WINPEPI (PEPI-for-Windows)

Joe Abramson has developed an augmented Windows version (WINPEPI) of the PEPI suite of programs for epidemiologists. You can read a description of WINPEPI (published in Epidemiologic Perspectives & Innovations) by clicking  A list of currently available functions and procedures is available here.

The latest update (version 11.44) was posted to this site on January 24, 2015..

Download the latest version of WINPEPI as an executable (.EXE) file (5.8 mb).

The downloaded file will be WinPepiSetup.exe. Alternatively, you can download it in a ZIP archive :

Download the latest version of WINPEPI as a .ZIP archive (5.8 mb)

which you will have to open to access WinPepiSetup.exe.

When you run WinPepiSetup.exe, it will install the latest WINPEPI programs and manuals, and an index to the statistical procedures and programs, in any folder you select. Older versions will be replaced. Follow the instructions, and your desktop will have a portal to the programs and manuals, the index, and relevant Internet sites.  No changes are made to the Windows registry.

As a third alternative,  if you do not have permission to use an installation program (but can download executable files in a zip file), download, which contains all the components of WINPEPI, but no installation program. You will have to open this zip file and copy its contents to a directory of your choice (overwriting any previous versions), and manually put a shortcut to winpepi.exe (the portal program) on your desktop.

           Download the WINPEPI files in a ZIP archive (without an installation program)  (7.5 mb).

All the programs are 32-bit applications, and will run in any version of Microsoft Windows except Windows 3.

A report from the McAfee Site Advisor confirms that "This link is safe. We tested it and didn't find any significant security issues”..



Kaplan-Meier and risk-difference curves for comparison of survival data (e.g. in a clinical trial).

Sample size for estimation of intraclass correlation coefficient.

Pseudo-Bayesian confidence intervals for difference between proportions



Confidence intervals for differences between sensitivities, specificities, and false positive rates.

Wilson-score confidence intervals for odds ratio.

Improved Wald method (LaPlace adjustment) confidence intervals for difference between proportions (pared data)

ED50/ED90 by probit analysis , the median effective or lethal dose

ED90/LD90 by probit analysis (the effective/or  lethal dose in 90% of subjects)

Propensity-score analysis.

Lang-Reiczigel procedure for estimating C.I. of disease prevalence from screening test results.

Hodges-Lehmann procedure for estimating median of differences between (e.g.) cases and multiple matched controls.

Critical Prior Interval procedure for Bayesian appraisal of an association.

Cohen's f-squared effect size measure.

Sidak-adjuted P-values for multiple tests.

Separate results (in meta-analysis) for different categories of studies.

Comparison of two odds ratios or other ratio measures.

Block randomization with randomly selected block sizes.

Viechtabuer's C.I.s for standardized mean differences (effect sizes).

Killeen's P(rep) (probability of replication) for comparisons of independent and paired proportions and means.

Calculation of confidence interval from P value, and vice versa.

Use of odds ratio in appraisal of screening/diagnostic tests.

Odds ratio based on incompletely paired data;

Intraclass kappa;

Weighted kappa for two ratings of a "yes-no" variable;

One-way ANOVA based on means and SDs;

Overall measure of disagreement for more than two observers;


To avoid problems with administrator rights in recent versions of Windows, all results are now automatically saved in PEPI.TXT in the Winpepi folder, instead of in C:\PEPI.TXT, where older results may be found.

The currently available WINPEPI programs are :

COMPARE2.EXE - For comparisons of two independent groups or samples. The current version number is 3.46.

DESCRIBE.EXE - For use in descriptive epidemiology including the appraisal of separate samples in comparative studies. The current version number is 2.72.

ETCETERA.EXE - Miscellaneous (randomization, random sampling, adjustment of multiple-test p-values, appraisal of synergism, assessment of a scale, correlation-coefficient tools, large contingency tables, three-way tables, median polish and mean polish, appraisal of effect of unmeasured confounders). The current version number is 2.97.

LOGISTIC.EXE - Multiple logistic regression. The current version number is 1.53.

PAIRSetc.EXE - For appraisal of differences and agreement between matched samples or observations. The current version number is 3.45.

POISSON.EXE - Multiple Poisson regression. The current version number is 1.26.

WHATIS.EXE - An expression evaluator (with storage of constants, interim results, and formulae) and calculator for p values (and their inverse), confidence intervals, and time spans. The current version number is 4.59.

Manuals are supplied in PDF format, which can be read with (e.g.) Foxit Reader or the Adobe Acrobat Reader.

For a paper describing the programs, see  Abramson,J.H. WINPEPI updated: computer programs for epidemiologists, and their teaching potential. Epidemiologic Perspectives & Innovations 2011, 8:1 (can be accessed via the WinPepi portal, and is available on the Internet at  The programs and their uses are also described in Encyclopedia of Research Design (ed. N.J. Salkind), vol. 3, Sage Publications, 2010, 1633-1636.  A description was also published in the Epidemiology Monitor 2007 28(Oct.): 1-7, with an update in the March 2009 issue. There is a brief and usually out-of-date description in Wikipedia.

Please report any problems you experience or any suggestions you may have to improve the package. E-mail your comments &c.