the program to malfunction when the Windows language is set to something other than English. We are working to replace this tool with one of our own and we apologize for any inconvenience that this problem causes.
  To run the PS program after it has been installed, click the Start button, select Programs and then click PS. Click the Overview button for an introduction to the program and instruction on its use. PS is a self-documented program with extensive interactive help.

We have had some luck running the program on the Linux (Ubuntu) operating system using Wine. You need at least version 1.1.10 of Wine for the program to run correctly and it runs a little better on each subsequent Wine release. Note that we don't guarantee anything if you try to run PS on Linux. It can be a little unstable sometimes, but we are using it successfully on a couple of Linux computers. To install Wine on a computer running Ubuntu Linux, use the command apt-get install wine. Then click on the icon above to download the PS installer (i.e. pssetup3.exe). Once pssetup3.exe is downloaded, click on it to begin the installation. The PS program uses the symbol font (symbol.ttf) to render Greek characters. You will need to obtain that font and install it so that the Greek characters will display correctly.
Line: 66 to 69
 
META FILEATTACHMENT attr="h" comment="" date="1107901832" name="ps_icon.ico" path="ps_icon.ico" size="766" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="" date="1107960561" name="ps_icon.jpg" path="ps_icon.jpg" size="654" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="Online documentation" date="1184257097" name="pshelp.chm" path="pshelp.chm" size="43439" user="DalePlummer" version="1.1"
Changed:
<
<
META FILEATTACHMENT attachment="pssetup3.exe" attr="" comment="Power and Sample Size (PS version 3.0.4)" date="1242136190" name="pssetup3.exe" path="pssetup3.exe" size="3395584" stream="IO::File=GLOB(0x9660c54)" tmpFilename="/tmp/apreqSIAwQo" user="DalePlummer" version="4"
>
>
META FILEATTACHMENT attachment="pssetup3.exe" attr="" comment="Power and Sample Size (PS version 3.0.8)" date="1244491579" name="pssetup3.exe" path="pssetup3.exe" size="3395584" stream="IO::File=GLOB(0x90b63fc)" tmpFilename="/tmp/apreqcfM6hP" user="DalePlummer" version="6"
Revision 21
Changes from r19 to r21
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"
Changed:
<
<
>
>
 

PS: Power and Sample Size Calculation

Changed:
<
<
PS: Power and Sample Size Calculation ps_icon.jpg Get PS (3.3 MB) version 3.0, 2009
>
>
PS: Power and Sample Size Calculation ps_icon.jpg Get PS (3.3 MB) version 3.0, 2009
 

Release Notes
Line: 36 to 27
 

Study Designs That Can Be Evaluated By This Program
Changed:
<
<
  1. Case-Control Studies -- Corrected and uncorrected chi-squared contingency table tests, Fisher’s exact-test: The method of Schlesselman (1982) is used for studies with independent case and control groups that will be analyzed using an uncorrected chi-squared test; the method of Casagrande et al. (1978) is used for independent studies that will be analyzed using continuity corrected chi-squared statistics or Fisher’s exact-test. When the case and control sample sizes are unequal, PS uses the generalization of Casagrande’s method proposed by Fleiss (1981). The alternative hypotheses may be specified in terms of odds ratios or exposure prevalence rates.
  2. Matched Case-Control Studies -- McNemar’s Test: The method of Dupont (1988) is used for studies with paired or matched cases and controls. The alternative hypotheses are specified in terms of odds ratios.
>
>
  1. Case-Control Studies -- Corrected and uncorrected chi-squared contingency table tests, Fisher’s exact-test: The method of Schlesselman (1982) is used for studies with independent case and control groups that will be analyzed using an uncorrected chi-squared test; the method of Casagrande et al. (1978) is used for independent studies that will be analyzed using continuity corrected chi-squared statistics or Fisher’s exact-test. When the case and control sample sizes are unequal, PS uses the generalization of Casagrande’s method proposed by Fleiss (1981). The alternative hypotheses may be specified in terms of odds ratios or exposure prevalence rates.
  2. Matched Case-Control Studies -- McNemar’s Test: The method of Dupont (1988) is used for studies with paired or matched cases and controls. The alternative hypotheses are specified in terms of odds ratios.
 
  1. Multiple 2 X 2 tables -- Mantel-Haenszel Test: The method of Wittes and Wallenstein (1987) is used. Assume that each 2 X 2 table consists of cases and controls selected from a different stratum that is defined by one or more confounding variables. The odds ratio for disease in exposed subjects compared to unexposed subjects is assumed to be equal within all strata. The alternative hypotheses are specified in terms of this odds ratio.
Changed:
<
<
  1. Cohort Studies With Dichotomous Outcomes -- Independent contingency table tests, McNemar’s test: The methods of Schlesselman (1982), Casagrande et al. (1978), Fleiss (1981), and Dupont (1988) are available. The alternative hypotheses may be specified in terms of relative risks or outcome probabilities.
>
>
  1. Cohort Studies With Dichotomous Outcomes -- Independent contingency table tests, McNemar’s test: The methods of Schlesselman (1982), Casagrande et al. (1978), Fleiss (1981), and Dupont (1988) are available. The alternative hypotheses may be specified in terms of relative risks or outcome probabilities.
 
  1. Linear Regression (1 Treatment) -- Testing the slope of a simple linear regression line: The method of Dupont and Plummer (1998) is used to design studies in which we wish to detect a regression slope of a given magnitude. The values of the independent (x) variable of the regression line may either be specified by the investigator or determined observationally when the study is performed. In the latter case, the investigator must estimate the standard deviation of the independent variable(s).
  2. Linear Regression (2 Treatments) -- Comparing the slopes and intercepts of two independent linear regressions: The approach of Dupont and Plummer (1998) is used to design studies in which we wish to determine whether the slopes or intercepts of two independent regression lines differ by a given amount. The values of the independent (x) variables of the regression lines may either be specified by the investigator or determined observationally when the study is performed. In the latter case, the investigator must estimate the standard deviations of the independent variables.
  3. Survival Studies -- Evaluating independent cohorts using the log-rank test: The approach of Schoenfeld and Richter (1982) is used. The ratio of the number of control subjects per experimental subject in the cohorts being compared may be specified by the user. The alternative hypotheses are specified in terms of the hazard ratio for control subjects relative to experimental subjects or the median survival times for control and experimental subjects.
Line: 58 to 49
 
  1. Visual Components Sybase Inc. First Impression Active X User's Guide: High Performance Software for Charting Data for Microsoft Visual Basic, Visual C++, and Other Languages. Version 5.0. Overland Park, KS: Visual Components Sybase Inc.
  2. Mantel, N., & Haenszel, W. (1959) Statistical aspects of the analysis of data from retrospective studies of disease. Journal of the National Cancer Institute, 22, 719-748.
  3. Dupont, WD (2008). Statistical Modeling for Biomedical Researchers, 2nd Edition. Cambridge, U.K.: Cambridge University Press.
Added:
>
>
Suggested citation

Dupont WD, Plummer WD: 'Power and Sample Size Calculations: A Review and Computer Program', Controlled Clinical Trials 1990; 11:116-28.

or

Dupont WD, Plummer WD: 'Power and Sample Size Calculations for studies Involving Linear Regression', Controlled Clinical Trials 1998; 19:589-601.
 

Acknowledgement
Line: 68 to 66
 
META FILEATTACHMENT attr="h" comment="" date="1107901832" name="ps_icon.ico" path="ps_icon.ico" size="766" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="" date="1107960561" name="ps_icon.jpg" path="ps_icon.jpg" size="654" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="Online documentation" date="1184257097" name="pshelp.chm" path="pshelp.chm" size="43439" user="DalePlummer" version="1.1"
Changed:
<
<
META FILEATTACHMENT attr="" comment="Power and Sample Size (PS version 3.0.2)" date="1233247453" name="pssetup3.exe" path="pssetup3.exe" size="3395584" user="DalePlummer" version="1.3"
>
>
META FILEATTACHMENT attachment="pssetup3.exe" attr="" comment="Power and Sample Size (PS version 3.0.4)" date="1242136190" name="pssetup3.exe" path="pssetup3.exe" size="3395584" stream="IO::File=GLOB(0x9660c54)" tmpFilename="/tmp/apreqSIAwQo" user="DalePlummer" version="4"
Revision 19
Changes from r17 to r19
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"

PS: Power and Sample Size Calculation

Changed:
<
<
PS Power and Sample Size Calculation
>
>
PS: Power and Sample Size Calculation
  ps_icon.jpg Get PS (3.3 MB) version 3.0, 2009

Release Notes
Line: 22 to 22
 

The PS program can produce graphs to explore the relationships between power, sample size and detectable alternative hypotheses. It is often helpful to hold one of these variables constant and plot the other two against each other. The program can generate graphs of sample size versus power for a specific alternative hypothesis, sample size versus detectable alternative hypotheses for a specified power, or power versus detectable alternative hypotheses for a specified sample size. Linear or logarithmic axes may be used for either axes. Multiple curves can be plotted on a single graphic.
Changed:
<
<
Downloading the Software
>
>
Downloading and Installing the Software
 

The PS program is freely available on the Internet. To obtain this software on your computer click PS (3.3 MB). Instruct your browser to download the file to a folder on your computer. A file called pssetup3.exe will be downloaded to this location. Run pssetup3.exe to extract the needed files and install the program.
Changed:
<
<
The program runs on the Microsoft Windows operating systems (Windows 2000 and later).
>
>
The program runs on the Microsoft Windows operating systems (Windows 2000 and later).
 

To run the PS program after it has been installed, click the Start button, select Programs and then click PS. Click the Overview button for an introduction to the program and instruction on its use. PS is a self-documented program with extensive interactive help.
Added:
>
>
We have had some luck running the program on the Linux (Ubuntu) operating system using Wine. You need at least version 1.1.10 of Wine for the program to run correctly and it runs a little better on each subsequent Wine release. Note that we don't guarantee anything if you try to run PS on Linux. It can be a little unstable sometimes, but we are using it successfully on a couple of Linux computers. To install Wine on a computer running Ubuntu Linux, use the command apt-get install wine. Then click on the icon above to download the PS installer (i.e. pssetup3.exe). Once pssetup3.exe is downloaded, click on it to begin the installation. The PS program uses the symbol font (symbol.ttf) to render Greek characters. You will need to obtain that font and install it so that the Greek characters will display correctly.
  We are interested in feedback. If you have any questions or comments about our software please send email to dale.plummer@vanderbilt.edu. It will be appreciated.

Study Designs That Can Be Evaluated By This Program
Line: 59 to 61
 

Acknowledgement
Changed:
<
<
This work was supported in part through a grant from Vanderbilt University's Clinical and Translational Science Award (CTSA) program.
>
>
This work was supported in part through a grant from Vanderbilt University's Clinical and Translational Science Award (CTSA) program (grant UL1 RR024975 from the NCRR/NIH).
 

We are grateful to Gordon R. Bernard for his support and to Yuwei Zhu for her assistance in editing this program.
Deleted:
<
<
META FILEATTACHMENT attr="" comment="Power and Sample Size (previous version)" date="1080592040" name="pssetup.exe" path="C:\Documents and Settings\plummer\My Documents\pssetup.exe" size="5351424" user="DalePlummer" version="1.1"
 
META FILEATTACHMENT attr="h" comment="" date="1107901832" name="ps_icon.ico" path="ps_icon.ico" size="766" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="" date="1107960561" name="ps_icon.jpg" path="ps_icon.jpg" size="654" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="Online documentation" date="1184257097" name="pshelp.chm" path="pshelp.chm" size="43439" user="DalePlummer" version="1.1"
Changed:
<
<
META FILEATTACHMENT attr="" comment="Power and Sample Size (current version)" date="1231446731" name="pssetup3.exe" path="pssetup3.exe" size="3395584" user="DalePlummer" version="1.2"
>
>
META FILEATTACHMENT attr="" comment="Power and Sample Size (PS version 3.0.2)" date="1233247453" name="pssetup3.exe" path="pssetup3.exe" size="3395584" user="DalePlummer" version="1.3"
Revision 17
Changes from r15 to r17
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"
 

PS: Power and Sample Size Calculation

PS Power and Sample Size Calculation ps_icon.jpg Get PS (5.2 MB) version 2.1.31, 2004
Line: 42 to 51
 
  1. Fleiss JL: Statistical Methods for Rates and Proportions. 2nd Ed. New York: John Wiley & Sons, 1981
  2. Dupont WD: Power calculations for matched case-control studies. Biometrics 44:1157-1168, 1988
Deleted:
<
<
 

META FILEATTACHMENT attr="h" comment="Power and Sample Size" date="1080592040" name="pssetup.exe" path="C:\Documents and Settings\plummer\My Documents\pssetup.exe" size="5351424" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="" date="1107901832" name="ps_icon.ico" path="ps_icon.ico" size="766" user="DalePlummer" version="1.1"
Revision 11
Changes from r9 to r11
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"

PS: Power and Sample Size Calculation

PS Power and Sample Size Calculation
Line: 9 to 9
 

by William D. Dupont and Walton D. Plummer, Jr.
Changed:
<
<
PS is an interactive program for performing power and sample size calculations. The program runs on the Microsoft Windows operating systems (Windows 95 and later). It can be used for studies with dichotomous, continuous, or survival response measures. The alternative hypothesis of interest may be specified either in terms of differing response rates, means, or survival times, or in terms of relative risks or odds ratios. Studies with dichotomous or continuous outcomes may involve either a matched or independent study design. The program can determine the sample size needed to detect a specified alternative hypothesis with the required power, the power with which a specific alternative hypothesis can be detected with a given sample size, or the specific alternative hypotheses that can be detected with a given power and sample size.
>
>
PS is an interactive program for performing power and sample size calculations. It can be used for studies with dichotomous, continuous, or survival response measures. The alternative hypothesis of interest may be specified either in terms of differing response rates, means, or survival times, or in terms of relative risks or odds ratios. Studies with dichotomous or continuous outcomes may involve either a matched or independent study design. The program can determine the sample size needed to detect a specified alternative hypothesis with the required power, the power with which a specific alternative hypothesis can be detected with a given sample size, or the specific alternative hypotheses that can be detected with a given power and sample size.
 

The PS program can produce graphs to explore the relationships between power, sample size and detectable alternative hypotheses. It is often helpful to hold one of these variables constant and plot the other two against each other. The program can generate graphs of sample size versus power for a specific alternative hypothesis, sample size versus detectable alternative hypotheses for a specified power, or power versus detectable alternative hypotheses for a specified sample size. Linear or logarithmic axes may be used for either axes. Multiple curves can be plotted on a single graphic.
Line: 17 to 17
 

The PS program is freely available on the Internet. To obtain this software on your computer click PS (5.2 MB). Instruct your browser to download the file to a folder on your computer. A file called pssetup.exe will be downloaded to this location. Run pssetup.exe to extract the needed files and install the program.
Added:
>
>
The program runs on the Microsoft Windows operating systems (Windows 95 and later). We have not tested the PS program with Microsoft Vista, though we have had a few reports that it does work. Sometimes, the help functionality does not work under Vista. There is some additional software that can be downloaded from Microsoft that will help. See http://support.microsoft.com/kb/917607 for details.
  To run the PS program after it has been installed, click the Start button, select Programs and then click PS. Click the Overview button for an introduction to the program and instruction on its use. PS is a self-documented program with extensive interactive help.

We are interested in feedback. If you have any questions or comments about our software please send email to dale.plummer@vanderbilt.edu. It will be appreciated.
Line: 40 to 42
 
  1. Fleiss JL: Statistical Methods for Rates and Proportions. 2nd Ed. New York: John Wiley & Sons, 1981
  2. Dupont WD: Power calculations for matched case-control studies. Biometrics 44:1157-1168, 1988
Added:
>
>
 
META FILEATTACHMENT attr="h" comment="Power and Sample Size" date="1080592040" name="pssetup.exe" path="C:\Documents and Settings\plummer\My Documents\pssetup.exe" size="5351424" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="" date="1107901832" name="ps_icon.ico" path="ps_icon.ico" size="766" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="" date="1107960561" name="ps_icon.jpg" path="ps_icon.jpg" size="654" user="DalePlummer" version="1.1"
Added:
>
>
META FILEATTACHMENT attr="h" comment="Online documentation" date="1184257097" name="pshelp.chm" path="pshelp.chm" size="43439" user="DalePlummer" version="1.1"
Revision 9
Changes from r7 to r9
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"

PS: Power and Sample Size Calculation

PS Power and Sample Size Calculation
Changed:
<
<
ps_icon.jpg Get PS (3.5 MB) version 2.1.51, June, 2005
>
>
ps_icon.jpg Get PS (5.2 MB) version 2.1.31, 2004
 

Release Notes
Revision 7
Changes from r5 to r7
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"
Changed:
<
<

PS: Power and Sample Size

ps_icon.jpg Get PS (5.2 MB) version 2.1.31, October, 2003
>
>

PS: Power and Sample Size Calculation

PS Power and Sample Size Calculation ps_icon.jpg Get PS (3.5 MB) version 2.1.51, June, 2005
 

Release Notes
Revision 5
Changes from r3 to r5
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"

PS: Power and Sample Size

Changed:
<
<
Get PS (5.2 MB) version 2.1.31, October, 2003
>
>
ps_icon.jpg Get PS (5.2 MB) version 2.1.31, October, 2003
 

Release Notes
Line: 15 to 15
 

Downloading the Software
Changed:
<
<
The PS program is freely available on the Internet. To obtain this software on your computer click PS (5.2 MB). Instruct your browser to download the file to a folder on your computer. A file called PSsetup.exe will be downloaded to this location. Run PSsetup.exe to extract the needed files and install the program.
>
>
The PS program is freely available on the Internet. To obtain this software on your computer click PS (5.2 MB). Instruct your browser to download the file to a folder on your computer. A file called pssetup.exe will be downloaded to this location. Run pssetup.exe to extract the needed files and install the program.
 

To run the PS program after it has been installed, click the Start button, select Programs and then click PS. Click the Overview button for an introduction to the program and instruction on its use. PS is a self-documented program with extensive interactive help.
Line: 41 to 41
 
  1. Dupont WD: Power calculations for matched case-control studies. Biometrics 44:1157-1168, 1988

META FILEATTACHMENT attr="h" comment="Power and Sample Size" date="1080592040" name="pssetup.exe" path="C:\Documents and Settings\plummer\My Documents\pssetup.exe" size="5351424" user="DalePlummer" version="1.1"
Added:
>
>
META FILEATTACHMENT attr="h" comment="" date="1107901832" name="ps_icon.ico" path="ps_icon.ico" size="766" user="DalePlummer" version="1.1"
META FILEATTACHMENT attr="h" comment="" date="1107960561" name="ps_icon.jpg" path="ps_icon.jpg" size="654" user="DalePlummer" version="1.1"
Revision 3
Changes from r1 to r3
Line: 1 to 1
 
META TOPICPARENT name="DalePlummer"

PS: Power and Sample Size

Line: 7 to 7
  Release Notes
Changed:
<
<
by William D. Dupont and Walton D. Plummer, Jr.
>
>
by William D. Dupont and Walton D. Plummer, Jr.
 

PS is an interactive program for performing power and sample size calculations. The program runs on the Microsoft Windows operating systems (Windows 95 and later). It can be used for studies with dichotomous, continuous, or survival response measures. The alternative hypothesis of interest may be specified either in terms of differing response rates, means, or survival times, or in terms of relative risks or odds ratios. Studies with dichotomous or continuous outcomes may involve either a matched or independent study design. The program can determine the sample size needed to detect a specified alternative hypothesis with the required power, the power with which a specific alternative hypothesis can be detected with a given sample size, or the specific alternative hypotheses that can be detected with a given power and sample size.
Line: 15 to 15
 

Downloading the Software
Changed:
<
<
The PS program is freely available on the Internet. To obtain this software on your computer click PS (5.2 MB). Instruct your browser to download the file to a folder on your computer. A file called PSsetup.exe will be downloaded to this location. Run PSsetup.exe to extract the needed files and install the program.
>
>
The PS program is freely available on the Internet. To obtain this software on your computer click PS (5.2 MB). Instruct your browser to download the file to a folder on your computer. A file called PSsetup.exe will be downloaded to this location. Run PSsetup.exe to extract the needed files and install the program.
 

To run the PS program after it has been installed, click the Start button, select Programs and then click PS. Click the Overview button for an introduction to the program and instruction on its use. PS is a self-documented program with extensive interactive help.
Line: 23 to 23
 

Study Designs That Can Be Evaluated By This Program
Changed:
<
<
  1. Survival Studies: Evaluation of independent cohorts using the log-rank test. The approach of Schoenfeld and Richter3 is used. The ratio of number of patients in the cohorts being compared may be specified by the user.
  2. Continuous Response Measures in Two Groups: Paired and independent t tests. The approach of Dupont and Plummer1 is used for paired and independent samples. The ratio of number of patients in the samples being compared may be specified by the user. This method produces results that are in close agreement with those of Pearson and Hartley.4
  3. Linear Regression: Tests of slopes, comparisons of slopes and intercepts from independent regressions. The methods of Dupont and Plummer2 is used. They may be used to design studies in which we wish to detect a regression slope of a given magnitude. They may also be used when we wish to determine whether the slopes or intercepts of two independent regression lines differ by a given amount. The values of the independent (x) variable(s) of the regression line(s) may either be specified by the investigator or determined observationally when the study is performed. In the latter case, the investigator must estimate the standard deviation(s) of the independent variable(s).
  4. Independent Case-Control Studies: Corrected and uncorrected c2 contingency table tests, Fisher's exact test. The method of Schlesselman5 is used for studies with independent case and control groups that will be analyzed using an uncorrected c2 test; the method of Casagrande et al.6 is used for independent studies that will be analyzed using continuity corrected c2 statistics or Fisher's exact test. When the case and control sample sizes are unequal, PS uses the generalization of Casagrande's method proposed by Fleiss.7 The alternative hypotheses may be specified in terms of odds ratios or exposure prevalence rates.
  5. Matched Case-Control Studies: McNemar's Test. The method of Dupont8 is used for studies with paired or matched cases and controls. The alternative hypotheses may be specified in terms of odds ratios or exposure prevalence rates.
  6. Cohort Studies With Dichotomous Outcomes: Independent contingency table tests, McNemar's test. The methods of Schlesselman,5 Casagrande,6 Fleiss7 and Dupont8 are available. The alternative hypotheses may be specified in terms of relative risks or outcome probabilities.
>
>
  1. Survival Studies: Evaluation of independent cohorts using the log-rank test. The approach of Schoenfeld and Richter3 is used. The ratio of number of patients in the cohorts being compared may be specified by the user.
  2. Continuous Response Measures in Two Groups: Paired and independent t tests. The approach of Dupont and Plummer1 is used for paired and independent samples. The ratio of number of patients in the samples being compared may be specified by the user. This method produces results that are in close agreement with those of Pearson and Hartley.4
  3. Linear Regression: Tests of slopes, comparisons of slopes and intercepts from independent regressions. The methods of Dupont and Plummer2 is used. They may be used to design studies in which we wish to detect a regression slope of a given magnitude. They may also be used when we wish to determine whether the slopes or intercepts of two independent regression lines differ by a given amount. The values of the independent (x) variable(s) of the regression line(s) may either be specified by the investigator or determined observationally when the study is performed. In the latter case, the investigator must estimate the standard deviation(s) of the independent variable(s).
  4. Independent Case-Control Studies: Corrected and uncorrected chi-square contingency table tests, Fisher's exact test. The method of Schlesselman5 is used for studies with independent case and control groups that will be analyzed using an uncorrected chi-square test; the method of Casagrande et al.6 is used for independent studies that will be analyzed using continuity corrected chi-square statistics or Fisher's exact test. When the case and control sample sizes are unequal, PS uses the generalization of Casagrande's method proposed by Fleiss.7 The alternative hypotheses may be specified in terms of odds ratios or exposure prevalence rates.
  5. Matched Case-Control Studies: McNemar's Test. The method of Dupont8 is used for studies with paired or matched cases and controls. The alternative hypotheses may be specified in terms of odds ratios or exposure prevalence rates.
  6. Cohort Studies With Dichotomous Outcomes: Independent contingency table tests, McNemar's test. The methods of Schlesselman,5 Casagrande,6 Fleiss7 and Dupont8 are available. The alternative hypotheses may be specified in terms of relative risks or outcome probabilities.
 

References
  1. Dupont WD, Plummer WD, Jr: Power and Sample Size Calculations: A Review and Computer Program. Controlled Clinical Trials 11:116-128, 1990
 
This site is powered by FoswikiCopyright © 2013-2017 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding Vanderbilt Biostatistics Wiki? Send feedback