Introduction to epi data

Introduction to EPIDATA
Deﬁne Data/creating Questionnaire template
Add/Revise Checks - at Entry of Data
Document data ﬁle
Export Data
Introduction to EpiData
By:Zelalem Mehari(M.Sc. in Biostatistics)
Bahir Dar University
College of Medicine and Health Sciences
November 29, 2019, Bahir Dar, Ethiopia
1 / 35

Document data file
Export Data
Outlines
1 Introduction to EPIDATA
1 Define Data/creating Questionnaire template
1 Add/Revise Checks - at Entry of Data
1 Document data file
1 Export Data
2 / 35

Document data file
Export Data
Introduction to EpiData
EpiData is freeware and available from:http://www.epidata.
dk.
Data entry and documentation
Has a Windows format
No limit on No of observation (tested with >250.000)
User friendly with other statistical packages
EpiData not to interfere with the setup of your computer.
EpiData consists of one program file and a few help files.
No other files are installed.
In technical terms this means that EpiData does not install or
include any DLL files or system files - options are saved in
registry. 3 / 35

Document data file
Export Data
Major functions of EpiData
To design questionnaire
For Data entry
Comparing of 2 data files/double entry verification
Documenting and printing data
Correction of questionnaires, records
Importing and exporting data
Append and merge data
Simple analysis
4 / 35

Document data file
Export Data
EpiData files
.QES file
(EpiData Questionnaire file)
Questionnaire
.REC file
(EpiData Data file)
Actual data
.CHK file
(EpiData check file)
Any defined checks
.NOT file
(EpiData entry notes)
.LOG file 5 / 35

Document data ﬁle
Export Data
1 Deﬁne Data
2 Make Data File
3 Set up Checks
4 Enter Data
5 Document
6 Export Data
6 / 35

Document data ﬁle
Export Data
6 / 35

Document data file
Export Data
Opening Existing/Creating New Questionnaire File
Opening Existing Questionnaire
click on Define data− >Open.QES file
Before you begin create an EpiData Folder on your computer.
It is good file managementpractice to put all your files in the
same place
New Questionnaire can be created by either of the three
techniques
Type in window
Cut and paste from Word documents
By Clicking .QES file from REC file from the tools in the menu
bar
7 / 35

Document data ﬁle
Export Data
Opening Existing/Creating New Questionnaire File
8 / 35

Document data file
Export Data
Structure of questionnaire
Any Questionnaire file in EpiData has three sections:
1 Field name(variable)
2 Text describing field
3 Input/Field/Variable definition (number/ letters/ date)
9 / 35

Document data file
Export Data
Field name(variable)
Field name should fulfill the following Criteria:
No more than 10 characters
Begin with a letter
No spaces or punctuation marks
Names of the entry fields in a data form are created in two
different ways:
1 First word in the question (i.e. the text to the left of the field)
is used as the field name.
2 Automatic field naming according to the rules used by Epi Info
The method used depends upon the options defined in File /
Options / Create Data file.
10 / 35

Document data ﬁle
Export Data
Field name(variable)
11 / 35

Document data file
Export Data
First word as field name(varible name)
If the option First word in question is field name is selected
from File / Options / Create data file,
The names of the entry fields are created by using the first
word in the text to the left of the entry field.
If the length of the first word is more than 10 characters then
the first 10 characters of the first word will be used as field
name
Examples: If the question is ”Examination result of the
test”‘,the variable name will be ”Examinatio”
If the qestion is ”Laboratory Serial number”,then the field
name will be Laboratory
12 / 35

Document data file
Export Data
Automatic field names.......
If Automatic field names is selected in the Create data file
options (File − > Options− > Create data file− >Automatic
field names),
EpiData automatically generates field names based on the
field’s question (i.e. the text to the left of the field).
The field name is a maximum of 10 characters starting with a
letter. Letters used in the name are A-Z.
The field name is generated from the beginning of the field’s
question.
Rules used to generate field names:
Text enclosed in braces(curly brackets) will be the field names
Example: if the question is Result of specimen 2 {scanty},the
field name is scanty
13 / 35

Document data file
Export Data
Automatic field names.......
If the first character of the generated field name is a number
then the letter N is inserted at the first character
Example: ”1. age of patients” generates the field name
N1ageofpat.
Letter case of the field name is based on the settings used in
File− > option− >Create Data file
Upper case
Lower Case
Leave as it
14 / 35

Document data file
Export Data
Variable labels/Text describing field
A variable label is a description of the data that a field contains
If the option First word in question is field name is set then
the variable label will be the text to the left of the field
excluding the first word, which is used as the field name.
Example: in the line v1 weight of patient
If the option First word in question is field name is set, will
create the field name ”v1” and the variable label ”weight of
patient”.
If the option Automatic field naming is set then the field name
will be ”v1weightpa” and the variable label will be ”v1 weight
of patient”.
15 / 35

Document data ﬁle
Export Data
Variable/Field types in EpiData
Deﬁne variables using Pick List or Code writer
16 / 35

Document data file
Export Data
Text variables
Variables of information of text and/or numbers
Holding information (e.g. names, addresses)
UPPER CASE
Can only hold upper case (capital) letters
Lower case variable automatically converted into upper case
text (ex: Female converted to FEMALE)
No mathematical operations
Length (How many characters)
Encrypted fields-special type of text fields by < >
The number of underscore characters defines the length of the
field.
17 / 35

Document data file
Export Data
Numeric variables
Are variables of Numerical information
Hold integers (whole numbers) or numbers with a decimal
point.Maximum field length is 14 characters.
Length (digits, decimals after the comma)
Example ### , ###.### , ######## , ##.####
Numeric fields accept entry of numbers, the minus sign and
decimal points
Periods (.) as well as commas (,) are accepted as decimal
points in both the .QES file and during data entry.
Only one decimal point is accepted in a field.
This means that commas cannot be used as thousand
separators
18 / 35

Document data file
Export Data
Boolean Variables(yes/no fields)
Are logical or YES/NO variables
Variables with only two possible answers: Yes or No
<Y >
Boolean fields accept only Y, N, 1, 0 and space as legal entries
An entry of 1 is converted to Y.
An entry of 0 is converted to N.
Boolean fields have a length of one.
This means that a field code of <Y> in the .QES file will
create an error
This means that a field code of <Y > in the .QES file will
create an error
19 / 35

Document data file
Export Data
Date variables/ fields
Hold information on dates
There are three types of date fields:
European style dates (day/month/year), (dd/mm/yyyy)
American style dates (month/day/year), (mm/dd/yyyy)
”reversed dates” (year/month/day), (yyyy/mm/dd)
Date fields are always 10 characters in length
During data entry, legal characters are numbers and forward
slash (/)
Dates can be entered without using the slash character if all
numbers are written in full.
20 / 35

Document data ﬁle
Export Data
Soundex variables/ﬁelds
<S >
Soundex is a coding of words that can be used to anonymize
e.g. the surnames of informants participating in a survey.
A Soundex code is always in the format A-999, that is one
upper-case letter, a hyphen and 3 numbers.
The Soundex code is generated using the following rules:
21 / 35

Document data ﬁle
Export Data
Soundex variables/ﬁelds..
Consonants after the initial letter are coded in the order
The code always uses the initial letter plus three digits.
Further consonants in long words are ignored:
Zeros are used to pad out shorter names: BALL − > B-400
Double consonants are treated as one: BALL − > B-400
As are adjacent consonants from the same code group:
A consonant immediately following an initial letter from the
same code group is ignored: SCANLON− > S-545
Apostrophes and hyphens are
ignored:KING-SMITH− >KINGSMITH− > K-525
22 / 35

Document data file
Export Data
System variables/fields
Values generated automatically
Today date: date of the data entry
<Today-dmy>
<Today-mdy>
<Today-ymd>
Auto identification number:
Counts the records entered.
<IDNUM>
23 / 35

Document data file
Export Data
Save Questionnaire
Preview data
Save questionnaire
Creates .QES file
Create Data file
Click Make Data file button − > Make Data file
Creates.REC file
Questionnaire and Data file ready
But you have to control Errors in data entry
24 / 35

Document data ﬁle
Export Data
Errors in data entry
Tranposition (ex: 39 becomes 93)
Copying errors (0 copy as an ”o” letter)
Consistency errors: two or more responses are contradictory
(sex: man, pregnancy=Yes)
Range errors: answers outside of probable or possible values
(ex: heigh = 3 metres)
Preventing errors
Train data entry clerck
Validation: entering twice data by diﬀerent operators
Using Checks
25 / 35

Document data file
Export Data
Checks
Reduce errors in input
Checks help with data entry
Many different types
Limit entry of numbers to specific range
Forcing entry to be made in field
Conditional jumps
Copying the data from the previous record
Help messages
Conditional operations (e.g ifĚ.then operations)
Once Data file is created:
Click Checks button − > choose .REC file 26 / 35

Document data ﬁle
Export Data
checks
27 / 35

Document data file
Export Data
Value labels
Value labels are a set of values combined with text itemsthat
explain the meaning of each value.
For example: A field is created to enter information on the sex
of the informants’.
a value of 0 in the field means that the informant is male and
that a value of 1 means the informant is female.
The value labels in this example would be:
0 Male
1 Female
If a value label is defined then a ’translation table’ can be
shown during data entry if the user presses [F9]or the [+] key
on the numeric keypad).
28 / 35

Document data ﬁle
Export Data
Value labels...
29 / 35

Document data ﬁle
Export Data
Deleting a record
Deleting a record consists of two steps
marking a record for deletion;
second,permanently deleting it.
This is just a safety feature in EpiData to ensure the deletion
of record does not happen by chance
30 / 35

Document data ﬁle
Export Data
31 / 35

Document data file
Export Data
Document data file
File Structure
Data entry notes (.NOT file)
Use to write comments during data entry eg: difficult to read
handwriting etc
View Data
List Data
Codebook
Basic descriptive statistics on all variables
32 / 35

Document data ﬁle
Export Data
Export to other Software’s
Click Export data button
Choose the software
33 / 35

Document data ﬁle
Export Data
Export Data
The Export data function is found in the Data in/out menu
For Epi-info open .REC ﬁle directly 34 / 35

Document data ﬁle
Export Data
THANK YOU!
35 / 35

Introduction to epi data

More Related Content

What's hot (20)

Similar to Introduction to epi data (20)

Recently uploaded (20)

Introduction to epi data