Making Life Easy Using Epi Info:An Introduction

Ali Rowhani-Rahbar, MD, MPH, PhDPostdoctoral Scholar

Pediatric Infectious Diseases

What is Epi Info?

A free public domain software package developed by the Centers for Disease Control and Prevention for the global community of medical and public health professionals.

It can be used to rapidly: develop an electronic data entry form enter data into this form analyze data entered into this form or imported

from other software packages

Past, Present, and Future

First version: Epi Info 1 (MS-DOS) Released 1985

Latest version: Epi Info 3.5.1 Released 2008

Earlier this year, Epi Info became an “open source” software.

The next version (Epi Info 7) is currently being developed at the CDC’s National Center for Public Health Informatics.

Worldwide use

A study conducted in 2003 documented at least 1 million downloads in at least 180 countries.

Epi Info has been translated to several languages by different institutions and individuals around the world. Examples include: Spanish Italian Russian

Epi Info vs. other software packages

Epi Info has not been designed to replace: Professional data management software

packages such as:Microsoft AccessFileMaker Pro

Professional data analysis software packages such as:SASStataR

Advantages of Epi Info

Free User-friendly

Point-and-click All-in-one software

Design a data entry form, enter data, and analyze data

Time efficient Very useful for outbreak

investigations

Main applications in Epi Info

We will discuss these applications today: Make View

For designing an electronic data entry form which automatically creates a data table

Enter DataFor entering data into the designed electronic

data entry form Analyze Data

For conducting a relatively wide range of statistical analysis of the data

Other applications in Epi Info

We will not discuss these applications today: Create Maps (Epi Map)

For creating Geographic Information System (GIS) maps and overlaying survey data on to them

Create Reports (Epi Report)For presenting results in a professional format

NutStatA nutrition anthropometry program for

calculating BMI and growth Z scores/percentiles

Make View

Make View

View is an electronic data entry form that you design based on a questionnaire used for primary data collection.

Each view has a corresponding data table “in the background”. No spreadsheet is involved.

There are 17 field (i.e., variable) types that you can choose from (Text, Number, Date, Time, Check Box, Yes/No, Option, etc.)

You can also add check codes and skip patterns to your view all by point-and-click.

What is a check code?

Check codes are rules and restrictions that you add to your view in order to improve the accuracy or efficiency of the data entry process. Examples include: Making data entry for a particular variable

required Defining a range for a particular variable Making a variable “Read Only”

Create the view here

Define a new field (variable) by right-clicking on the view

Create a skip pattern

Add a check code

An example of a skip pattern

An example of a view with fields grouped together

and color-coded

Source: Epi Info tutorial “Rhodococcal Infection After Open-Heart Surgery”

Based on a hospital outbreak investigation conducted by an EIS officer. The report was

published in the New England Journal of Medicine (New Engl J Med 1991;324:104-9).

Enter Data

Enter Data

You can easily: enter data in the view that you have designed control the order of data entry process navigate through different records find a particular or a group of records according to

a criterion that you define

Analyze Data

Import/Export Data

You can import data generated in some other software packages Text, Excel, dBASE, Access

You can export data suitable for use in some other software packages Text, Excel, dBASE, Access

Data manipulation

You can perform a relatively wide range of common data manipulation procedures such as: Sorting data on a specific variable Recoding categories of a variable Defining a new variable

You can also merge records in one data table with those in another data table using a key (i.e., common) variable.

Statistical analysis (1)

Univariable analysis Measures of central tendency and dispersion

Mean, median, mode, quartiles, standard deviation, etc.

Bivariable analysis Chi-square and Fisher’s exact test t test and the analysis of variance (ANOVA) Odds ratio Risk ratio Risk difference

Statistical analysis (2)

Multivariable analysis Linear regression Logistic regression

Unconditional and conditional Survival analysis

Kaplan-MeierCox proportional hazard regression

You can create dummy variables and interaction terms all by point-and-click

Complex sample survey analysis

Analysis Output

Program Editor

Commands Tree

An Example

Cross-tabulation of smoking and case/control status

Graphics

Two Examples

A Kaplan-Meier Survival Curve

A Scatterplot

Some Useful Websites

CDC (http://www.cdc.gov/epiinfo)

User forum (http://cms.myepi.info)

North Carolina Center for Public Health Preparedness (Internet-based training)

Thank you!

Feel free to send an e-mail with any questions to:rowhani@stanford.edu