Making Life Easy Using Epi Info: An Introduction

1
Making Life Easy Using Epi InfoAn Introduction

• Ali Rowhani-Rahbar, MD, MPH, PhD
• Postdoctoral Scholar
• Division of Infectious Diseases
• Department of Pediatrics

2
Presentation outline

• Introduction of Epi Info
• Overview of its applications, strengths, and
  limitations
• Description of its three main modules
• Each module will be discussed first followed by a
  few screenshots
• Make View
• Enter Data
• Analyze Data

3
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 (i.e.,
  questionnaire)
• Enter data into this form
• Analyze the entered data

4
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 CDCs National Center for Public
  Health Informatics.
• Visit Epi Info Museum at http//www.cdc.gov/epiin
  fo/background.htm

5
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
• French
• Russian
• Portuguese

6
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, MySQL, Oracle
• Professional data analysis software packages such
  as
• SAS, Stata, R, SPSS

7
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

8
Main modules

• Discussed today
• Make View (Questionnaire) For designing an
  electronic data entry form which automatically
  creates a data table(s)
• Epi Info is capable of creating a relational
  database.
• 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

9
Other modules

• Not discussed 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

10
(No Transcript)
11
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, create skip
  patterns, and even define new variables created
  by other variables automatically.

12
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 permissible for a particular variable
• Making a variable Read Only

13
Create the view here
Define a new field (variable) by right-clicking
on the view
14
Example Creating a Number field
15
(No Transcript)
16
Creating a drop down field using Legal Values
Adding a check code
17
(No Transcript)
18
Creating a skip pattern
19
Use the Program button to create a skip pattern
20
Determine where action will occur
21
Lets choose the If tab
22
(No Transcript)
23
(No Transcript)
24
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 1991324104-9).

25
(No Transcript)
26
(No Transcript)
27
(No Transcript)
28
(No Transcript)
29
Enter Data

• You can easily
• Enter data in the view that you have designed
• Control the order of data entry process
• Tab order
• Navigate through different records
• Find a particular or a group of records according
  to a criterion that you define
• You can print your view here

30
(No Transcript)
31
Example of a check code (1)

• Lets enter 3 for variable Case which has
  been coded as 1 if the participant is case and
  2 if the participant is control in a
  case-control study

32
(No Transcript)
33
Example of a check code (2)

• Lets enter a date as 20/02/2009 for variable
  Date Onset which has been coded in the
  MM/DD/YYYY format.

34
(No Transcript)
35
(No Transcript)
36
Import and export data

• You can import data generated in some other
  software packages such as
• Text, Excel, Access
• You can export data suitable for use in some
  other software packages such as
• Text, Excel, Access

37
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.

38
Statistical analysis (1)

• Univariable analysis
• Measures of central tendency and dispersion
• Mean, median, mode, quartiles, standard
  deviation, etc.
• Bivariable analysis
• Chi-square and Fishers exact test
• Odds ratio
• Risk ratio
• Risk difference
• t-test and the analysis of variance (ANOVA)
• Correlation coefficient

39
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

40
Analysis Output
Commands Tree
Program Editor
41
The corresponding data table

• Created in the background

42
(No Transcript)
43
An example of a simple analysis

• Cross-tabulation of smoking
• and case/control status

44
(No Transcript)
45
(No Transcript)
46
Graphics

• Two examples

47
A Kaplan-Meier Survival Curve
A Scatterplot
48
What about privacy?

• Use Epi Lock

49
(No Transcript)
50
(No Transcript)
51
Some useful resources
52
CDC (http//www.cdc.gov/epiinfo)
53
(No Transcript)
54
(No Transcript)
55
(No Transcript)
56
(No Transcript)
57
North Carolina Center for Public Health
Preparedness (Internet-based training)
58
Thank you!

• Contact information
• rowhani_at_stanford.edu