Epi Info is a free public domain software program developed by the CDC for data entry, analysis, and reporting. It allows users to develop electronic data entry forms, enter and analyze data, and produce statistics, graphs, tables, and maps. The main applications in Epi Info include designing data entry forms, entering data using these forms, and analyzing the entered data using a wide range of statistical tests. Sample size calculations can also be performed using Epi Info to determine the necessary sample sizes for different study designs like population surveys, case control studies, and cross-sectional or cohort studies.

1. Introduction to Epi Info
Emiru Merdassa
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2. 2
–Overview of EPI-Info
–Data entry using EPI-INFO
–Sample size determination
Outline
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3. 3
• Epi Info is a public domain database and statistics program.
– Develop an electronic data entry form
– Customize the data entry process
– Enter data, and analyze the data
– Statistics, graphs, tables, and maps can be produced with simple commands
– Epi Info is free, downloadable software provided by the CDC
(www.cdc.gov/epiinfo)
Introduction
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4. 4
• 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.
Main applications in Epi Info
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5. The Epi-Info 7 Main Menu
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6. Epi Info – Core Principles
–Free
–Easy to use
–Flexible
–Standards based
–No “IT guys” needed in most cases
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7. Designing a Form
❑ The Form Designer has several “work areas”
▪ The Menu
– The toolbar contains buttons for creating projects, editing the form’s check code,
going to the data entry module, and undo/redo.
▪ The Project Explorer is where you can add and remove forms from your project,
add, edit, and remove pages from individual forms, and work with templates.
▪ The Canvas is where fields are placed, moved, and edited.

8. Designing a Form
1. The Menu
2. The Project Explorer
3. The Canvas

9. Creating question/prompt
Choice one
of the
property for
the variable
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10. Sample Size determination using Epi Info
• Step 1: Go to the main menu at the top left corner and click on StatCalc and subsequent
options
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11. Sample size determination
• Fill the components necessary to determine sample size for the three case scenarios:
Population survey, Unmatched case control, and Cross-sectional or Cohort study
designs.
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12. Exercise
Let us assume the population that we want to conduct the study has a target
population of size N=100,000, and the proportion of the variable of interest is not
known which means there is no previous study done and hence we decided to use 50
percent as an estimate of the prevalence for that variable.
a) What would be the sample size required if the sampling technique was simple
random sampling?
b) What will be the sample size if the sampling technique is two stage sampling
and is also expected to have 10% non-response rate?
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13. Exercise
• The prevalence of under weight of newborns is compared between two
regions. In one region, it is estimated that about 30% of them could be under
weight. In other region it is probably 15%. If the required sample is to show
with a 90% likelihood (power) that the percentage of newborns is different in
these two regions at 95% confidence level, what would be the sample size?
Suppose that the current study uses multistage sampling and another similar
study has reported 91.5% response rate.
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14. Thank you
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