1. Making Life Easy Using Epi Info: An Introduction Ali Rowhani-Rahbar, MD, MPH, PhD Postdoctoral Scholar Pediatric Infectious Diseases

2. 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

3. 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.

4. 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

5. Epi Info vs. other software packages  Epi Info has not been designed to replace:  Professional data management software packages such as: Microsoft Access FileMaker Pro  Professional data analysis software packages such as: SAS Stata R

6. 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

7. 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 Data For entering data into the designed electronic data entry form  Analyze Data For conducting a relatively wide range of statistical analysis of the data

8. 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  NutStat A nutrition anthropometry program for calculating BMI and growth Z scores/percentiles

9. Make View

10.  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.

11. 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”

12. Create the view here

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

14. Create a skip pattern Add a check code

15. An example of a skip pattern

16. 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).

18. Enter Data

19.  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

21. Analyze Data

22. 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

23. 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.

24. 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

25. Statistical analysis (2)  Multivariable analysis  Linear regression  Logistic regression Unconditional and conditional  Survival analysis Kaplan-Meier Cox proportional hazard regression  You can create dummy variables and interaction terms all by point-and-click  Complex sample survey analysis

26. Analysis Output Program Editor Commands Tree

27. An Example Cross-tabulation of smoking and case/control status

30. Graphics Two Examples

31. A Kaplan-Meier Survival Curve A Scatterplot

32. Some Useful Websites

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

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

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

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