The Epi Info™ Story

The beginning of flexible computing in public health.

Auditorium A at CDC, converted to a war room for the Swine Flu crisis, is filled with epidemiologists and a Digital Equipment PDP 11 minicomputer the size of a refrigerator.

A program called SOCRATES, written in FORTRAN by programmer Rick Curtis, allowed an epidemiologist to define questions, enter data, and summarize the results in tabular form without the aid of a programmer.

Jeffrey A. Dean, a Junior at Paidea High School, began a field internship in computing at an insurance company, which required keeping a large printer supplied with paper. He expressed a desire for a more challenging experience to his Dad, who gave him specifications for a data entry program for epidemiology.

During March 1985, he wrote ENTER in Turbo Pascal, the language he had previously used to adapt a mainframe version of Dungeons and Dragons to a microcomputer.

Tony Burton, author of the BASIC version of the Epidemiologic Analysis System, provided ideas for the first version of ANALYSIS, programmed by Jeff during the summer of 1986.

Several years later, Tony moved to the Global Programme on AIDS, World Health Organization, Geneva, and he and Jeff continued to collaborate on later versions of Epi Info™ as Jeff traveled to Geneva during college vacations.

Dr. Richard Dicker, author of the Epidemiology in Action training manual and coordinator of the Epidemic Intelligence Service (EIS) course at CDC, provided advice on the statistics that were included with Epi Info™.

A 27-page manual was added in February 1986, and the “Programs for Automatic File Definition, Data Entry, and Tabulation” were now called Epi Info™.

Distribution was informal; anyone who wanted the programs was given a photocopy of the manual and a 5 1/4 inch floppy diskette.

Epi Info™, Version 2, had a bound manual of 112 pages, a pull down menu, the EPED word processor for creating questionnaires, ENTER, ANALYSIS, an epidemiologic calculator called STATCALC, EPICURVE for plotting histograms, a MERGE program, and IMPORT and CONVERT programs for file conversions.

The TABLES command began to offer statistical output. Note the negative chi square, probably a result of limitations in integer values in an early version of Turbo Pascal.

The first versions of Epi Info™ were distributed by Andy, Jeff, and Tony from their office.

Suggestions came from users in the field and were rapidly incorporated into new versions of the software.

CDC and WHO Collaboration

WHO, Geneva	CDC, Atlanta

Epi Info™, Version 4, was developed by Tony Burton, who had moved to the World Health Organization, Geneva, and by Jeff Dean, who worked there during summer vacations.

It had greatly enhanced features, but also a number

of bugs, and was used as the basis for Version 5, released from CDC.

Chris Smith	Karl Brendel	Tom Arner

Epi Map, Version 1, was developed by Jeff Dean and Tony Burton in Geneva, with debugging and enhancements by Karl Brendel at CDC. Version 2, developed at CDC, added features for programming what happens after mouse clicks on geographic areas.

Dr. Denis Coulombier contributed two new programs, EpiTable and EpiNut, for statistical processing of tables and nutritional anthropometry, and many programming examples to Version 6. This version and several minor upgrades provided a solid basis for individual public health computing through the decade of the 90’s and for worldwide distribution.

Graphs of nutritional values of a population compared with an international reference population in Nutstat.

A conference on “Microcomputers and the Future of Epidemiology” convened 130 public health experts in Atlanta and provided the basis for designing a Windows version of Epi Info™.

Dr. Andy Dean on the left poses with translators of Epi Info™ into Spanish (Juan Carlos Fernández Merino), Chinese, French (Dr. Robert Freund), Indonesian (Dr. Pandu Riono), and Arabic (Dr. Samy Sidki).

Internet distribution of Epi Info™ began, making it available to a wide international audience without charge.

“It is a generally accepted rule in the software business that producing a working prototype is only 20% of the cost of making a commercial product.“(from a report of the Working Group on Biomedical Computing, Advisory Committee to the Director, National Institutes of Health, June 3, 1999).

Much of the work in making Epi Info™ useful on a range of computers worldwide in the hands of many different kinds of users is in debugging, testing, documenting, obtaining user feedback, and providing technical support to users.

An important feature in Epi Info’s™ acceptance is the Epi Info™ Hotline. Two Hotline staff members respond to 20 to 40 inquiries per day by telephone, FAX, and e-mail. The Hotline not only provides support and builds confidence among users, but also is a channel through which problems and suggestions become available to the development team.

During the Summer of 1997, an evaluation of Epi Info™ distribution was performed by Braddee Harbage, a student intern, using e-mail and the Internet to contact as many distributors of Epi Info™ as possible. Results included:

• A minimum estimate of 145,320 copies of Epi Info™ and Epi Map distributed in more than 117 countries
• 1207 citations in the scientific literature
• 52 Internet sites providing copies of the Epi Info™ programs, manual, or related materials
• An estimate that 66% of copies were distributed by Internet

for Microsoft Windows 95/98/NT

The Epi Info™ 2000 Development Team: Tom Arner, Karl Brendel, Andy Dean, Sireesha Sangam, and Godha Sunki.

Fast processors disclosed a bug in the original Turbo Pascal software. The programs were recompiled with a patched version, and are now available as Version 6.04d, consolidated on 3 diskettes. It is important to download and install the new version for use on any machine with modern processing speeds (more than about 400 mhz).

Before 1980, a few epidemiologists used mainframe computers or struggled to assemble, program, and use microcomputers.

Minicomputer software allowed CDC epidemiologists to develop questionnaires and analyze data through terminals.

In the 80s, microcomputers and local area networks became standard public health tools.

Epi Info™ and other database and statistics programs became standard equipment for public health. Epi Info™ was used for surveillance systems, disease investigations, surveys, clinical research, nutritional anthropometry, and veterinary and dental public health.

Translations of the programs or manual appeared in 13 non-English languages.

Worldwide copies exceeded 145,000 in 117 countries.

Epi Info™ 2000 for Windows 95, 98, and NT will bring the benefits of hands-on questionnaire creation, database management, statistics, mapping and graphing to Windows, with Internet enhancements to follow.